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Bibliography on: Sociobiology

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ESP: PubMed Auto Bibliography 14 Nov 2022 at 02:05 Created: 

Sociobiology

Sociobiology is a field of scientific study that is based on the hypothesis that social behavior has resulted from evolution and attempts to examine and explain social behavior within that context. Sociobiology investigates social behaviors, such as mating patterns, territorial fights, pack hunting, and the hive society of social insects. It argues that just as selection pressure led to animals evolving useful ways of interacting with the natural environment, it led to the genetic evolution of advantageous social behavior. While the term "sociobiology" can be traced to the 1940s, the concept did not gain major recognition until the publication of Edward O. Wilson's book Sociobiology: The New Synthesis in 1975.

Created with PubMed® Query: sociobiology NOT pmcbook NOT ispreviousversion

Citations The Papers (from PubMed®)

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RevDate: 2022-11-07

Maestripieri D, BB Boutwell (2022)

Human nature and personality variation: Reconnecting evolutionary psychology with the science of individual differences.

Neuroscience and biobehavioral reviews pii:S0149-7634(22)00435-3 [Epub ahead of print].

The scientific study of human behavior from a modern evolutionary perspective began in the 20th century with disciplines such as human ethology and behavioral ecology as well as sociobiology. This early work focused on the characterization of a universal human nature that could be observed across all societies and cultures, one believed to have emerged in part from evolutionary processes. With the passage of time a newer evolutionary discipline, evolutionary psychology, emerged in the early 1990s and quickly flourished. The focus on human nature was retained from its forerunners, but the primary focus of the field underwent a decided shift. Gone was the emphasis on observable behaviors and in its place moved psychological and cognitive functioning. At the same time, the new field took an interesting departure from other branches of psychology by largely relegating the significance of individual differences across cognitive and personality styles (whether heritable or environmental in origin) to a minor role. In this paper, we review the primary original arguments for minimizing or ignoring the importance of individual differences in personality and cognition, all in the service of making the case that the study of human nature, and evolutionary psychology more generally, is not at odds with individual differences research. The two fields have always been complementary, with one serving as a frequent source of insight for the other.

RevDate: 2022-10-31
CmpDate: 2022-10-31

Simberloff D (2022)

In Memoriam : Edward O. Wilson (1929-2021): It All Started with Ants.

The American naturalist, 200(5):627-633.

RevDate: 2022-10-29

Kappeler PM, Benhaiem S, Fichtel C, et al (2022)

Sex roles and sex ratios in animals.

Biological reviews of the Cambridge Philosophical Society [Epub ahead of print].

In species with separate sexes, females and males often differ in their morphology, physiology and behaviour. Such sex-specific traits are functionally linked to variation in reproductive competition, mate choice and parental care, which have all been linked to sex roles. At the 150th anniversary of Darwin's theory on sexual selection, the question of why patterns of sex roles vary within and across species remains a key topic in behavioural and evolutionary ecology. New theoretical, experimental and comparative evidence suggests that variation in the adult sex ratio (ASR) is a key driver of variation in sex roles. Here, we first define and discuss the historical emergence of the sex role concept, including recent criticisms and rebuttals. Second, we review the various sex ratios with a focus on ASR, and explore its theoretical links to sex roles. Third, we explore the causes, and especially the consequences, of biased ASRs, focusing on the results of correlational and experimental studies of the effect of ASR variation on mate choice, sexual conflict, parental care and mating systems, social behaviour, hormone physiology and fitness. We present evidence that animals in diverse societies are sensitive to variation in local ASR, even on short timescales, and propose explanations for conflicting results. We conclude with an overview of open questions in this field integrating demography, life history and behaviour.

RevDate: 2022-10-29

Schmid K, Knote A, Mück A, et al (2021)

Interactive, Visual Simulation of a Spatio-Temporal Model of Gas Exchange in the Human Alveolus.

Frontiers in bioinformatics, 1:774300.

In interdisciplinary fields such as systems biology, good communication between experimentalists and theorists is crucial for the success of a project. Theoretical modeling in physiology usually describes complex systems with many interdependencies. On one hand, these models have to be grounded on experimental data. On the other hand, experimenters must be able to understand the interdependent complexities of the theoretical model in order to interpret the model's results in the physiological context. We promote interactive, visual simulations as an engaging way to present theoretical models in physiology and to make complex processes tangible. Based on a requirements analysis, we developed a new model for gas exchange in the human alveolus in combination with an interactive simulation software named Alvin. Alvin exceeds the current standard with its spatio-temporal resolution and a combination of visual and quantitative feedback. In Alvin, the course of the simulation can be traced in a three-dimensional rendering of an alveolus and dynamic plots. The user can interact by configuring essential model parameters. Alvin allows to run and compare multiple simulation instances simultaneously. We exemplified the use of Alvin for research by identifying unknown dependencies in published experimental data. Employing a detailed questionnaire, we showed the benefits of Alvin for education. We postulate that interactive, visual simulation of theoretical models, as we have implemented with Alvin on respiratory processes in the alveolus, can be of great help for communication between specialists and thereby advancing research.

RevDate: 2022-10-19

Broekman MJE, Hilbers JP, Huijbregts MAJ, et al (2022)

Evaluating expert-based habitat suitability information of terrestrial mammals with GPS-tracking data.

Global ecology and biogeography : a journal of macroecology, 31(8):1526-1541.

Aim: Macroecological studies that require habitat suitability data for many species often derive this information from expert opinion. However, expert-based information is inherently subjective and thus prone to errors. The increasing availability of GPS tracking data offers opportunities to evaluate and supplement expert-based information with detailed empirical evidence. Here, we compared expert-based habitat suitability information from the International Union for Conservation of Nature (IUCN) with habitat suitability information derived from GPS-tracking data of 1,498 individuals from 49 mammal species.

Location: Worldwide.

Time period: 1998-2021.

Major taxa studied: Forty-nine terrestrial mammal species.

Methods: Using GPS data, we estimated two measures of habitat suitability for each individual animal: proportional habitat use (proportion of GPS locations within a habitat type), and selection ratio (habitat use relative to its availability). For each individual we then evaluated whether the GPS-based habitat suitability measures were in agreement with the IUCN data. To that end, we calculated the probability that the ranking of empirical habitat suitability measures was in agreement with IUCN's classification into suitable, marginal and unsuitable habitat types.

Results: IUCN habitat suitability data were in accordance with the GPS data (> 95% probability of agreement) for 33 out of 49 species based on proportional habitat use estimates and for 25 out of 49 species based on selection ratios. In addition, 37 and 34 species had a > 50% probability of agreement based on proportional habitat use and selection ratios, respectively.

Main conclusions: We show how GPS-tracking data can be used to evaluate IUCN habitat suitability data. Our findings indicate that for the majority of species included in this study, it is appropriate to use IUCN habitat suitability data in macroecological studies. Furthermore, we show that GPS-tracking data can be used to identify and prioritize species and habitat types for re-evaluation of IUCN habitat suitability data.

RevDate: 2022-10-15

Kaya-Zeeb S, Delac S, Wolf L, et al (2022)

Robustness of the honeybee neuro-muscular octopaminergic system in the face of cold stress.

Frontiers in physiology, 13:1002740.

In recent decades, our planet has undergone dramatic environmental changes resulting in the loss of numerous species. This contrasts with species that can adapt quickly to rapidly changing ambient conditions, which require physiological plasticity and must occur rapidly. The Western honeybee (Apis mellifera) apparently meets this challenge with remarkable success, as this species is adapted to numerous climates, resulting in an almost worldwide distribution. Here, coordinated individual thermoregulatory activities ensure survival at the colony level and thus the transmission of genetic material. Recently, we showed that shivering thermogenesis, which is critical for honeybee thermoregulation, depends on octopamine signaling. In this study, we tested the hypothesis that the thoracic neuro-muscular octopaminergic system strives for a steady-state equilibrium under cold stress to maintain endogenous thermogenesis. We can show that this applies for both, octopamine provision by flight muscle innervating neurons and octopamine receptor expression in the flight muscles. Additionally, we discovered alternative splicing for AmOARβ2. At least the expression of one isoform is needed to survive cold stress conditions. We assume that the thoracic neuro-muscular octopaminergic system is finely tuned in order to contribute decisively to survival in a changing environment.

RevDate: 2022-10-12
CmpDate: 2022-10-12

Eppley TM, Hoeks S, Chapman CA, et al (2022)

Factors influencing terrestriality in primates of the Americas and Madagascar.

Proceedings of the National Academy of Sciences of the United States of America, 119(42):e2121105119.

Among mammals, the order Primates is exceptional in having a high taxonomic richness in which the taxa are arboreal, semiterrestrial, or terrestrial. Although habitual terrestriality is pervasive among the apes and African and Asian monkeys (catarrhines), it is largely absent among monkeys of the Americas (platyrrhines), as well as galagos, lemurs, and lorises (strepsirrhines), which are mostly arboreal. Numerous ecological drivers and species-specific factors are suggested to set the conditions for an evolutionary shift from arboreality to terrestriality, and current environmental conditions may provide analogous scenarios to those transitional periods. Therefore, we investigated predominantly arboreal, diurnal primate genera from the Americas and Madagascar that lack fully terrestrial taxa, to determine whether ecological drivers (habitat canopy cover, predation risk, maximum temperature, precipitation, primate species richness, human population density, and distance to roads) or species-specific traits (body mass, group size, and degree of frugivory) associate with increased terrestriality. We collated 150,961 observation hours across 2,227 months from 47 species at 20 sites in Madagascar and 48 sites in the Americas. Multiple factors were associated with ground use in these otherwise arboreal species, including increased temperature, a decrease in canopy cover, a dietary shift away from frugivory, and larger group size. These factors mostly explain intraspecific differences in terrestriality. As humanity modifies habitats and causes climate change, our results suggest that species already inhabiting hot, sparsely canopied sites, and exhibiting more generalized diets, are more likely to shift toward greater ground use.

RevDate: 2022-09-20

Pfeiffer K (2022)

The neuronal building blocks of the navigational toolkit in the central complex of insects.

Current opinion in insect science pii:S2214-5745(22)00107-9 [Epub ahead of print].

The central complex in the brain of insects is a group of midline-spanning neuropils at the interface between sensory and premotor tasks of the brain. It is involved in sleep control, decision making and most prominently in goal-directed locomotion behaviors. The recently published connectome of the central complex of Drosophila melanogaster is a milestone in understanding the intricacies of the central complex circuits and will provide inspiration for testable hypotheses for the coming years. Here I provide a basic neuroanatomical description of the central complex of Drosophila and other species and discuss some recent advancements, some of which, like the discovery of coordinate transformation through vector math, have been predicted from connectomics data.

RevDate: 2022-10-11
CmpDate: 2022-09-22

Schultheiss P, Nooten SS, Wang R, et al (2022)

The abundance, biomass, and distribution of ants on Earth.

Proceedings of the National Academy of Sciences of the United States of America, 119(40):e2201550119.

Knowledge on the distribution and abundance of organisms is fundamental to understanding their roles within ecosystems and their ecological importance for other taxa. Such knowledge is currently lacking for insects, which have long been regarded as the "little things that run the world". Even for ubiquitous insects, such as ants, which are of tremendous ecological significance, there is currently neither a reliable estimate of their total number on Earth nor of their abundance in particular biomes or habitats. We compile data on ground-dwelling and arboreal ants to obtain an empirical estimate of global ant abundance. Our analysis is based on 489 studies, spanning all continents, major biomes, and habitats. We conservatively estimate total abundance of ground-dwelling ants at over 3 × 1015 and estimate the number of all ants on Earth to be almost 20 × 1015 individuals. The latter corresponds to a biomass of ∼12 megatons of dry carbon. This exceeds the combined biomass of wild birds and mammals and is equivalent to ∼20% of human biomass. Abundances of ground-dwelling ants are strongly concentrated in tropical and subtropical regions but vary substantially across habitats. The density of leaf-litter ants is highest in forests, while the numbers of actively ground-foraging ants are highest in arid regions. This study highlights the central role ants play in terrestrial ecosystems but also major ecological and geographic gaps in our current knowledge. Our results provide a crucial baseline for exploring environmental drivers of ant-abundance patterns and for tracking the responses of insects to environmental change.

RevDate: 2022-09-17
CmpDate: 2022-09-08

Yilmaz A, J Spaethe (2022)

Colour vision in ants (Formicidae, Hymenoptera).

Philosophical transactions of the Royal Society of London. Series B, Biological sciences, 377(1862):20210291.

Ants are ecologically one of the most important groups of insects and exhibit impressive capabilities for visual learning and orientation. Studies on numerous ant species demonstrate that ants can learn to discriminate between different colours irrespective of light intensity and modify their behaviour accordingly. However, the findings across species are variable and inconsistent, suggesting that our understanding of colour vision in ants and what roles ecological and phylogenetic factors play is at an early stage. This review provides a brief synopsis of the critical findings of the past century of research by compiling studies that address molecular, physiological and behavioural aspects of ant colour vision. With this, we aim to improve our understanding of colour vision and to gain deeper insights into the mysterious and colourful world of ants. This article is part of the theme issue 'Understanding colour vision: molecular, physiological, neuronal and behavioural studies in arthropods'.

RevDate: 2022-08-18
CmpDate: 2022-08-09

Fichtel C, PM Kappeler (2022)

Coevolution of social and communicative complexity in lemurs.

Philosophical transactions of the Royal Society of London. Series B, Biological sciences, 377(1860):20210297.

The endemic lemurs of Madagascar (Lemuriformes: Primates) exhibit great social and communicative diversity. Given their independent evolutionary history, lemurs provide an excellent opportunity to identify fundamental principles in the coevolution of social and communicative traits. We conducted comparative phylogenetic analyses to examine patterns of interspecific variation among measures of social complexity and repertoire sizes in the vocal, olfactory and visual modality, while controlling for environmental factors such as habitat and number of sympatric species. We also examined potential trade-offs in signal evolution as well as coevolution between body mass or brain size and communicative complexity. Repertoire sizes in the vocal, olfactory and visual modality correlated positively with group size, but not with environmental factors. Evolutionary changes in social complexity presumably antedated corresponding changes in communicative complexity. There was no trade-off in the evolution of signals in different modalities and neither body mass nor brain size correlated with any repertoire size. Hence, communicative complexity coevolved with social complexity across different modalities, possibly to service social relationships flexibly and effectively in pair- and group-living species. Our analyses shed light on the requirements and adaptive possibilities in the coevolution of core elements of social organization and social structure in a basal primate lineage. This article is part of the theme issue 'Cognition, communication and social bonds in primates'.

RevDate: 2022-08-12
CmpDate: 2022-08-02

Song 宋紫檀 Z, Liker A, Liu 刘阳 Y, et al (2022)

Evolution of Social Organization: Phylogenetic Analyses of Ecology and Sexual Selection in Weavers.

The American naturalist, 200(2):250-263.

AbstractCrook published a landmark study on the social organization of weavers (or weaverbirds, family Ploceidae) that contributed to the emergence of sociobiology, behavioral ecology, and phylogenetic comparative methods. By comparing ecology, spatial distribution, and mating systems, Crook suggested that the spatial distribution of food resources and breeding habitats influence weaver aggregation during both the nonbreeding season (flocking vs. solitary foraging) and the breeding season (colonial vs. solitary breeding), and the latter in turn impacts mating systems and sexual selection. Although Crook's study stimulated much follow-up research, his conclusions have not been scrutinized using phylogenetically controlled analyses. We revisited Crook's hypotheses using modern phylogenetic comparative methods on an extended data set of 107 weaver species. We showed that both diet and habitat type are associated with spatial distribution and that the latter predicts mating system, consistent with Crook's propositions. The best-supported phylogenetic path model also supported Crook's arguments and uncovered a direct relationship between nonbreeding distribution and mating system. Taken together, our phylogenetically corrected analyses confirm Crook's conjectures on the roles of ecology in social organizations of weavers; however, our analyses also uncovered an association between nonbreeding distributions and mating systems, which was not envisaged by Crook.

RevDate: 2022-07-31

Stöckl A, Grittner R, Taylor G, et al (2022)

Allometric scaling of a superposition eye optimizes sensitivity and acuity in large and small hawkmoths.

Proceedings. Biological sciences, 289(1979):20220758.

Animals vary widely in body size within and across species. This has consequences for the function of organs and body parts in both large and small individuals. How these scale, in relation to body size, reveals evolutionary investment strategies, often resulting in trade-offs between functions. Eyes exemplify these trade-offs, as they are limited by their absolute size in two key performance features: sensitivity and spatial acuity. Due to their size polymorphism, insect compound eyes are ideal models for studying the allometric scaling of eye performance. Previous work on apposition compound eyes revealed that allometric scaling led to poorer spatial resolution and visual sensitivity in small individuals, across a range of insect species. Here, we used X-ray microtomography to investigate allometric scaling in superposition compound eyes-the second most common eye type in insects-for the first time. Our results reveal a novel strategy to cope with the trade-off between sensitivity and spatial acuity, as we show that the eyes of the hummingbird hawkmoth retain an optimal balance between these performance measures across all body sizes.

RevDate: 2022-10-11
CmpDate: 2022-09-28

Tiley GP, van Elst T, Teixeira H, et al (2022)

Population genomic structure in Goodman's mouse lemur reveals long-standing separation of Madagascar's Central Highlands and eastern rainforests.

Molecular ecology, 31(19):4901-4918.

Madagascar's Central Highlands are largely composed of grasslands, interspersed with patches of forest. The historical perspective was that Madagascar's grasslands had anthropogenic origins, but emerging evidence suggests that grasslands were a component of the pre-human Central Highlands vegetation. Consequently, there is now vigorous debate regarding the extent to which these grasslands have expanded due to anthropogenic pressures. Here, we shed light on the temporal dynamics of Madagascar's vegetative composition by conducting a population genomic investigation of Goodman's mouse lemur (Microcebus lehilahytsara; Cheirogaleidae). These small-bodied primates occur both in Madagascar's eastern rainforests and in the Central Highlands, making them a valuable indicator species. Population divergences among forest-dwelling mammals will reflect changes to their habitat, including fragmentation, whereas patterns of post-divergence gene flow can reveal formerly wooded migration corridors. To explore these patterns, we used RADseq data to infer population genetic structure, demographic models of post-divergence gene flow, and population size change through time. The results offer evidence that open habitats are an ancient component of the Central Highlands, and that widespread forest fragmentation occurred naturally during a period of decreased precipitation near the last glacial maximum. Models of gene flow suggest that migration across the Central Highlands has been possible from the Pleistocene through the recent Holocene via riparian corridors. Though our findings support the hypothesis that Central Highland grasslands predate human arrival, we also find evidence for human-mediated population declines. This highlights the extent to which species imminently threatened by human-mediated deforestation may already be vulnerable from paleoclimatic conditions.

RevDate: 2022-08-10
CmpDate: 2022-07-21

van der Kooi CJ, J Spaethe (2022)

Caution with colour calculations: spectral purity is a poor descriptor of flower colour visibility.

Annals of botany, 130(1):1-9.

BACKGROUND: The colours of flowers are of key interest to plant and pollination biologists. An increasing number of studies have investigated the importance of saturation of flower colours (often called 'spectral purity' or 'chroma') for visibility to pollinators, but the conceptual, physiological and behavioural foundations for these metrics as well as the calculations used rest on slender foundations.

METHODS: We discuss the caveats of colour attributes that are derived from human perception, and in particular spectral purity and chroma, as variables in flower colour analysis. We re-analysed seven published datasets encompassing 774 measured reflectance spectra to test for correlations between colour contrast, spectral purity and chroma.

MAIN FINDINGS AND CONCLUSIONS: We identify several concerns with common calculation procedures in animal colour spaces. Studies on animal colour vision provide no ground to assume that any pollinator perceives (or responds to) saturation, chroma or spectral purity in the way humans do. A re-analysis of published datasets revealed that values for colour contrast between flowers and their background are highly correlated with measures for spectral purity and chroma, which invalidates treating these factors as independent variables as is currently commonplace. Strikingly, spectral purity and chroma - both of which are metrics for saturation and are often used synonymously - are not correlated at all. We conclude that alternative, behaviourally validated metrics for the visibility of flowers to pollinators, such as colour contrast and achromatic contrast, are better in understanding the role of flower colour in plant-pollinator signalling.

RevDate: 2022-08-16
CmpDate: 2022-06-20

Hudel L, PM Kappeler (2022)

Sex-specific movement ecology of the shortest-lived tetrapod during the mating season.

Scientific reports, 12(1):10053.

Sex-specific reproductive strategies are shaped by the distribution of potential mates in space and time. Labord's chameleon (Furcifer labordi) from southwestern Madagascar is the shortest-lived tetrapod whose life-time mating opportunities are restricted to a few weeks. Given that these chameleons grow to sexual maturity within about three months and that all individuals die soon after breeding, their mating strategies should be adapted to these temporal constraints. The reproductive tactics of this or any other Malagasy chameleon species have not been studied, however. Radio-tracking and observations of 21 females and 18 males revealed that females exhibit high site fidelity, move small cumulative and linear distances, have low corresponding dispersal ratios and small occurrence distributions. In contrast, males moved larger distances in less predictable fashion, resulting in dispersal ratios and occurrence distributions 7-14 times larger than those of females, and males also had greater ranges of their vertical distribution. Despite synchronous hatching, males exhibited substantial inter-individual variation in body mass and snout-vent length that was significantly greater than in females, but apparently unrelated to their spatial tactics. Females mated with up to 6 individually-known mates, but frequent encounters with unmarked individuals indicate that much higher number of matings may be common, as are damaging fights among males. Thus, unlike perennial chameleons, F. labordi males do not seem to maintain and defend territories. Instead, they invest vastly more time and energy into locomotion for their body size than other species. Pronounced variation in key somatic traits may hint at the existence of alternative reproductive tactics, but its causes and consequences require further study. This first preliminary study of the mating system of a Malagasy chameleon indicates that, as in other semelparous tetrapods, accelerated life histories are tied to a mating system with intense contest and scramble competition among males.

RevDate: 2022-09-01
CmpDate: 2022-07-15

Davidian E, Surbeck M, Lukas D, et al (2022)

The eco-evolutionary landscape of power relationships between males and females.

Trends in ecology & evolution, 37(8):706-718.

In animal societies, control over resources and reproduction is often biased towards one sex. Yet, the ecological and evolutionary underpinnings of male-female power asymmetries remain poorly understood. We outline a comprehensive framework to quantify and predict the dynamics of male-female power relationships within and across mammalian species. We show that male-female power relationships are more nuanced and flexible than previously acknowledged. We then propose that enhanced reproductive control over when and with whom to mate predicts social empowerment across ecological and evolutionary contexts. The framework explains distinct pathways to sex-biased power: coercion and male-biased dimorphism constitute a co-evolutionary highway to male power, whereas female power emerges through multiple physiological, morphological, behavioural, and socioecological pathways.

RevDate: 2022-10-19
CmpDate: 2022-07-29

Kaiser A, Hensgen R, Tschirner K, et al (2022)

A three-dimensional atlas of the honeybee central complex, associated neuropils and peptidergic layers of the central body.

The Journal of comparative neurology, 530(14):2416-2438.

The central complex (CX) in the brain of insects is a highly conserved group of midline-spanning neuropils consisting of the upper and lower division of the central body, the protocerebral bridge, and the paired noduli. These neuropils are the substrate for a number of behaviors, most prominently goal-oriented locomotion. Honeybees have been a model organism for sky-compass orientation for more than 70 years, but there is still very limited knowledge about the structure and function of their CX. To advance and facilitate research on this brain area, we created a high-resolution three-dimensional atlas of the honeybee's CX and associated neuropils, including the posterior optic tubercles, the bulbs, and the anterior optic tubercles. To this end, we developed a modified version of the iterative shape averaging technique, which allowed us to achieve high volumetric accuracy of the neuropil models. For a finer definition of spatial locations within the central body, we defined layers based on immunostaining against the neuropeptides locustatachykinin, FMRFamide, gastrin/cholecystokinin, and allatostatin and included them into the atlas by elastic registration. Our honeybee CX atlas provides a platform for future neuroanatomical work.

RevDate: 2022-07-16

Schmalz F, El Jundi B, Rössler W, et al (2022)

Categorizing Visual Information in Subpopulations of Honeybee Mushroom Body Output Neurons.

Frontiers in physiology, 13:866807.

Multisensory integration plays a central role in perception, as all behaviors usually require the input of different sensory signals. For instance, for a foraging honeybee the association of a food source includes the combination of olfactory and visual cues to be categorized as a flower. Moreover, homing after successful foraging using celestial cues and the panoramic scenery may be dominated by visual cues. Hence, dependent on the context, one modality might be leading and influence the processing of other modalities. To unravel the complex neural mechanisms behind this process we studied honeybee mushroom body output neurons (MBON). MBONs represent the first processing level after olfactory-visual convergence in the honeybee brain. This was physiologically confirmed in our previous study by characterizing a subpopulation of multisensory MBONs. These neurons categorize incoming sensory inputs into olfactory, visual, and olfactory-visual information. However, in addition to multisensory units a prominent population of MBONs was sensitive to visual cues only. Therefore, we asked which visual features might be represented at this high-order integration level. Using extracellular, multi-unit recordings in combination with visual and olfactory stimulation, we separated MBONs with multisensory responses from purely visually driven MBONs. Further analysis revealed, for the first time, that visually driven MBONs of both groups encode detailed aspects within this individual modality, such as light intensity and light identity. Moreover, we show that these features are separated by different MBON subpopulations, for example by extracting information about brightness and wavelength. Most interestingly, the latter MBON population was tuned to separate UV-light from other light stimuli, which were only poorly differentiated from each other. A third MBON subpopulation was neither tuned to brightness nor to wavelength and encoded the general presence of light. Taken together, our results support the view that the mushroom body, a high-order sensory integration, learning and memory center in the insect brain, categorizes sensory information by separating different behaviorally relevant aspects of the multisensory scenery and that these categories are channeled into distinct MBON subpopulations.

RevDate: 2022-09-07
CmpDate: 2022-05-24

Zupanc GKH, W Rössler (2022)

Government funding of research beyond biomedicine: challenges and opportunities for neuroethology.

Journal of comparative physiology. A, Neuroethology, sensory, neural, and behavioral physiology, 208(3):443-456.

Curiosity-driven research is fundamental for neuroethology and depends crucially on governmental funding. Here, we highlight similarities and differences in funding of curiosity-driven research across countries by comparing two major funding agencies-the National Science Foundation (NSF) in the United States and the German Research Foundation (Deutsche Forschungsgemeinschaft, DFG). We interviewed representatives from each of the two agencies, focusing on general funding trends, levels of young investigator support, career-life balance, and international collaborations. While our analysis revealed a negative trend in NSF funding of biological research, including curiosity-driven research, German researchers in these areas have benefited from a robust positive trend in DFG funding. The main reason for the decrease in curiosity-driven research in the US is that the NSF has only partially been able to compensate for the funding gap resulting from the National Institutes of Health restricting their support to biomedical research using select model organisms. Notwithstanding some differences in funding programs, particularly those relevant for scientists in the postdoctoral phase, both the NSF and DFG clearly support curiosity-driven research.

RevDate: 2022-07-31
CmpDate: 2022-06-13

Stuhrmann C (2022)

"It Felt More like a Revolution." How Behavioral Ecology Succeeded Ethology, 1970-1990.

Berichte zur Wissenschaftsgeschichte, 45(1-2):135-163.

As soon as ethology's status diminished in the early 1970s, it was confronted with two successor disciplines, sociobiology and behavioral ecology. They were able to challenge ethology because it no longer provided markers of strong disciplinarity such as theoretical coherence, leading figures and a clear identity. While behavioral ecology developed organically out of the UK ethological research community into its own disciplinary standing, sociobiology presented itself as a US competitor to the ethological tradition. I will show how behavioral ecology took the role of legitimate heir to ethology by rebuilding a theoretical core and an intellectual sense of community, while sociobiology failed to use its public appeal to reach disciplinary status. Meanwhile, ethology changed its disciplinary identity to encompass all biological studies of animal behavior.

RevDate: 2022-07-16
CmpDate: 2022-04-27

Römer D, Aguilar GP, Meyer A, et al (2022)

Symbiont demand guides resource supply: leaf-cutting ants preferentially deliver their harvested fragments to undernourished fungus gardens.

Die Naturwissenschaften, 109(3):25.

Leaf-cutting ants are highly successful herbivores in the Neotropics. They forage large amounts of fresh plant material to nourish a symbiotic fungus that sustains the colony. It is unknown how workers organize the intra-nest distribution of resources, and whether they respond to increasing demands in some fungus gardens by adjusting the amount of delivered resources accordingly. In laboratory experiments, we analyzed the spatial distribution of collected leaf fragments among nest chambers in Acromyrmex ambiguus leaf-cutting ants, and how it changed when one of the fungus gardens experienced undernourishment. Plant fragments were evenly distributed among nest chambers when the fungal symbiont was well nourished. That pattern changed when one of the fungus gardens was undernourished and had a higher leaf demand, resulting in more leaf discs delivered to the undernourished fungus garden over at least 2 days after deprivation. Some ants bypassed nourished gardens to directly deliver their resource to the chamber with higher nutritional demand. We hypothesize that cues arising from that chamber might be used for orientation and/or that informed individuals, presumably stemming from the undernourished chamber, may preferentially orient to them.

RevDate: 2022-04-05

Wilson Horch H, Rössler W, G Tavosanis (2022)

Editorial: Structural Plasticity of Invertebrate Neural Systems.

Frontiers in physiology, 13:874999.

RevDate: 2022-05-05
CmpDate: 2022-04-05

Smith JE, Fichtel C, Holmes RK, et al (2022)

Sex bias in intergroup conflict and collective movements among social mammals: male warriors and female guides.

Philosophical transactions of the Royal Society of London. Series B, Biological sciences, 377(1851):20210142.

Intergroup conflict is a major evolutionary force shaping animal and human societies. Males and females should, on average, experience different costs and benefits for participating in collective action. Specifically, among mammals, male fitness is generally limited by access to mates whereas females are limited by access to food and safety. Here we analyse sex biases among 72 species of group-living mammals in two contexts: intergroup conflict and collective movements. Our comparative phylogenetic analyses show that the modal mammalian pattern is male-biased participation in intergroup conflict and female-biased leadership in collective movements. However, the probability of male-biased participation in intergroup conflicts decreased and female-biased participation increased with female-biased leadership in movements. Thus, female-biased participation in intergroup conflict only emerged in species with female-biased leadership in collective movements, such as in spotted hyenas and some lemurs. Sex differences are probably attributable to costs and benefits of participating in collective movements (e.g. towards food, water, safety) and intergroup conflict (e.g. access to mates or resources, risk of injury). Our comparative review offers new insights into the factors shaping sex bias in leadership across social mammals and is consistent with the 'male warrior hypothesis' which posits evolved sex differences in human intergroup psychology. This article is part of the theme issue 'Intergroup conflict across taxa'.

RevDate: 2022-05-11
CmpDate: 2022-04-05

Peckre LR, Michiels A, Socias-Martínez L, et al (2022)

Sex differences in audience effects on anogenital scent marking in the red-fronted lemur.

Scientific reports, 12(1):5266.

How the presence of conspecifics affects scent mark deposition remains an understudied aspect of olfactory communication, even though scent marking occurs in different social contexts. Sex differences in scent-marking behaviour are common, and sex-specific effects of the audience could therefore be expected. We investigated sex differences in intra-group audience effects on anogenital scent marking in four groups of wild red-fronted lemurs (Eulemur rufifrons) by performing focal scent-marking observations. We observed a total of 327 events divided into 223 anogenital scent-marking events and 104 pass-by events (i.e. passage without scent marking). Using a combination of generalised linear mixed models and exponential random graph models, we found that scent marking in red-fronted lemurs is associated with some behavioural flexibility linked to the composition of the audience at the time of scent deposition. In particular, our study revealed sex differences in the audience effects, with males being overall more sensitive to their audience than females. Moreover, we show that these audience effects were dependent on the relative degree of social integration of the focal individual compared to that of individuals in the audience (difference in Composite Sociality Index) as well as the strength of the dyadic affiliative relationship (rank of Dyadic Composite Sociality Index within the group). The audience effects also varied as a function of the audience radius considered. Hence, we showed that scent marking in red-fronted lemurs is associated with some behavioural flexibility linked to the composition of the audience, ascribing red-fronted lemurs' social competence in this context.

RevDate: 2022-03-29

Radford JM, Chen D, Chernyshova AM, et al (2022)

Differential Selection on Caste-Associated Genes in a Subterranean Termite.

Insects, 13(3):.

Analyzing the information-rich content of RNA can help uncover genetic events associated with social insect castes or other social polymorphisms. Here, we exploit a series of cDNA libraries previously derived from whole-body tissue of different castes as well as from three behaviourally distinct populations of the Eastern subterranean termite Reticulitermes flavipes. We found that the number (~0.5 M) of single nucleotide variants (SNVs) was roughly equal between nymph, worker and soldier caste libraries, but dN/dS (ratio of nonsynonymous to synonymous substitutions) analysis suggested that some of these variants confer a caste-specific advantage. Specifically, the dN/dS ratio was high (~4.3) for genes expressed in the defensively specialized soldier caste, relative to genes expressed by other castes (~1.7-1.8) and regardless of the North American population (Toronto, Raleigh, Boston) from which the castes were sampled. The populations, meanwhile, did show a large difference in SNV count but not in the manner expected from known demographic and behavioural differences; the highly invasive unicolonial population from Toronto was not the least diverse and did not show any other unique substitution patterns, suggesting any past bottleneck associated with invasion or with current unicoloniality has become obscured at the RNA level. Our study raises two important hypotheses relevant to termite sociobiology. First, the positive selection (dN/dS > 1) inferred for soldier-biased genes is presumably indirect and of the type mediated through kin selection, and second, the behavioural changes that accompany some social insect urban invasions (i.e., 'unicoloniality') may be detached from the loss-of-diversity expected from invasion bottlenecks.

RevDate: 2022-04-29
CmpDate: 2022-04-29

Kaya-Zeeb S, Engelmayer L, Straßburger M, et al (2022)

Octopamine drives honeybee thermogenesis.

eLife, 11:.

In times of environmental change species have two options to survive: they either relocate to a new habitat or they adapt to the altered environment. Adaptation requires physiological plasticity and provides a selection benefit. In this regard, the Western honeybee (Apis mellifera) protrudes with its thermoregulatory capabilities, which enables a nearly worldwide distribution. Especially in the cold, shivering thermogenesis enables foraging as well as proper brood development and thus survival. In this study, we present octopamine signaling as a neurochemical prerequisite for honeybee thermogenesis: we were able to induce hypothermia by depleting octopamine in the flight muscles. Additionally, we could restore the ability to increase body temperature by administering octopamine. Thus, we conclude that octopamine signaling in the flight muscles is necessary for thermogenesis. Moreover, we show that these effects are mediated by β octopamine receptors. The significance of our results is highlighted by the fact the respective receptor genes underlie enormous selective pressure due to adaptation to cold climates. Finally, octopamine signaling in the service of thermogenesis might be a key strategy to survive in a changing environment.

RevDate: 2022-06-13
CmpDate: 2022-06-13

Milam EL (2022)

Landscapes of Time: Building Long-Term Perspectives in Animal Behavior.

Berichte zur Wissenschaftsgeschichte, 45(1-2):164-188.

In the 1960s, scientists fascinated by the behavior of free-living animals founded research projects that expanded into multi-generation investigations. This paper charts the history of three scientists' projects to uncover the varied reasons for investing in a "long-term" perspective when studying animal behavior: Kenneth Armitage's study of marmots in the Rocky Mountains, Jeanne Altmann's analysis of baboons in Kenya, and Timothy Hugh Clutton-Brock's studies (among others) of red deer on the island of Rhum and meerkats in the Kalahari. The desire to study the behavior of the same group of animals over extended periods of time, I argue, came from different methodological traditions - population biology, primatology, and sociobiology - even as each saw themselves as contributing to the legacy of ethology. As scientists embraced and combined these approaches, a small number of long-running behavioral ecology projects like these grew from short pilot projects into decades-long centers of intellectual gravity within behavioral ecology as a discipline. By attending to time as well as place, we can see how this long-term perspective was crucial to their success; they measured evolutionary changes over generations of animals and their data provided insights into how the animals they studied were adapting (or not) to changing local and global environmental factors.

RevDate: 2022-09-07
CmpDate: 2022-05-24

Hensgen R, Zittrell F, Pfeiffer K, et al (2022)

Performance of polarization-sensitive neurons of the locust central complex at different degrees of polarization.

Journal of comparative physiology. A, Neuroethology, sensory, neural, and behavioral physiology, 208(3):387-403.

The polarization pattern of the sky is exploited by many insects for spatial orientation and navigation. It derives from Rayleigh scattering in the atmosphere and depends directly on the position of the sun. In the insect brain, the central complex (CX) houses neurons tuned to the angle of polarization (AoP), that together constitute an internal compass for celestial navigation. Polarized light is not only characterized by the AoP, but also by the degree of polarization (DoP), which can be highly variable, depending on sky conditions. Under a clear sky, the DoP of polarized sky light may reach up to 0.75 but is usually much lower especially when light is scattered by clouds or haze. To investigate how the polarization-processing network of the CX copes with low DoPs, we recorded intracellularly from neurons of the locust CX at different stages of processing, while stimulating with light of different DoPs. Significant responses to polarized light occurred down to DoPs of 0.05 indicating reliable coding of the AoP even at unfavorable sky conditions. Moreover, we found that the activity of neurons at the CX input stage may be strongly influenced by nearly unpolarized light, while the activity of downstream neurons appears less affected.

RevDate: 2022-05-13
CmpDate: 2022-03-21

Rudolph K, Schneider D, Fichtel C, et al (2022)

Drivers of gut microbiome variation within and between groups of a wild Malagasy primate.

Microbiome, 10(1):28.

BACKGROUND: Various aspects of sociality can benefit individuals' health. The host social environment and its relative contributions to the host-microbiome relationship have emerged as key topics in microbial research. Yet, understanding the mechanisms that lead to structural variation in the social microbiome, the collective microbial metacommunity of an animal's social network, remains difficult since multiple processes operate simultaneously within and among animal social networks. Here, we examined the potential drivers of the convergence of the gut microbiome on multiple scales among and within seven neighbouring groups of wild Verreaux's sifakas (Propithecus verreauxi) - a folivorous primate of Madagascar.

RESULTS: Over four field seasons, we collected 519 faecal samples of 41 animals and determined gut communities via 16S and 18S rRNA gene amplicon analyses. First, we examined whether group members share more similar gut microbiota and if diet, home range overlap, or habitat similarity drive between-group variation in gut communities, accounting for seasonality. Next, we examined within-group variation in gut microbiota by examining the potential effects of social contact rates, male rank, and maternal relatedness. To explore the host intrinsic effects on the gut community structure, we investigated age, sex, faecal glucocorticoid metabolites, and female reproductive state. We found that group members share more similar gut microbiota and differ in alpha diversity, while none of the environmental predictors explained the patterns of between-group variation. Maternal relatedness played an important role in within-group microbial homogeneity and may also explain why adult group members shared the least similar gut microbiota. Also, dominant males differed in their bacterial composition from their group mates, which might be driven by rank-related differences in physiology and scent-marking behaviours. Links to sex, female reproductive state, or faecal glucocorticoid metabolites were not detected.

CONCLUSIONS: Environmental factors define the general set-up of population-specific gut microbiota, but intrinsic and social factors have a stronger impact on gut microbiome variation in this primate species. Video abstract.

RevDate: 2022-09-07
CmpDate: 2022-05-24

Zupanc GKH, Arikawa K, Helfrich-Förster C, et al (2022)

It's all about seeing and hearing: the Editors' and Readers' Choice Awards 2022.

Journal of comparative physiology. A, Neuroethology, sensory, neural, and behavioral physiology, 208(3):351-353.

This year marks the inauguration of the annual Editors' Choice Award and the Readers' Choice Award, each presented for outstanding original papers and review articles published in the Journal of Comparative Physiology A. The winners of the 2022 Editors' Choice Award were determined by vote of the Editorial Board for the most highly recommended papers published in Volume 207 in 2021. They are 'Visual discrimination and resolution in freshwater stingrays (Potamotrygon motoro)' by Daniel et al. (J Comp Physiol A 207, 43-58, 2021) in the Original Paper category; and 'Neurophysiology goes wild: from exploring sensory coding in sound proof rooms to natural environments' by Römer (J Comp Physiol A 207, 303-319, 2021) in the Review Article category. The 2022 Readers' Choice Award was based on access number of articles published in Volume 206 in 2020, to ensure at least 12-month online presence. It is given to Nicholas et al. for their original paper titled 'Visual motion sensitivity in descending neurons in the hoverfly' (J Comp Physiol A 206, 149-163, 2020); and to Schnaitmann et al. for their review article entitled 'Color vision in insects: insights from Drosophila' (J Comp Physiol A 206, 183-198, 2020).

RevDate: 2022-05-16
CmpDate: 2022-05-16

Grob R, Holland Cunz O, Grübel K, et al (2022)

Rotation of skylight polarization during learning walks is necessary to trigger neuronal plasticity in Cataglyphis ants.

Proceedings. Biological sciences, 289(1967):20212499.

Many animals use celestial cues for impressive navigational performances in challenging habitats. Since the position of the sun and associated skylight cues change throughout the day and season, it is crucial to correct for these changes. Cataglyphis desert ants possess a time-compensated skylight compass allowing them to navigate back to their nest using the shortest way possible. The ants have to learn the sun's daily course (solar ephemeris) during initial learning walks (LW) before foraging. This learning phase is associated with substantial structural changes in visual neuronal circuits of the ant's brain. Here, we test whether the rotation of skylight polarization during LWs is the necessary cue to induce learning-dependent rewiring in synaptic circuits in high-order integration centres of the ant brain. Our results show that structural neuronal changes in the central complex and mushroom bodies are triggered only when LWs were performed under a rotating skylight polarization pattern. By contrast, when naive ants did not perform LWs, but were exposed to skylight cues, plasticity was restricted to light spectrum-dependent changes in synaptic complexes of the lateral complex. The results identify sky-compass cues triggering learning-dependent versus -independent neuronal plasticity during the behavioural transition from interior workers to outdoor foragers.

RevDate: 2022-01-28

Schilcher F, Hilsmann L, Rauscher L, et al (2021)

In Vitro Rearing Changes Social Task Performance and Physiology in Honeybees.

Insects, 13(1):.

In vitro rearing of honeybee larvae is an established method that enables exact control and monitoring of developmental factors and allows controlled application of pesticides or pathogens. However, only a few studies have investigated how the rearing method itself affects the behavior of the resulting adult honeybees. We raised honeybees in vitro according to a standardized protocol: marking the emerging honeybees individually and inserting them into established colonies. Subsequently, we investigated the behavioral performance of nurse bees and foragers and quantified the physiological factors underlying the social organization. Adult honeybees raised in vitro differed from naturally reared honeybees in their probability of performing social tasks. Further, in vitro-reared bees foraged for a shorter duration in their life and performed fewer foraging trips. Nursing behavior appeared to be unaffected by rearing condition. Weight was also unaffected by rearing condition. Interestingly, juvenile hormone titers, which normally increase strongly around the time when a honeybee becomes a forager, were significantly lower in three- and four-week-old in vitro bees. The effects of the rearing environment on individual sucrose responsiveness and lipid levels were rather minor. These data suggest that larval rearing conditions can affect the task performance and physiology of adult bees despite equal weight, pointing to an important role of the colony environment for these factors. Our observations of behavior and metabolic pathways offer important novel insight into how the rearing environment affects adult honeybees.

RevDate: 2021-12-26

Iacob GM, Craioveanu C, Hula V, et al (2021)

Improving the Knowledge on Distribution, Food Preferences and DNA Barcoding of Natura 2000 Protected Species Paracossulus thrips (Lepidoptera, Cossidae) in Romania.

Insects, 12(12):.

Paracossulus thrips (Lepidoptera, Cossidae) is one of the locally distributed and endangered species. In Europe, it is also one of the few protected moth species, through Annexes II and IV of the Council Directive 92/43/EEC, Annex II of the Bern Convention. To date, little is known about the biology and ecology of this species. Our study was conducted in Transylvania, Romania. Romania hosts some of the strongest populations of the species in the European region. As part of the study, we conducted field observations, vegetation analyses, and genetic analyses. In our paper, we show the habitat types where we encounter P. thrips in Transylvania and confirm Phlomis tuberosa as a host plant. Furthermore, a piece of important information for habitat conservation is given. In this paper, we present the eggs and larvae of P. thrips, the first DNA barcoding sequences, and four new populations of P. thrips in Romania. Our study provides baseline knowledge about the biology and ecology of P. thrips, which is important for conservation and establishing management measures.

RevDate: 2022-05-13
CmpDate: 2022-04-05

Grittner R, Baird E, A Stöckl (2022)

Spatial tuning of translational optic flow responses in hawkmoths of varying body size.

Journal of comparative physiology. A, Neuroethology, sensory, neural, and behavioral physiology, 208(2):279-296.

To safely navigate their environment, flying insects rely on visual cues, such as optic flow. Which cues insects can extract from their environment depends closely on the spatial and temporal response properties of their visual system. These in turn can vary between individuals that differ in body size. How optic flow-based flight control depends on the spatial structure of visual cues, and how this relationship scales with body size, has previously been investigated in insects with apposition compound eyes. Here, we characterised the visual flight control response limits and their relationship to body size in an insect with superposition compound eyes: the hummingbird hawkmoth Macroglossum stellatarum. We used the hawkmoths' centring response in a flight tunnel as a readout for their reception of translational optic flow stimuli of different spatial frequencies. We show that their responses cut off at different spatial frequencies when translational optic flow was presented on either one, or both tunnel walls. Combined with differences in flight speed, this suggests that their flight control was primarily limited by their temporal rather than spatial resolution. We also observed strong individual differences in flight performance, but no correlation between the spatial response cutoffs and body or eye size.

RevDate: 2022-04-11
CmpDate: 2022-04-11

Pisokas I, Rössler W, Webb B, et al (2022)

Anesthesia disrupts distance, but not direction, of path integration memory.

Current biology : CB, 32(2):445-452.e4.

Solitary foraging insects, such as ants, maintain an estimate of the direction and distance to their starting location as they move away from it, in a process known as path integration. This estimate, commonly known as the "home vector," is updated continuously as the ant moves1-4 and is reset as soon as it enters its nest,5 yet ants prevented from returning to their nest can still use their home vector when released several hours later.6,7 This conjunction of fast update and long persistence of the home vector memory does not directly map to existing accounts of short-, mid-, and long-term memory;2,8-12 hence, the substrate of this memory remains unknown. Chill-coma anesthesia13-15 has previously been shown to affect associative memory retention in fruit flies14,16 and honeybees.9,17,18 We investigate the nature of path integration memory by anesthetizing ants after they have accumulated home vector information and testing if the memory persists on recovery. We show that after anesthesia the memory of the distance ants have traveled is degraded, but the memory of the direction is retained. We also show that this is consistent with models of path integration that maintain the memory in a redundant Cartesian coordinate system and with the hypothesis that chill-coma produces a proportional reduction of the memory, rather than a subtractive reduction or increase of noise. The observed effect is not compatible with a memory based on recurrent circuit activity and points toward an activity-dependent molecular process as the basis of path integration memory.

RevDate: 2021-12-03

Bollazzi M, Römer D, F Roces (2021)

Carbon dioxide levels and ventilation in Acromyrmex nests: significance and evolution of architectural innovations in leaf-cutting ants.

Royal Society open science, 8(11):210907.

Leaf-cutting ant colonies largely differ in size, yet all consume O2 and produce CO2 in large amounts because of their underground fungus gardens. We have shown that in the Acromyrmex genus, three basic nest morphologies occur, and investigated the effects of architectural innovations on nest ventilation. We recognized (i) serial nests, similar to the ancestral type of the sister genus Trachymyrmex, with chambers excavated along a vertical tunnel connecting to the outside via a single opening, (ii) shallow nests, with one/few chambers extending shallowly with multiple connections to the outside, and (iii) thatched nests, with an above-ground fungus garden covered with plant material. Ventilation in shallow and thatched nests, but not in serial nests, occurred via wind-induced flows and thermal convection. CO2 concentrations were below the values known to affect the respiration of the symbiotic fungus, indicating that shallow and thatched nests are not constrained by harmful CO2 levels. Serial nests may be constrained depending on the soil CO2 levels. We suggest that in Acromyrmex, selective pressures acting on temperature and humidity control led to nesting habits closer to or above the soil surface and to the evolution of architectural innovations that improved gas exchanges.

RevDate: 2022-04-01
CmpDate: 2022-03-31

Henke-von der Malsburg J, Kappeler PM, C Fichtel (2021)

Linking cognition to ecology in wild sympatric mouse lemur species.

Proceedings. Biological sciences, 288(1963):20211728.

Cognitive abilities covary with both social and ecological factors across animal taxa. Ecological generalists have been attributed with enhanced cognitive abilities, but which specific ecological factors may have shaped the evolution of which specific cognitive abilities remains poorly known. To explore these links, we applied a cognitive test battery (two personality, ten cognitive tests; n = 1104 tests) to wild individuals of two sympatric mouse lemur species (n = 120 Microcebus murinus, n = 34 M. berthae) varying in ecological adaptations but sharing key features of their social systems. The habitat and dietary generalist grey mouse lemurs were more innovative and exhibited better spatial learning abilities; a cognitive advantage in responding adaptively to dynamic environmental conditions. The more specialized Madame Berthe's mouse lemurs were faster in learning associative reward contingencies, providing relative advantages in stable environmental conditions. Hence, our study revealed key cognitive correlates of ecological adaptations and indicates potential cognitive constraints of specialists that may help explain why they face a greater extinction risk in the context of current environmental changes.

RevDate: 2022-07-16
CmpDate: 2022-05-17

Eckert J, Bohn M, J Spaethe (2022)

Does quantity matter to a stingless bee?.

Animal cognition, 25(3):617-629.

Quantitative information is omnipresent in the world and a wide range of species has been shown to use quantities to optimize their decisions. While most studies have focused on vertebrates, a growing body of research demonstrates that also insects such as honeybees possess basic quantitative abilities that might aid them in finding profitable flower patches. However, it remains unclear if for insects, quantity is a salient feature relative to other stimulus dimensions, or if it is only used as a "last resort" strategy in case other stimulus dimensions are inconclusive. Here, we tested the stingless bee Trigona fuscipennis, a species representative of a vastly understudied group of tropical pollinators, in a quantity discrimination task. In four experiments, we trained wild, free-flying bees on stimuli that depicted either one or four elements. Subsequently, bees were confronted with a choice between stimuli that matched the training stimulus either in terms of quantity or another stimulus dimension. We found that bees were able to discriminate between the two quantities, but performance differed depending on which quantity was rewarded. Furthermore, quantity was more salient than was shape. However, quantity did not measurably influence the bees' decisions when contrasted with color or surface area. Our results demonstrate that just as honeybees, small-brained stingless bees also possess basic quantitative abilities. Moreover, invertebrate pollinators seem to utilize quantity not only as "last resort" but as a salient stimulus dimension. Our study contributes to the growing body of knowledge on quantitative cognition in invertebrate species and adds to our understanding of the evolution of numerical cognition.

RevDate: 2022-04-27
CmpDate: 2022-04-27

Fleischmann PN, Grob R, W Rössler (2022)

Magnetosensation during re-learning walks in desert ants (Cataglyphis nodus).

Journal of comparative physiology. A, Neuroethology, sensory, neural, and behavioral physiology, 208(1):125-133.

At the beginning of their foraging careers, Cataglyphis desert ants calibrate their compass systems and learn the visual panorama surrounding the nest entrance. For that, they perform well-structured initial learning walks. During rotational body movements (pirouettes), naïve ants (novices) gaze back to the nest entrance to memorize their way back to the nest. To align their gaze directions, they rely on the geomagnetic field as a compass cue. In contrast, experienced ants (foragers) use celestial compass cues for path integration during food search. If the panorama at the nest entrance is changed, foragers perform re-learning walks prior to heading out on new foraging excursions. Here, we show that initial learning walks and re-learning walks are structurally different. During re-learning walks, foragers circle around the nest entrance before leaving the nest area to search for food. During pirouettes, they do not gaze back to the nest entrance. In addition, foragers do not use the magnetic field as a compass cue to align their gaze directions during re-learning walk pirouettes. Nevertheless, magnetic alterations during re-learning walks under manipulated panoramic conditions induce changes in nest-directed views indicating that foragers are still magnetosensitive in a cue conflict situation.

RevDate: 2021-12-28
CmpDate: 2021-12-28

Madeo D, Salvatore S, Mannarini T, et al (2021)

Modeling pluralism and self-regulation explains the emergence of cooperation in networked societies.

Scientific reports, 11(1):19226.

Understanding the dynamics of cooperative behavior of individuals in complex societies represents a fundamental research question which puzzles scientists working in heterogeneous fields. Many studies have been developed using the unitary agent assumption, which embeds the idea that when making decisions, individuals share the same socio-cultural parameters. In this paper, we propose the ECHO-EGN model, based on Evolutionary Game Theory, which relaxes this strong assumption by considering the heterogeneity of three fundamental socio-cultural aspects ruling the behavior of groups of people: the propensity to be more cooperative with members of the same group (Endogamic cooperation), the propensity to cooperate with the public domain (Civicness) and the propensity to prefer connections with members of the same group (Homophily). The ECHO-EGN model is shown to have high performance in describing real world behavior of interacting individuals living in complex environments. Extensive numerical experiments allowing the comparison of real data and model simulations confirmed that the introduction of the above mechanisms enhances the realism in the modelling of cooperation dynamics. Additionally, theoretical findings allow us to conclude that endogamic cooperation may limit significantly the emergence of cooperation.

RevDate: 2022-01-11
CmpDate: 2022-01-11

Schilcher F, Thamm M, Strube-Bloss M, et al (2021)

Opposing Actions of Octopamine and Tyramine on Honeybee Vision.

Biomolecules, 11(9):.

The biogenic amines octopamine and tyramine are important neurotransmitters in insects and other protostomes. They play a pivotal role in the sensory responses, learning and memory and social organisation of honeybees. Generally, octopamine and tyramine are believed to fulfil similar roles as their deuterostome counterparts epinephrine and norepinephrine. In some cases opposing functions of both amines have been observed. In this study, we examined the functions of tyramine and octopamine in honeybee responses to light. As a first step, electroretinography was used to analyse the effect of both amines on sensory sensitivity at the photoreceptor level. Here, the maximum receptor response was increased by octopamine and decreased by tyramine. As a second step, phototaxis experiments were performed to quantify the behavioural responses to light following treatment with either amine. Octopamine increased the walking speed towards different light sources while tyramine decreased it. This was independent of locomotor activity. Our results indicate that tyramine and octopamine act as functional opposites in processing responses to light.

RevDate: 2021-09-30

Scheiner R, Lim K, Meixner MD, et al (2021)

Comparing the Appetitive Learning Performance of Six European Honeybee Subspecies in a Common Apiary.

Insects, 12(9):.

The Western honeybee (Apis mellifera L.) is one of the most widespread insects with numerous subspecies in its native range. How far adaptation to local habitats has affected the cognitive skills of the different subspecies is an intriguing question that we investigate in this study. Naturally mated queens of the following five subspecies from different parts of Europe were transferred to Southern Germany: A. m. iberiensis from Portugal, A. m. mellifera from Belgium, A. m. macedonica from Greece, A. m. ligustica from Italy, and A. m. ruttneri from Malta. We also included the local subspecies A. m. carnica in our study. New colonies were built up in a common apiary where the respective queens were introduced. Worker offspring from the different subspecies were compared in classical olfactory learning performance using the proboscis extension response. Prior to conditioning, we measured individual sucrose responsiveness to investigate whether possible differences in learning performances were due to differential responsiveness to the sugar water reward. Most subspecies did not differ in their appetitive learning performance. However, foragers of the Iberian honeybee, A. m. iberiensis, performed significantly more poorly, despite having a similar sucrose responsiveness. We discuss possible causes for the poor performance of the Iberian honeybees, which may have been shaped by adaptation to the local habitat.

RevDate: 2022-09-10
CmpDate: 2021-10-29

Püffel F, Pouget A, Liu X, et al (2021)

Morphological determinants of bite force capacity in insects: a biomechanical analysis of polymorphic leaf-cutter ants.

Journal of the Royal Society, Interface, 18(182):20210424.

The extraordinary success of social insects is partially based on division of labour, i.e. individuals exclusively or preferentially perform specific tasks. Task preference may correlate with morphological adaptations so implying task specialization, but the extent of such specialization can be difficult to determine. Here, we demonstrate how the physical foundation of some tasks can be leveraged to quantitatively link morphology and performance. We study the allometry of bite force capacity in Atta vollenweideri leaf-cutter ants, polymorphic insects in which the mechanical processing of plant material is a key aspect of the behavioural portfolio. Through a morphometric analysis of tomographic scans, we show that the bite force capacity of the heaviest colony workers is twice as large as predicted by isometry. This disproportionate 'boost' is predominantly achieved through increased investment in muscle volume; geometrical parameters such as mechanical advantage, fibre length or pennation angle are likely constrained by the need to maintain a constant mandibular opening range. We analyse this preference for an increase in size-specific muscle volume and the adaptations in internal and external head anatomy required to accommodate it with simple geometric and physical models, so providing a quantitative understanding of the functional anatomy of the musculoskeletal bite apparatus in insects.

RevDate: 2022-03-25
CmpDate: 2022-03-25

Scherz P (2022)

Life as an Intelligence Test: Intelligence, Education, and Behavioral Genetics.

Culture, medicine and psychiatry, 46(1):59-75.

Using the large datasets available with new gene sequencing and biobank projects, behavioral geneticists are developing tools that attempt to predict individual intelligence based on genetics. These predictive tools are meant to enable a 'precision education' that will transform society. These technological developments have not changed the fundamental aims of a program with a long history. Behavioral genetics is continuous with previous attempts to match personal characteristics to heredity, such as sociobiology and evolutionary psychology, and threatens racial and other forms of bias. From these older paradigms, it inherits an understanding of intelligence as informational processing shaped by mechanistic and computational metaphors as well as a view of society and education organized around competition. Because of these influences, these models misdescribe fundamental aspects of human engagement with the world and disregard other concepts of intelligence, which creates problems for the precision education that researchers hope to construct using genetic knowledge.

RevDate: 2021-10-19
CmpDate: 2021-10-19

Heinze S, El Jundi B, Berg BG, et al (2021)

A unified platform to manage, share, and archive morphological and functional data in insect neuroscience.

eLife, 10:.

Insect neuroscience generates vast amounts of highly diverse data, of which only a small fraction are findable, accessible and reusable. To promote an open data culture, we have therefore developed the InsectBrainDatabase (IBdb), a free online platform for insect neuroanatomical and functional data. The IBdb facilitates biological insight by enabling effective cross-species comparisons, by linking neural structure with function, and by serving as general information hub for insect neuroscience. The IBdb allows users to not only effectively locate and visualize data, but to make them widely available for easy, automated reuse via an application programming interface. A unique private mode of the database expands the IBdb functionality beyond public data deposition, additionally providing the means for managing, visualizing, and sharing of unpublished data. This dual function creates an incentive for data contribution early in data management workflows and eliminates the additional effort normally associated with publicly depositing research data.

RevDate: 2022-07-31

Kavanagh E, Street SE, Angwela FO, et al (2021)

Dominance style is a key predictor of vocal use and evolution across nonhuman primates.

Royal Society open science, 8(7):210873.

Animal communication has long been thought to be subject to pressures and constraints associated with social relationships. However, our understanding of how the nature and quality of social relationships relates to the use and evolution of communication is limited by a lack of directly comparable methods across multiple levels of analysis. Here, we analysed observational data from 111 wild groups belonging to 26 non-human primate species, to test how vocal communication relates to dominance style (the strictness with which a dominance hierarchy is enforced, ranging from 'despotic' to 'tolerant'). At the individual-level, we found that dominant individuals who were more tolerant vocalized at a higher rate than their despotic counterparts. This indicates that tolerance within a relationship may place pressure on the dominant partner to communicate more during social interactions. At the species-level, however, despotic species exhibited a larger repertoire of hierarchy-related vocalizations than their tolerant counterparts. Findings suggest primate signals are used and evolve in tandem with the nature of interactions that characterize individuals' social relationships.

RevDate: 2021-11-03
CmpDate: 2021-11-03

Guignard Q, Spaethe J, Slippers B, et al (2021)

Evidence for UV-green dichromacy in the basal hymenopteran Sirex noctilio (Siricidae).

Scientific reports, 11(1):15601.

A precondition for colour vision is the presence of at least two spectral types of photoreceptors in the eye. The order Hymenoptera is traditionally divided into the Apocrita (ants, bees, wasps) and the Symphyta (sawflies, woodwasps, horntails). Most apocritan species possess three different photoreceptor types. In contrast, physiological studies in the Symphyta have reported one to four photoreceptor types. To better understand the evolution of photoreceptor diversity in the Hymenoptera, we studied the Symphyta Sirex noctilio, which belongs to the superfamily Siricoidea, a closely related group of the Apocrita suborder. Our aim was to (i) identify the photoreceptor types of the compound eye by electroretinography (ERG), (ii) characterise the visual opsin genes of S. noctilio by genomic comparisons and phylogenetic analyses and (iii) analyse opsin mRNA expression. ERG measurements revealed two photoreceptor types in the compound eye, maximally sensitive to 527 and 364 nm. In addition, we identified three opsins in the genome, homologous to the hymenopteran green or long-wavelength sensitive (LW) LW1, LW2 and ultra-violet sensitive (UV) opsin genes. The LW1 and UV opsins were found to be expressed in the compound eyes, and LW2 and UV opsins in the ocelli. The lack of a blue or short-wavelength sensitive (SW) homologous opsin gene and a corresponding receptor suggests that S. noctilio is a UV-green dichromate.

RevDate: 2022-03-24
CmpDate: 2022-03-24

Grob R, Heinig N, Grübel K, et al (2021)

Sex-specific and caste-specific brain adaptations related to spatial orientation in Cataglyphis ants.

The Journal of comparative neurology, 529(18):3882-3892.

Cataglyphis desert ants are charismatic central place foragers. After long-ranging foraging trips, individual workers navigate back to their nest relying mostly on visual cues. The reproductive caste faces other orientation challenges, i.e. mate finding and colony foundation. Here we compare brain structures involved in spatial orientation of Cataglyphis nodus males, gynes, and foragers by quantifying relative neuropil volumes associated with two visual pathways, and numbers and volumes of antennal lobe (AL) olfactory glomeruli. Furthermore, we determined absolute numbers of synaptic complexes in visual and olfactory regions of the mushroom bodies (MB) and a major relay station of the sky-compass pathway to the central complex (CX). Both female castes possess enlarged brain centers for sensory integration, learning, and memory, reflected in voluminous MBs containing about twice the numbers of synaptic complexes compared with males. Overall, male brains are smaller compared with both female castes, but the relative volumes of the optic lobes and CX are enlarged indicating the importance of visual guidance during innate behaviors. Male ALs contain greatly enlarged glomeruli, presumably involved in sex-pheromone detection. Adaptations at both the neuropil and synaptic levels clearly reflect differences in sex-specific and caste-specific demands for sensory processing and behavioral plasticity underlying spatial orientation.

RevDate: 2021-10-25
CmpDate: 2021-10-25

Thamm M, Wagler K, Brockmann A, et al (2021)

Tyramine 1 Receptor Distribution in the Brain of Corbiculate Bees Points to a Conserved Function.

Brain, behavior and evolution, 96(1):13-25.

Sucrose represents an important carbohydrate source for most bee species. In the Western honeybee (Apis mellifera) it was shown that individual sucrose responsiveness correlates with the task performed in the colony, supporting the response threshold theory which states that individuals with the lowest threshold for a task-associated stimuli will perform the associated task. Tyramine was shown to modulate sucrose responsiveness, most likely via the tyramine 1 receptor. This receptor is located in brain areas important for the processing of gustatory stimuli. We asked whether the spatial expression pattern of the tyramine 1 receptor is a unique adaptation of honeybees or if its expression represents a conserved trait. Using a specific tyramine receptor 1 antibody, we compared the spatial expression of this receptor in the brain of different corbiculate bee species, including eusocial honeybees, bumblebees, stingless bees, and the solitary bee Osmia bicornis as an outgroup. We found a similar labeling pattern in the mushroom bodies, the central complex, the dorsal lobe, and the gnathal ganglia, indicating a conserved receptor expression. With respect to sucrose responsiveness this result is of special importance. We assume that the tyramine 1 receptor expression in these neuropiles provides the basis for modulation of sucrose responsiveness. Furthermore, the tyramine 1 receptor expression seems to be independent of size, as labeling is similar in bee species that differ greatly in their body size. However, the situation in the optic lobes appears to be different. Here, the lobula of stingless bees is clearly labeled by the tyramine receptor 1 antibody, whereas this labeling is absent in other species. This indicates that the regulation of this receptor is different in the optic lobes, while its function in this neuropile remains unclear.

RevDate: 2021-07-10

Uiuiu P, Lațiu C, Păpuc T, et al (2021)

Multi-Approach Assessment for Stress Evaluation in Rainbow Trout Females, Oncorhynchus mykiss (Walbaum, 1792) from Three Different Farms during the Summer Season.

Animals : an open access journal from MDPI, 11(6):.

Blood biochemistry parameters are valuable tools for monitoring fish health. Their baseline values are still undefined for a multitude of farmed fish species. In this study, changes in the blood profile of rainbow trout females (Oncorhynchus mykiss) from three farms were investigated using different biomarkers during the summer season. In the given context, the main water physicochemical parameters were investigated and twelve biochemical parameters were measured from blood samples of rainbow trout reared in the Fiad, Șoimul de Jos, and Strâmba farms. We selected these farms because the genetic background of the rainbow trout is the same, with all studied specimens coming from the Fiad farm, which has an incubation station. Forty-five samples were collected monthly (May to August) throughout summer to observe the changes in the blood profile of rainbow trout. Principal component analysis showed a clear separation both among the studied farms and months. Furthermore, significant correlations (p < 0.05) between the majority of the biochemical parameters were found, indicating that the environmental parameters can influence several blood parameters at the same time. The present study provides several useful norms for assessing the welfare of rainbow trout, indicating that the relationships among different parameters are important factors in interpreting the blood biochemical profiles.

RevDate: 2022-05-31
CmpDate: 2022-02-08

Rother L, Kraft N, Smith DB, et al (2021)

A micro-CT-based standard brain atlas of the bumblebee.

Cell and tissue research, 386(1):29-45.

In recent years, bumblebees have become a prominent insect model organism for a variety of biological disciplines, particularly to investigate learning behaviors as well as visual performance. Understanding these behaviors and their underlying neurobiological principles requires a clear understanding of brain anatomy. Furthermore, to be able to compare neuronal branching patterns across individuals, a common framework is required, which has led to the development of 3D standard brain atlases in most of the neurobiological insect model species. Yet, no bumblebee 3D standard brain atlas has been generated. Here we present a brain atlas for the buff-tailed bumblebee Bombus terrestris using micro-computed tomography (micro-CT) scans as a source for the raw data sets, rather than traditional confocal microscopy, to produce the first ever micro-CT-based insect brain atlas. We illustrate the advantages of the micro-CT technique, namely, identical native resolution in the three cardinal planes and 3D structure being better preserved. Our Bombus terrestris brain atlas consists of 30 neuropils reconstructed from ten individual worker bees, with micro-CT allowing us to segment neuropils completely intact, including the lamina, which is a tissue structure often damaged when dissecting for immunolabeling. Our brain atlas can serve as a platform to facilitate future neuroscience studies in bumblebees and illustrates the advantages of micro-CT for specific applications in insect neuroanatomy.

RevDate: 2021-10-25
CmpDate: 2021-10-25

Philippon J, Serrano-Martínez E, C Poirotte (2021)

Environmental and individual determinants of fecal avoidance in semi-free ranging woolly monkeys (Lagothrix lagotricha poeppigii).

American journal of physical anthropology, 176(4):614-624.

OBJECTIVES: Parasite selection pressures have driven the evolution of numerous behavioral defenses in host species, but recent studies revealed individual variation in their expression. As little is known about the factors causing heterogeneity among individuals in infection-avoidance behaviors, we investigated in woolly monkeys (Lagothrix lagotricha poeppigii) the influence of several environmental and individual characteristics on the tendency to avoid food contaminated by soil and by their own and conspecifics' feces.

MATERIALS AND METHODS: We conducted feeding tests on 40 semi-free ranging individuals rescued from the pet trade. Using generalized linear mixed models, we investigated the effect of season, sex, age, dominance rank, and exposure to non-natural living conditions on feeding decisions.

RESULTS: Woolly monkeys did not avoid soil-contaminated food and equally avoided food contaminated by their own and conspecifics' feces. Individuals varied greatly in their level of fecal avoidance. Only females exhibited strong avoidance of fecally contaminated food, but adapted their behavior to food availability, highlighting the trade-off between nutritional intake and parasite avoidance. Additionally, low-ranking females, less competitive over food resources, exhibited lower avoidance than dominant ones. Juveniles were more cautious than adults, possibly to compensate for a higher parasite susceptibility. Finally, we reported an unknown effect of exposure to non-natural living conditions on behavioral defenses, as animals kept as household pets for an extended period apparently lost their ability to avoid fecally contaminated food.

CONCLUSION: We argue that striving to understand variation in infection-avoidance behaviors in natural populations is crucial to predict disease spread and inform conservation policies.

RevDate: 2021-12-07
CmpDate: 2021-06-28

Colchero F, Aburto JM, Archie EA, et al (2021)

The long lives of primates and the 'invariant rate of ageing' hypothesis.

Nature communications, 12(1):3666.

Is it possible to slow the rate of ageing, or do biological constraints limit its plasticity? We test the 'invariant rate of ageing' hypothesis, which posits that the rate of ageing is relatively fixed within species, with a collection of 39 human and nonhuman primate datasets across seven genera. We first recapitulate, in nonhuman primates, the highly regular relationship between life expectancy and lifespan equality seen in humans. We next demonstrate that variation in the rate of ageing within genera is orders of magnitude smaller than variation in pre-adult and age-independent mortality. Finally, we demonstrate that changes in the rate of ageing, but not other mortality parameters, produce striking, species-atypical changes in mortality patterns. Our results support the invariant rate of ageing hypothesis, implying biological constraints on how much the human rate of ageing can be slowed.

RevDate: 2022-02-18

Ariansen AMS (2021)

"Quiet is the New Loud": The Biosociology Debate's Absent Voices.

The American sociologist, 52(3):477-504.

In 2000, a controversial article about hormones and gender roles was published to stimulate debate about whether and how biological knowledge should be integrated in sociological research. Two decades later, this so-called biosociology debate is more relevant than ever, as biological knowledge has become widespread across societies and scientific disciplines. Hence, we as sociologists are regularly confronted with biological explanations that challenge our own explanations. Whether this happens in the scientific arena, the classroom, media, or even at social events, these situations often force us, individually, to take a stance on whether to meet such explanations with dialogue or opposition. One could therefore expect that sociologists have an interest in discussing these issues with their peers, but their lack of participation in the biosociology debate suggests otherwise. This paper explores possible reasons for this absence and how sociologists' views on biosociology are influenced by key agents - sociological associations and journals. Smith's "A Sacred project of American Sociology", and Scott's "A Sociology of Nothing" served as theoretical tools in the paper. A qualitative content analysis of presidential addresses of four sociological associations was conducted. The analyses suggest that sociologist avoid biosociology for widely different reasons, including fear that biosociology legitimizes oppression. This avoidance is probably reinforced by the leftish politization of the sociological discipline and the rightish politization of society. Overcoming obstacles to engagement in biosociology is required to safeguard the scientific integrity of sociology and enable sociologists to provide relevant contributions to research on the Covid-19 pandemic and climate change.

RevDate: 2021-06-05

Dinter K, Heistermann M, Kappeler PM, et al (2021)

Life on the edge: behavioural and physiological responses of Verreaux's sifakas (Propithecus verreauxi) to forest edges.

Primate biology, 8(1):1-13.

Forest edges change micro-environmental conditions, thereby affecting the ecology of many forest-dwelling species. Understanding such edge effects is particularly important for Malagasy primates because many of them live in highly fragmented forests today. The aim of our study was to assess the influence of forest edge effects on activity budgets, feeding ecology, and stress hormone output (measured as faecal glucocorticoid metabolite - fGCM - levels) in wild Verreaux's sifakas (Propithecus verreauxi), a group living, arboreal lemur. We observed five habituated groups: three living in the forest interior and two at an established forest edge. There was no difference in average daily temperatures between edge and interior habitats; however, within the edge site, the average daily temperature incrementally increased over 450 m from the forest edge towards the interior forest of the edge habitat, and the population density was lower at the edge site. Activity budgets differed between groups living in the two microhabitats, with individuals living near the edge spending more time travelling and less time feeding. Groups living near the edge also tended to have smaller home ranges and core areas than groups in the forest interior. In addition, edge groups had elevated average fGCM concentrations, and birth rates were lower for females living in the edge habitat. Combined with lower levels of fruit consumption at the edge, these results suggest that nutritional stress might be a limiting factor for Verreaux's sifakas when living near a forest edge. Hence, Verreaux's sifakas appear to be sensitive to microhabitat characteristics linked to forest edges; a result with implications for the conservation of this critically endangered lemurid species.

RevDate: 2022-02-09
CmpDate: 2022-02-09

Habenstein J, Thamm M, W Rössler (2021)

Neuropeptides as potential modulators of behavioral transitions in the ant Cataglyphis nodus.

The Journal of comparative neurology, 529(12):3155-3170.

Age-related behavioral plasticity is a major prerequisite for the ecological success of insect societies. Although ecological aspects of behavioral flexibility have been targeted in many studies, the underlying intrinsic mechanisms controlling the diverse changes in behavior along the individual life history of social insects are not completely understood. Recently, the neuropeptides allatostatin-A, corazonin, and tachykinin have been associated with the regulation of behavioral transitions in social insects. Here, we investigated changes in brain localization and expression of these neuropeptides following major behavioral transitions in Cataglyphis nodus ants. Our immunohistochemical analyses in the brain revealed that the overall branching pattern of neurons immunoreactive (ir) for the three neuropeptides is largely independent of the behavioral stages. Numerous allatostatin-A- and tachykinin-ir neurons innervate primary sensory neuropils and high-order integration centers of the brain. In contrast, the number of corazonergic neurons is restricted to only four neurons per brain hemisphere with cell bodies located in the pars lateralis and axons extending to the medial protocerebrum and the retrocerebral complex. Most interestingly, the cell-body volumes of these neurons are significantly increased in foragers compared to freshly eclosed ants and interior workers. Quantification of mRNA expression levels revealed a stage-related change in the expression of allatostatin-A and corazonin mRNA in the brain. Given the presence of the neuropeptides in major control centers of the brain and the neurohemal organs, these mRNA-changes strongly suggest an important modulatory role of both neuropeptides in the behavioral maturation of Cataglyphis ants.

RevDate: 2021-07-25

Fouks B, Brand P, Nguyen HN, et al (2021)

The genomic basis of evolutionary differentiation among honey bees.

Genome research [Epub ahead of print].

In contrast to the western honey bee, Apis mellifera, other honey bee species have been largely neglected despite their importance and diversity. The genetic basis of the evolutionary diversification of honey bees remains largely unknown. Here, we provide a genome-wide comparison of three honey bee species, each representing one of the three subgenera of honey bees, namely the dwarf (Apis florea), giant (A. dorsata), and cavity-nesting (A. mellifera) honey bees with bumblebees as an outgroup. Our analyses resolve the phylogeny of honey bees with the dwarf honey bees diverging first. We find that evolution of increased eusocial complexity in Apis proceeds via increases in the complexity of gene regulation, which is in agreement with previous studies. However, this process seems to be related to pathways other than transcriptional control. Positive selection patterns across Apis reveal a trade-off between maintaining genome stability and generating genetic diversity, with a rapidly evolving piRNA pathway leading to genomes depleted of transposable elements, and a rapidly evolving DNA repair pathway associated with high recombination rates in all Apis species. Diversification within Apis is accompanied by positive selection in several genes whose putative functions present candidate mechanisms for lineage-specific adaptations, such as migration, immunity, and nesting behavior.

RevDate: 2022-04-17
CmpDate: 2021-11-09

Crabtree SA, White DA, Bradshaw CJA, et al (2021)

Landscape rules predict optimal superhighways for the first peopling of Sahul.

Nature human behaviour, 5(10):1303-1313.

Archaeological data and demographic modelling suggest that the peopling of Sahul required substantial populations, occurred rapidly within a few thousand years and encompassed environments ranging from hyper-arid deserts to temperate uplands and tropical rainforests. How this migration occurred and how humans responded to the physical environments they encountered have, however, remained largely speculative. By constructing a high-resolution digital elevation model for Sahul and coupling it with fine-scale viewshed analysis of landscape prominence, least-cost pedestrian travel modelling and high-performance computing, we create over 125 billion potential migratory pathways, whereby the most parsimonious routes traversed emerge. Our analysis revealed several major pathways-superhighways-transecting the continent, that we evaluated using archaeological data. These results suggest that the earliest Australian ancestors adopted a set of fundamental rules shaped by physiological capacity, attraction to visually prominent landscape features and freshwater distribution to maximize survival, even without previous experience of the landscapes they encountered.

RevDate: 2021-05-18

Khambhati K, Patel J, Saxena V, et al (2021)

Gene Regulation of Biofilm-Associated Functional Amyloids.

Pathogens (Basel, Switzerland), 10(4):.

Biofilms are bacterial communities encased in a rigid yet dynamic extracellular matrix. The sociobiology of bacterial communities within a biofilm is astonishing, with environmental factors playing a crucial role in determining the switch from planktonic to a sessile form of life. The mechanism of biofilm biogenesis is an intriguingly complex phenomenon governed by the tight regulation of expression of various biofilm-matrix components. One of the major constituents of the biofilm matrix is proteinaceous polymers called amyloids. Since the discovery, the significance of biofilm-associated amyloids in adhesion, aggregation, protection, and infection development has been much appreciated. The amyloid expression and assembly is regulated spatio-temporarily within the bacterial cells to perform a diverse function. This review provides a comprehensive account of the genetic regulation associated with the expression of amyloids in bacteria. The stringent control ensures optimal utilization of amyloid scaffold during biofilm biogenesis. We conclude the review by summarizing environmental factors influencing the expression and regulation of amyloids.

RevDate: 2021-10-02
CmpDate: 2021-09-09

Yan H, J Liebig (2021)

Genetic basis of chemical communication in eusocial insects.

Genes & development, 35(7-8):470-482.

Social behavior is one of the most fascinating and complex behaviors in humans and animals. A fundamental process of social behavior is communication among individuals. It relies on the capability of the nervous system to sense, process, and interpret various signals (e.g., pheromones) and respond with appropriate decisions and actions. Eusocial insects, including ants, some bees, some wasps, and termites, display intriguing cooperative social behavior. Recent advances in genetic and genomic studies have revealed key genes that are involved in pheromone synthesis, chemosensory perception, and physiological and behavioral responses to varied pheromones. In this review, we highlight the genes and pathways that regulate queen pheromone-mediated social communication, discuss the evolutionary changes in genetic systems, and outline prospects of functional studies in sociobiology.

RevDate: 2021-04-29
CmpDate: 2021-04-29

Ennis CC, Haeffner NN, Keyser CD, et al (2021)

Comparative mitochondrial genomics of sponge-dwelling snapping shrimps in the genus Synalpheus: Exploring differences between eusocial and non-eusocial species and insights into phylogenetic relationships in caridean shrimps.

Gene, 786:145624.

The genus Synalpheus is a cosmopolitan clade of marine shrimps found in most tropical regions. Species in this genus exhibit a range of social organizations, including pair-forming, communal breeding, and eusociality, the latter only known to have evolved within this genus in the marine realm. This study examines the complete mitochondrial genomes of seven species of Synalpheus and explores differences between eusocial and non-eusocial species considering that eusociality has been shown before to affect the strength of purifying selection in mitochondrial protein coding genes. The AT-rich mitochondrial genomes of Synalpheus range from 15,421 bp to 15,782 bp in length and comprise, invariably, 13 protein-coding genes (PCGs), two ribosomal RNA genes, and 22 transfer RNA genes. A 648 bp to 994 bp long intergenic space is assumed to be the D-loop. Mitochondrial gene synteny is identical among the studied shrimps. No major differences occur between eusocial and non-eusocial species in nucleotide composition and codon usage profiles of PCGs and in the secondary structure of tRNA genes. Maximum likelihood phylogenetic analysis of the complete concatenated PCG complement of 90 species supports the monophyly of the genus Synalpheus and its family Alpheidae. Moreover, the monophyletic status of the caridean families Alvinocaridae, Atyidae, Thoridae, Lysmatidae, Palaemonidae, and Pandalidae within caridean shrimps are fully or highly supported by the analysis. We therefore conclude that mitochondrial genomes contain sufficient phylogenetic information to resolve relationships at high taxonomic levels within the Caridea. Our analysis of mitochondrial genomes in the genus Synalpheus contributes to the understanding of the coevolution between genomic architecture and sociality in caridean shrimps and other marine organisms.

RevDate: 2021-10-18
CmpDate: 2021-10-18

Hurd PJ, Grübel K, Wojciechowski M, et al (2021)

Novel structure in the nuclei of honey bee brain neurons revealed by immunostaining.

Scientific reports, 11(1):6852.

In the course of a screen designed to produce antibodies (ABs) with affinity to proteins in the honey bee brain we found an interesting AB that detects a highly specific epitope predominantly in the nuclei of Kenyon cells (KCs). The observed staining pattern is unique, and its unfamiliarity indicates a novel previously unseen nuclear structure that does not colocalize with the cytoskeletal protein f-actin. A single rod-like assembly, 3.7-4.1 µm long, is present in each nucleus of KCs in adult brains of worker bees and drones with the strongest immuno-labelling found in foraging bees. In brains of young queens, the labelling is more sporadic, and the rod-like structure appears to be shorter (~ 2.1 µm). No immunostaining is detectable in worker larvae. In pupal stage 5 during a peak of brain development only some occasional staining was identified. Although the cellular function of this unexpected structure has not been determined, the unusual distinctiveness of the revealed pattern suggests an unknown and potentially important protein assembly. One possibility is that this nuclear assembly is part of the KCs plasticity underlying the brain maturation in adult honey bees. Because no labelling with this AB is detectable in brains of the fly Drosophila melanogaster and the ant Camponotus floridanus, we tentatively named this antibody AmBNSab (Apis mellifera Brain Neurons Specific antibody). Here we report our results to make them accessible to a broader community and invite further research to unravel the biological role of this curious nuclear structure in the honey bee central brain.

RevDate: 2021-11-12
CmpDate: 2021-11-12

Habenstein J, Schmitt F, Liessem S, et al (2021)

Transcriptomic, peptidomic, and mass spectrometry imaging analysis of the brain in the ant Cataglyphis nodus.

Journal of neurochemistry, 158(2):391-412.

Behavioral flexibility is an important cornerstone for the ecological success of animals. Social Cataglyphis nodus ants with their age-related polyethism characterized by age-related behavioral phenotypes represent a prime example for behavioral flexibility. We propose neuropeptides as powerful candidates for the flexible modulation of age-related behavioral transitions in individual ants. As the neuropeptidome of C. nodus was unknown, we collected a comprehensive peptidomic data set obtained by transcriptome analysis of the ants' central nervous system combined with brain extract analysis by Q-Exactive Orbitrap mass spectrometry (MS) and direct tissue profiling of different regions of the brain by matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) MS. In total, we identified 71 peptides with likely bioactive function, encoded on 49 neuropeptide-, neuropeptide-like, and protein hormone prepropeptide genes, including a novel neuropeptide-like gene (fliktin). We next characterized the spatial distribution of a subset of peptides encoded on 16 precursor proteins with high resolution by MALDI MS imaging (MALDI MSI) on 14 µm brain sections. The accuracy of our MSI data were confirmed by matching the immunostaining patterns for tachykinins with MSI ion images from consecutive brain sections. Our data provide a solid framework for future research into spatially resolved qualitative and quantitative peptidomic changes associated with stage-specific behavioral transitions and the functional role of neuropeptides in Cataglyphis ants.

RevDate: 2021-08-16
CmpDate: 2021-08-13

Andersen SB, J Schluter (2021)

A metagenomics approach to investigate microbiome sociobiology.

Proceedings of the National Academy of Sciences of the United States of America, 118(10):.

RevDate: 2021-07-09
CmpDate: 2021-07-09

Kihlström K, Aiello B, Warrant E, et al (2021)

Wing damage affects flight kinematics but not flower tracking performance in hummingbird hawkmoths.

The Journal of experimental biology, 224(Pt 4): pii:jeb.236240.

Wing integrity is crucial to the many insect species that spend distinct portions of their life in flight. How insects cope with the consequences of wing damage is therefore a central question when studying how robust flight performance is possible with such fragile chitinous wings. It has been shown in a variety of insect species that the loss in lift-force production resulting from wing damage is generally compensated by an increase in wing beat frequency rather than amplitude. The consequences of wing damage for flight performance, however, are less well understood, and vary considerably between species and behavioural tasks. One hypothesis reconciling the varying results is that wing damage might affect fast flight manoeuvres with high acceleration, but not slower ones. To test this hypothesis, we investigated the effect of wing damage on the manoeuvrability of hummingbird hawkmoths (Macroglossum stellatarum) tracking a motorised flower. This assay allowed us to sample a range of movements at different temporal frequencies, and thus assess whether wing damage affected faster or slower flight manoeuvres. We show that hummingbird hawkmoths compensate for the loss in lift force mainly by increasing wing beat amplitude, yet with a significant contribution of wing beat frequency. We did not observe any effects of wing damage on flight manoeuvrability at either high or low temporal frequencies.

RevDate: 2021-02-11
CmpDate: 2021-02-11

Boff S, Scheiner R, Raizer J, et al (2021)

Survival rate and changes in foraging performances of solitary bees exposed to a novel insecticide.

Ecotoxicology and environmental safety, 211:111869.

Solitary bees are among the most important pollinators worldwide however population declines especially in croplands has been noticed. The novel pesticide sulfoxaflor is a competitive modulator of nicotinic acetylcholine receptors (nAChR) in insects. While there is evidence of a negative impact of neonicotinoids on bees of several social organization levels, our overall knowledge on the impact of sulfoxaflor on bees is poor. Here we present for the first time a study showing effects of field realistic doses of sulfoxaflor on solitary bees. Bees submitted to long term exposure of field realistic doses of sulfoxaflor (5 µg dm-3, 10 µg dm-3, 50 µg dm-3) and control were observed regarding their survival rate. Moreover, we recorded metrics related to flower visitation and flight performance. We discover that the highest field realistic dose is lethal to Osmia bicornis along five days of exposure. The effect of sulfoxaflor reduces the outcome of foraging, important features for fruit and seed production of cross-pollinated plant species. Bees exposed to pesticide visited flowers mostly walking rather than flying. Flight performance was also impaired by the pesticide.

RevDate: 2021-01-14

Junker J, Petrovan SO, Arroyo-Rodríguez V, et al (2021)

Corrigendum: A Severe Lack of Evidence Limits Effective Conservation of the World's Primates.

Bioscience, 71(1):105 pii:biaa143.

[This corrects the article DOI: 10.1093/biosci/biaa082.].

RevDate: 2020-12-22

Halawani O, Dunn RR, Grunden AM, et al (2020)

Bacterial exposure leads to variable mortality but not a measurable increase in surface antimicrobials across ant species.

PeerJ, 8:e10412.

Social insects have co-existed with microbial species for millions of years and have evolved a diversity of collective defenses, including the use of antimicrobials. While many studies have revealed strategies that ants use against microbial entomopathogens, and several have shown ant-produced compounds inhibit environmental bacterial growth, few studies have tested whether exposure to environmental bacteria represents a health threat to ants. We compare four ant species' responses to exposure to Escherichia coli and Staphylococcus epidermidis bacteria in order to broaden our understanding of microbial health-threats to ants and their ability to defend against them. In a first experiment, we measure worker mortality of Solenopsis invicta, Brachymyrmex chinensis, Aphaenogaster rudis, and Dorymyrmex bureni in response to exposure to E. coli and S. epidermidis. We found that exposure to E. coli was lethal for S. invicta and D. bureni, while all other effects of exposure were not different from experimental controls. In a second experiment, we compared the antimicrobial ability of surface extracts from bacteria-exposed and non-exposed S. invicta and B. chinensis worker ants, to see if exposure to E. coli or S. epidermidis led to an increase in antimicrobial compounds. We found no difference in the inhibitory effects from either treatment group in either species. Our results demonstrate the susceptibility to bacteria is varied across ant species. This variation may correlate with an ant species' use of surface antimicrobials, as we found significant mortality effects in species which also were producing antimicrobials. Further exploration of a wide range of both bacteria and ant species is likely to reveal unique and nuanced antimicrobial strategies and deepen our understanding of how ant societies respond to microbial health threats.

RevDate: 2021-08-03
CmpDate: 2021-08-03

Maes S, De Reu K, Van Weyenberg S, et al (2020)

Pseudomonas putida as a potential biocontrol agent against Salmonella Java biofilm formation in the drinking water system of broiler houses.

BMC microbiology, 20(1):373.

BACKGROUND: Environmental biofilms can induce attachment and protection of other microorganisms including pathogens, but can also prevent them from invasion and colonization. This opens the possibility for so-called biocontrol strategies, wherein microorganisms are applied to control the presence of other microbes. The potential for both positive and negative interactions between microbes, however, raises the need for in depth characterization of the sociobiology of candidate biocontrol agents (BCAs). The inside of the drinking water system (DWS) of broiler houses is an interesting niche to apply BCAs, because contamination of these systems with pathogens plays an important role in the infection of broiler chickens and consequently humans. In this study, Pseudomonas putida, which is part of the natural microbiota in the DWS of broiler houses, was evaluated as BCA against the broiler pathogen Salmonella Java.

RESULTS: To study the interaction between these species, an in vitro model was developed simulating biofilm formation in the drinking water system of broilers. Dual-species biofilms of P. putida strains P1, P2, and P3 with S. Java were characterized by competitive interactions, independent of P. putida strain, S. Java inoculum density and application order. When equal inocula of S. Java and P. putida strains P1 or P3 were simultaneously applied, the interaction was characterized by mutual inhibition, whereas P. putida strain P2 showed an exploitation of S. Java. Lowering the inoculum density of S. Java changed the interaction with P. putida strain P3 also into an exploitation of S. Java. A further increase in S. Java inhibition was established by P. putida strain P3 forming a mature biofilm before applying S. Java.

CONCLUSIONS: This study provides the first results showing the potential of P. putida as BCA against S. Java in the broiler environment. Future work should include more complex microbial communities residing in the DWS, additional Salmonella strains as well as chemicals typically used to clean and disinfect the system.

RevDate: 2021-09-16
CmpDate: 2021-09-16

Anton S, W Rössler (2021)

Plasticity and modulation of olfactory circuits in insects.

Cell and tissue research, 383(1):149-164.

Olfactory circuits change structurally and physiologically during development and adult life. This allows insects to respond to olfactory cues in an appropriate and adaptive way according to their physiological and behavioral state, and to adapt to their specific abiotic and biotic natural environment. We highlight here findings on olfactory plasticity and modulation in various model and non-model insects with an emphasis on moths and social Hymenoptera. Different categories of plasticity occur in the olfactory systems of insects. One type relates to the reproductive or feeding state, as well as to adult age. Another type of plasticity is context-dependent and includes influences of the immediate sensory and abiotic environment, but also environmental conditions during postembryonic development, periods of adult behavioral maturation, and short- and long-term sensory experience. Finally, plasticity in olfactory circuits is linked to associative learning and memory formation. The vast majority of the available literature summarized here deals with plasticity in primary and secondary olfactory brain centers, but also peripheral modulation is treated. The described molecular, physiological, and structural neuronal changes occur under the influence of neuromodulators such as biogenic amines, neuropeptides, and hormones, but the mechanisms through which they act are only beginning to be analyzed.

RevDate: 2021-01-14
CmpDate: 2021-01-14

Eckhardt F, Pauliny A, Rollings N, et al (2020)

Stress-related changes in leukocyte profiles and telomere shortening in the shortest-lived tetrapod, Furcifer labordi.

BMC evolutionary biology, 20(1):160.

BACKGROUND: Life history theory predicts that during the lifespan of an organism, resources are allocated to either growth, somatic maintenance or reproduction. Resource allocation trade-offs determine the evolution and ecology of different life history strategies and define an organisms' position along a fast-slow continuum in interspecific comparisons. Labord's chameleon (Furcifer labordi) from the seasonal dry forests of Madagascar is the tetrapod species with the shortest reported lifespan (4-9 months). Previous investigations revealed that their lifespan is to some degree dependent on environmental factors, such as the amount of rainfall and the length of the vegetation period. However, the intrinsic mechanisms shaping such a fast life history remain unknown. Environmental stressors are known to increase the secretion of glucocorticoids in other vertebrates, which, in turn, can shorten telomeres via oxidative stress. To investigate to what extent age-related changes in these molecular and cellular mechanisms contribute to the relatively short lifetime of F. labordi, we assessed the effects of stressors indirectly via leukocyte profiles (H/L ratio) and quantified relative telomere length from blood samples in a wild population in Kirindy Forest. We compared our findings with the sympatric, but longer-lived sister species F. cf. nicosiai, which exhibit the same annual timing of reproductive events, and with wild-caught F. labordi that were singly housed under ambient conditions.

RESULTS: We found that H/L ratios were consistently higher in wild F. labordi compared to F. cf. nicosiai. Moreover, F. labordi already exhibited relatively short telomeres during the mating season when they were 3-4 months old, and telomeres further shortened during their post-reproductive lives. At the beginning of their active season, telomere length was relatively longer in F. cf. nicosiai, but undergoing rapid shortening towards the southern winter, when both species gradually die off. Captive F. labordi showed comparatively longer lifespans and lower H/L ratios than their wild counterparts.

CONCLUSION: We suggest that environmental stress and the corresponding accelerated telomere attrition have profound effects on the lifespan of F. labordi in the wild, and identify physiological mechanisms potentially driving their relatively early senescence and mortality.

RevDate: 2022-01-10
CmpDate: 2022-01-10

Grob R, Tritscher C, Grübel K, et al (2021)

Johnston's organ and its central projections in Cataglyphis desert ants.

The Journal of comparative neurology, 529(8):2138-2155.

The Johnston's organ (JO) in the insect antenna is a multisensory organ involved in several navigational tasks including wind-compass orientation, flight control, graviception, and, possibly, magnetoreception. Here we investigate the three dimensional anatomy of the JO and its neuronal projections into the brain of the desert ant Cataglyphis, a marvelous long-distance navigator. The JO of C. nodus workers consists of 40 scolopidia comprising three sensory neurons each. The numbers of scolopidia slightly vary between different sexes (female/male) and castes (worker/queen). Individual scolopidia attach to the intersegmental membrane between pedicel and flagellum of the antenna and line up in a ring-like organization. Three JO nerves project along the two antennal nerve branches into the brain. Anterograde double staining of the antennal afferents revealed that JO receptor neurons project to several distinct neuropils in the central brain. The T5 tract projects into the antennal mechanosensory and motor center (AMMC), while the T6 tract bypasses the AMMC via the saddle and forms collaterals terminating in the posterior slope (PS) (T6I), the ventral complex (T6II), and the ventrolateral protocerebrum (T6III). Double labeling of JO and ocellar afferents revealed that input from the JO and visual information from the ocelli converge in tight apposition in the PS. The general JO anatomy and its central projection patterns resemble situations in honeybees and Drosophila. The multisensory nature of the JO together with its projections to multisensory neuropils in the ant brain likely serves synchronization and calibration of different sensory modalities during the ontogeny of navigation in Cataglyphis.

RevDate: 2021-03-29
CmpDate: 2021-03-29

Dolotovskaya S, Roos C, EW Heymann (2020)

Genetic monogamy and mate choice in a pair-living primate.

Scientific reports, 10(1):20328.

In pair-living mammals, genetic monogamy is extremely rare. One possible reason is that in socially monogamous animals, mate choice can be severely constrained, increasing the risk of inbreeding or pairing with an incompatible or low-quality partner. To escape these constraints, individuals might engage in extra-pair copulations. Alternatively, inbreeding can be avoided by dispersal. However, little is known about the interactions between mating system, mate choice, and dispersal in pair-living mammals. Here we genotyped 41 wild individuals from 14 groups of coppery titi monkeys (Plecturocebus cupreus) in Peruvian Amazon using 18 microsatellite loci. Parentage analyses of 18 young revealed no cases of extra-pair paternity, indicating that the study population is mostly genetically monogamous. We did not find evidence for relatedness- or heterozygosity-based mate choice. Despite the lack of evidence for active inbreeding avoidance via mate choice, mating partners were on average not related. We further found that dispersal was not sex-biased, with both sexes dispersing opportunistically over varying distances. Our findings suggest that even opportunistic dispersal, as long as it is not constrained, can generate sufficient genetic diversity to prevent inbreeding. This, in turn, can render active inbreeding avoidance via mate choice and extra-pair copulations less necessary, helping to maintain genetic monogamy.

RevDate: 2020-11-19

Römer D, Cosarinsky MI, F Roces (2020)

Selection and spatial arrangement of building materials during the construction of nest turrets by grass-cutting ants.

Royal Society open science, 7(10):201312.

Ants build complex nest structures by reacting to simple, local stimuli. While underground nests result from the space generated by digging, some leaf- and grass-cutting ants also construct conspicuous aboveground turrets around nest openings. We investigated whether the selection of specific building materials occurs during turret construction in Acromyrmex fracticornis grass-cutting ants, and asked whether single building decisions at the beginning can modify the final turret architecture. To quantify workers' material selection, the original nest turret was removed and a choice between two artificial building materials, thin and thick sticks, was offered for rebuilding. Workers preferred thick sticks at the very beginning of turret construction, showed varying preferences thereafter, and changed to prefer thin sticks for the upper, final part of the turret, indicating that they selected different building materials over time to create a stable structure. The impact of a single building choice on turret architecture was evaluated by placing artificial beams that divided a colony's nest entrance at the beginning of turret rebuilding. Splitting the nest entrance led to the self-organized construction of turrets with branched galleries ending in multiple openings, showing that the spatial location of a single building material can strongly influence turret morphology.

RevDate: 2021-05-14
CmpDate: 2021-05-14

Kappeler PM (2020)

Evidence for a male sex pheromone in a primate?.

Current biology : CB, 30(22):R1358-R1359.

Pheromones mediate a wide range of functions across the animal kingdom [1], and such chemosensory communication is especially widespread among mammals [2]. In a recent paper in Current Biology, Shirasu, Ito et al. [3] describe the results of a series of chemical and behavioral studies that identified three aldehyde odors released from the wrist gland of ring-tailed lemurs (Lemur catta) that could represent the first identified sex pheromones in male primates. Observations of a captive group and controlled presentations of isolated male scent samples showed captive female lemurs sniffing antebrachial scent marks longer on average during the breeding season. Comparison of the chemical profiles of antebrachial secretions between breeding- and non-breeding-season samples revealed three aldehydes putatively responsible for the female response, the concentration of one of these subsequently shown to increase following testosterone injection of one male. Average sniffing duration of two females increased slightly with increasing concentrations of two of the three aldehydes in one experiment, and so did the response of seven other females to swabs with mixtures of the three compounds, compared to individually presented aldehydes. From these results, the authors conclude that "it is conceivable that the identified C12 and C14 aldehydes are putative sex pheromones that aid male-female interactions among lemurs." Here, I argue that, in fact, more data are needed to determine whether antebrachial marking and these substances are actually involved in mediating the attractiveness of males to females during the breeding season. My specific concerns pertain to several aspects of the methods that produce ambiguous results and conclusions that are too strong, especially when considering the broader context of lemur biology.

RevDate: 2021-01-10
CmpDate: 2021-01-06

Kenyon C (2020)

Emergence of zoonoses such as COVID-19 reveals the need for health sciences to embrace an explicit eco-social conceptual framework of health and disease.

Epidemics, 33:100410.

An accurate understanding of why zoonoses such as SARS-CoV-2 are emerging at an increased rate, is vital to prevent future pandemics from the approximately 700,000 viruses with zoonotic potential. Certain authors have argued that the consumption of wildlife, or human contact with bats was responsible for the emergence of SARS-CoV-2. Others argue that a range of anthropogenic environmental degradations have played a vital role in the emergence of SARS-CoV-2 and other zoonoses. In this opinion piece, I argue that these divergent viewpoints stem, in part, from different foundational conceptual frameworks - biomedical individualist and eco-social frameworks, respectively. Based on the fact that the eco-social framework provides a more complete account of the different types of causal factors underpinning the emergence of zoonoses, I propose that the COVID-19 pandemic provides an additional reason for the health sciences to ground its theory of health and disease in an eco-social conceptual framework.

RevDate: 2020-11-28

Cavaletto G, Faccoli M, Marini L, et al (2020)

Effect of Trap Color on Captures of Bark-and Wood-Boring Beetles (Coleoptera; Buprestidae and Scolytinae) and Associated Predators.

Insects, 11(11):.

Traps baited with attractive lures are increasingly used at entry-points and surrounding natural areas to intercept exotic wood-boring beetles accidentally introduced via international trade. Several trapping variables can affect the efficacy of this activity, including trap color. In this study, we tested whether species richness and abundance of jewel beetles (Buprestidae), bark and ambrosia beetles (Scolytinae), and their common predators (i.e., checkered beetles, Cleridae) can be modified using trap colors different to those currently used for surveillance of jewel beetles and bark and ambrosia beetles (i.e., green or black). We show that green and black traps are generally efficient, but also that many flower-visiting or dark-metallic colored jewel beetles and certain bark beetles are more attracted by other colors. In addition, we show that checkered beetles have color preferences similar to those of their Scolytinae preys, which limits using trap color to minimize their inadvertent removal. Overall, this study confirmed that understanding the color perception mechanisms in wood-boring beetles can lead to important improvements in trapping techniques and thereby increase the efficacy of surveillance programs.

RevDate: 2022-04-17
CmpDate: 2021-10-25

Holze H, Schrader L, J Buellesbach (2021)

Advances in deciphering the genetic basis of insect cuticular hydrocarbon biosynthesis and variation.

Heredity, 126(2):219-234.

Cuticular hydrocarbons (CHCs) have two fundamental functions in insects. They protect terrestrial insects against desiccation and serve as signaling molecules in a wide variety of chemical communication systems. It has been hypothesized that these pivotal dual traits for adaptation to both desiccation and signaling have contributed to the considerable evolutionary success of insects. CHCs have been extensively studied concerning their variation, behavioral impact, physiological properties, and chemical compositions. However, our understanding of the genetic underpinnings of CHC biosynthesis has remained limited and mostly biased towards one particular model organism (Drosophila). This rather narrow focus has hampered the establishment of a comprehensive view of CHC genetics across wider phylogenetic boundaries. This review attempts to integrate new insights and recent knowledge gained in the genetics of CHC biosynthesis, which is just beginning to incorporate work on more insect taxa beyond Drosophila. It is intended to provide a stepping stone towards a wider and more general understanding of the genetic mechanisms that gave rise to the astonishing diversity of CHC compounds across different insect taxa. Further research in this field is encouraged to aim at better discriminating conserved versus taxon-specific genetic elements underlying CHC variation. This will be instrumental in greatly expanding our knowledge of the origins and variation of genes governing the biosynthesis of these crucial phenotypic traits that have greatly impacted insect behavior, physiology, and evolution.

RevDate: 2022-10-05
CmpDate: 2021-11-17

Umek W, B Fischer (2020)

We Should Abandon "Race" as a Biological Category in Biomedical Research.

Female pelvic medicine & reconstructive surgery, 26(12):719-720.

RevDate: 2022-01-10
CmpDate: 2022-01-10

Homberg U, Hensgen R, Rieber E, et al (2021)

Orcokinin in the central complex of the locust Schistocerca gregaria: Identification of immunostained neurons and colocalization with other neuroactive substances.

The Journal of comparative neurology, 529(8):1876-1894.

The central complex is a group of highly interconnected neuropils in the insect brain. It is involved in the control of spatial orientation, based on external compass cues and various internal needs. The functional and neurochemical organization of the central complex has been studied in detail in the desert locust Schistocerca gregaria. In addition to classical neurotransmitters, immunocytochemistry has provided evidence for a major contribution of neuropeptides to neural signaling within the central complex. To complement these data, we have identified all orcokinin-immunoreactive neurons in the locust central complex and associated brain areas. About 50 bilateral pairs of neurons innervating all substructures of the central complex exhibit orcokinin immunoreactivity. Among these were about 20 columnar neurons, 33 bilateral pairs of tangential neurons of the central body, and seven pairs of tangential neurons of the protocerebral bridge. In silico transcript analysis suggests the presence of eight different orcokinin-A type peptides in the desert locust. Double label experiments showed that all orcokinin-immunostained tangential neurons of the lateral accessory lobe cluster were also immunoreactive for GABA and the GABA-synthesizing enzyme glutamic acid decarboxylase. Two types of tangential neurons of the upper division of the central body were, furthermore, also labeled with an antiserum against Dip-allatostatin I. No colocalization was found with serotonin immunostaining. The data provide additional insights into the neurochemical organization of the locust central complex and suggest that orcokinin-peptides of the orcokinin-A gene act as neuroactive substances at all stages of signal processing in this brain area.

RevDate: 2020-11-03

Scheiner R, Strauß S, Thamm M, et al (2020)

The Bacterium Pantoea ananatis Modifies Behavioral Responses to Sugar Solutions in Honeybees.

Insects, 11(10):.

1. Honeybees, which are among the most important pollinators globally, do not only collect pollen and nectar during foraging but may also disperse diverse microbes. Some of these can be deleterious to agricultural crops and forest trees, such as the bacterium Pantoea ananatis, an emerging pathogen in some systems. P. ananatis infections can lead to leaf blotches, die-back, bulb rot, and fruit rot. 2. We isolated P. ananatis bacteria from flowers with the aim of determining whether honeybees can sense these bacteria and if the bacteria affect behavioral responses of the bees to sugar solutions. 3. Honeybees decreased their responsiveness to different sugar solutions when these contained high concentrations of P. ananatis but were not deterred by solutions from which bacteria had been removed. This suggests that their reduced responsiveness was due to the taste of bacteria and not to the depletion of sugar in the solution or bacteria metabolites. Intriguingly, the bees appeared not to taste ecologically relevant low concentrations of bacteria. 4. Synthesis and applications. Our data suggest that honeybees may introduce P. ananatis bacteria into nectar in field-realistic densities during foraging trips and may thus affect nectar quality and plant fitness.

RevDate: 2021-10-08
CmpDate: 2021-01-04

de Winter II, Umanets A, Gort G, et al (2020)

Effects of seasonality and previous logging on faecal helminth-microbiota associations in wild lemurs.

Scientific reports, 10(1):16818.

Gastrointestinal helminth-microbiota associations are shaped by various ecological processes. The effect of the ecological context of the host on the bacterial microbiome and gastrointestinal helminth parasites has been tested in a number of ecosystems and experimentally. This study takes the important step to look at these two groups at the same time and to start to examine how these communities interact in a changing host environment. Fresh faecal samples (N = 335) from eight wild Eulemur populations were collected over 2 years across Madagascar. We used 16S ribosomal RNA gene sequencing to characterise the bacterial microbiota composition, and faecal flotation to isolate and morphologically identify nematode eggs. Infections with nematodes of the genera Callistoura and Lemuricola occurred in all lemur populations. Seasonality significantly contributed to the observed variation in microbiota composition, especially in the dry deciduous forest. Microbial richness and Lemuricola spp. infection prevalence were highest in a previously intensely logged site, whereas Callistoura spp. showed no such pattern. In addition, we observed significant correlations between gastrointestinal parasites and bacterial microbiota composition in these lemurs, with 0.4-0.7% of the variation in faecal bacterial microbiota composition being explained by helminth infections. With this study, we show effects of environmental conditions on gastrointestinal nematodes and bacterial interactions in wild lemurs and believe it is essential to consider the potential role of microbiome-parasite associations on the hosts' GI stability, health, and survival.

RevDate: 2020-10-09

Fichtel C, Dinter K, PM Kappeler (2020)

The lemur baseline: how lemurs compare to monkeys and apes in the Primate Cognition Test Battery.

PeerJ, 8:e10025.

Primates have relatively larger brains than other mammals even though brain tissue is energetically costly. Comparative studies of variation in cognitive skills allow testing of evolutionary hypotheses addressing socioecological factors driving the evolution of primate brain size. However, data on cognitive abilities for meaningful interspecific comparisons are only available for haplorhine primates (great apes, Old- and New World monkeys) although strepsirrhine primates (lemurs and lorises) serve as the best living models of ancestral primate cognitive skills, linking primates to other mammals. To begin filling this gap, we tested members of three lemur species (Microcebus murinus, Varecia variegata, Lemur catta) with the Primate Cognition Test Battery, a comprehensive set of experiments addressing physical and social cognitive skills that has previously been used in studies of haplorhines. We found no significant differences in cognitive performance among lemur species and, surprisingly, their average performance was not different from that of haplorhines in many aspects. Specifically, lemurs' overall performance was inferior in the physical domain but matched that of haplorhines in the social domain. These results question a clear-cut link between brain size and cognitive skills, suggesting a more domain-specific distribution of cognitive abilities in primates, and indicate more continuity in cognitive abilities across primate lineages than previously thought.

RevDate: 2021-07-27
CmpDate: 2021-07-27

Muirhead CS, J Srinivasan (2020)

Small molecule signals mediate social behaviors in C. elegans.

Journal of neurogenetics, 34(3-4):395-403.

The last few decades have seen the structural and functional elucidation of small-molecule chemical signals called ascarosides in C. elegans. Ascarosides mediate several biological processes in worms, ranging from development, to behavior. These signals are modular in their design architecture, with their building blocks derived from metabolic pathways. Behavioral responses are not only concentration dependent, but also are influenced by the current physiological state of the animal. Cellular and circuit-level analyses suggest that these signals constitute a complex communication system, employing both synergistic molecular elements and sex-specific neuronal circuits governing the response. In this review, we discuss research from multiple laboratories, including our own, that detail how these chemical signals govern several different social behaviors in C. elegans. We propose that the ascaroside repertoire represents a link between diverse metabolic and neurobiological life-history traits and governs the survival of C. elegans in its natural environment.

RevDate: 2021-03-28
CmpDate: 2020-12-23

Zittrell F, Pfeiffer K, U Homberg (2020)

Matched-filter coding of sky polarization results in an internal sun compass in the brain of the desert locust.

Proceedings of the National Academy of Sciences of the United States of America, 117(41):25810-25817.

Many animals use celestial cues for spatial orientation. These include the sun and, in insects, the polarization pattern of the sky, which depends on the position of the sun. The central complex in the insect brain plays a key role in spatial orientation. In desert locusts, the angle of polarized light in the zenith above the animal and the direction of a simulated sun are represented in a compass-like fashion in the central complex, but how both compasses fit together for a unified representation of external space remained unclear. To address this question, we analyzed the sensitivity of intracellularly recorded central-complex neurons to the angle of polarized light presented from up to 33 positions in the animal's dorsal visual field and injected Neurobiotin tracer for cell identification. Neurons were polarization sensitive in large parts of the virtual sky that in some cells extended to the horizon in all directions. Neurons, moreover, were tuned to spatial patterns of polarization angles that matched the sky polarization pattern of particular sun positions. The horizontal components of these calculated solar positions were topographically encoded in the protocerebral bridge of the central complex covering 360° of space. This whole-sky polarization compass does not support the earlier reported polarization compass based on stimulation from a small spot above the animal but coincides well with the previously demonstrated direct sun compass based on unpolarized light stimulation. Therefore, direct sunlight and whole-sky polarization complement each other for robust head direction coding in the locust central complex.

RevDate: 2020-10-01

Schubiger MN, Fichtel C, JM Burkart (2020)

Validity of Cognitive Tests for Non-human Animals: Pitfalls and Prospects.

Frontiers in psychology, 11:1835.

Comparative psychology assesses cognitive abilities and capacities of non-human animals and humans. Based on performance differences and similarities in various species in cognitive tests, it is inferred how their minds work and reconstructed how cognition might have evolved. Critically, such species comparisons are only valid and meaningful if the tasks truly capture individual and inter-specific variation in cognitive abilities rather than contextual variables that might affect task performance. Unlike in human test psychology, however, cognitive tasks for non-human primates (and most other animals) have been rarely evaluated regarding their measurement validity. We review recent studies that address how non-cognitive factors affect performance in a set of commonly used cognitive tasks, and if cognitive tests truly measure individual variation in cognitive abilities. We find that individual differences in emotional and motivational factors primarily affect performance via attention. Hence, it is crucial to systematically control for attention during cognitive tasks to obtain valid and reliable results. Aspects of test design, however, can also have a substantial effect on cognitive performance. We conclude that non-cognitive factors are a minor source of measurement error if acknowledged and properly controlled for. It is essential, however, to validate and eventually re-design several primate cognition tasks in order to ascertain that they capture the cognitive abilities they were designed to measure. This will provide a more solid base for future cognitive comparisons within primates but also across a wider range of non-human animal species.

RevDate: 2020-12-17
CmpDate: 2020-12-01

Fleischmann PN, Grob R, W Rössler (2020)

Magnetoreception in Hymenoptera: importance for navigation.

Animal cognition, 23(6):1051-1061.

The use of information provided by the geomagnetic field (GMF) for navigation is widespread across the animal kingdom. At the same time, the magnetic sense is one of the least understood senses. Here, we review evidence for magnetoreception in Hymenoptera. We focus on experiments aiming to shed light on the role of the GMF for navigation. Both honeybees and desert ants are well-studied experimental models for navigation, and both use the GMF for specific navigational tasks under certain conditions. Cataglyphis desert ants use the GMF as a compass cue for path integration during their initial learning walks to align their gaze directions towards the nest entrance. This represents the first example for the use of the GMF in an insect species for a genuine navigational task under natural conditions and with all other navigational cues available. We argue that the recently described magnetic compass in Cataglyphis opens up a new integrative approach to understand the mechanisms underlying magnetoreception in Hymenoptera on different biological levels.

RevDate: 2021-02-23

Junker J, Petrovan SO, Arroyo-RodrÍguez V, et al (2020)

A Severe Lack of Evidence Limits Effective Conservation of the World's Primates.

Bioscience, 70(9):794-803.

Threats to biodiversity are well documented. However, to effectively conserve species and their habitats, we need to know which conservation interventions do (or do not) work. Evidence-based conservation evaluates interventions within a scientific framework. The Conservation Evidence project has summarized thousands of studies testing conservation interventions and compiled these as synopses for various habitats and taxa. In the present article, we analyzed the interventions assessed in the primate synopsis and compared these with other taxa. We found that despite intensive efforts to study primates and the extensive threats they face, less than 1% of primate studies evaluated conservation effectiveness. The studies often lacked quantitative data, failed to undertake postimplementation monitoring of populations or individuals, or implemented several interventions at once. Furthermore, the studies were biased toward specific taxa, geographic regions, and interventions. We describe barriers for testing primate conservation interventions and propose actions to improve the conservation evidence base to protect this endangered and globally important taxon.

RevDate: 2021-05-20
CmpDate: 2021-05-20

Değirmenci L, Geiger D, Rogé Ferreira FL, et al (2020)

CRISPR/Cas 9-Mediated Mutations as a New Tool for Studying Taste in Honeybees.

Chemical senses, 45(8):655-666.

Honeybees rely on nectar as their main source of carbohydrates. Sucrose, glucose, and fructose are the main components of plant nectars. Intriguingly, honeybees express only 3 putative sugar receptors (AmGr1, AmGr2, and AmGr3), which is in stark contrast to many other insects and vertebrates. The sugar receptors are only partially characterized. AmGr1 detects different sugars including sucrose and glucose. AmGr2 is assumed to act as a co-receptor only, while AmGr3 is assumedly a fructose receptor. We show that honeybee gustatory receptor AmGr3 is highly specialized for fructose perception when expressed in Xenopus oocytes. When we introduced nonsense mutations to the respective AmGr3 gene using CRISPR/Cas9 in eggs of female workers, the resulting mutants displayed almost a complete loss of responsiveness to fructose. In contrast, responses to sucrose were normal. Nonsense mutations introduced by CRISPR/Cas9 in honeybees can thus induce a measurable behavioral change and serve to characterize the function of taste receptors in vivo. CRISPR/Cas9 is an excellent novel tool for characterizing honeybee taste receptors in vivo. Biophysical receptor characterization in Xenopus oocytes and nonsense mutation of AmGr3 in honeybees unequivocally demonstrate that this receptor is highly specific for fructose.

RevDate: 2021-02-26
CmpDate: 2021-02-26

Helfrecht C, Roulette JW, Lane A, et al (2020)

Life history and socioecology of infancy.

American journal of physical anthropology, 173(4):619-629.

OBJECTIVES: Evolution of human maternal investment strategies is hypothesized to be tied to biological constraints and environmental cues. It is likely, however, that the socioecological context in which mothers' decisions are made is equally important. Yet, a lack of studies examining maternal investment from a cross-cultural, holistic approach has hindered our ability to investigate the evolution of maternal investment strategies. Here, we take a systems-level approach to study how human life history characteristics, environments, and socioecology influence maternal investment in their children.

MATERIALS AND METHODS: We test how infant age and sex, maternal age, parity, and child loss, and the composition of a child's cooperative breeding network are associated with maternal investment across three small-scale (hunter-gatherer, horticultural, and agropastoral), sub-Saharan populations (N = 212). Naturalistic behavioral observations also enable us to illustrate the breadth and depth of the human cooperative breeding system.

RESULTS: Results indicate that infant age, maternal age and parity, and an infant's cooperative childcare network are significantly associated with maternal investment, controlling for population. We also find that human allomaternal care is conducted by a range of caregivers, occupying different relational, sex, and age categories. Moreover, investment by allomothers is widely distributed.

DISCUSSION: Our findings illustrate the social context in which children are reared in contemporary small-scale populations, and in which they were likely reared throughout our evolutionary history. The diversity of the caregiving network, coupled with life history characteristics, is predictive of maternal investment strategies, demonstrating the importance of cooperation in the evolution of human ontogeny.

RevDate: 2021-01-30
CmpDate: 2021-01-26

Rasolofoniaina BN, Kappeler PM, C Fichtel (2021)

Neophobia and social facilitation in narrow-striped mongooses.

Animal cognition, 24(1):165-175.

Social learning is widespread in the animal kingdom, but individuals can differ in how they acquire and use social information. Personality traits, such as neophobia, may, for example, promote individual learning strategies. Here, we contribute comparative data on social learning strategies in carnivorans by examining whether narrow-striped mongooses (Mungotictis decemlineata), a group-living Malagasy euplerid, learn socially and whether neophobia influences social learning. To this end, we tested seven wild female groups with a two-option artificial feeding box, using a demonstrator-observer paradigm, and conducted novel object tests to assess neophobia. In five groups, one individual was trained as a demonstrator displaying one of the techniques, whereas the other two groups served as control groups. Neophobia did not co-vary with an individual's propensity to seek social information. However, less neophobic individuals, and individuals that tended to seek social information, learned the task faster. Moreover, individuals in demonstrator groups learned the task faster than those in groups without a demonstrator and used the demonstrated technique more often. Hence, narrow-striped mongooses rely on social facilitation and local or stimulus enhancement to solve new problems. Finally, our results suggest that several individual characteristics should be taken into consideration to obtain a more comprehensive understanding of social learning strategies.

RevDate: 2021-04-19
CmpDate: 2021-04-19

Cantor M, Maldonado-Chaparro AA, Beck KB, et al (2021)

The importance of individual-to-society feedbacks in animal ecology and evolution.

The Journal of animal ecology, 90(1):27-44.

The social decisions that individuals make-who to interact with and how frequently-give rise to social structure. The resulting social structure then determines how individuals interact with their surroundings-resources and risks, pathogens and predators, competitors and cooperators. However, despite intensive research on (a) how individuals make social decisions and (b) how social structure shapes social processes (e.g. cooperation, competition and conflict), there are still few studies linking these two perspectives. These perspectives represent two halves of a feedback loop: individual behaviour scales up to define the social environment, and this environment, in turn, feeds back by shaping the selective agents that drive individual behaviour. We first review well-established research areas that have captured both elements of this feedback loop-host-pathogen dynamics and cultural transmission. We then highlight areas where social structure is well studied but the two perspectives remain largely disconnected. Finally, we synthesise existing research on 14 distinct research topics to identify new prospects where the interplay between social structure and social processes are likely to be important but remain largely unexplored. Our review shows that the inherent links between individuals' traits, their social decisions, social structure and social evolution, warrant more consideration. By mapping the existing and missing connections among many research areas, our review highlights where explicitly considering social structure and the individual-to-society feedbacks can reveal new dimensions to old questions in ecology and evolution.

RevDate: 2020-10-30

Leonhardt SD, Lihoreau M, J Spaethe (2020)

Mechanisms of Nutritional Resource Exploitation by Insects.

Insects, 11(9):.

Insects have evolved an extraordinary range of nutritional adaptations to exploit other animals, plants, bacteria, fungi and soils as resources in terrestrial and aquatic environments. This special issue provides some new insights into the mechanisms underlying these adaptations. Contributions comprise lab and field studies investigating the chemical, physiological, cognitive and behavioral mechanisms that enable resource exploitation and nutrient intake regulation in insects. The collection of papers highlights the need for more studies on the comparative sensory ecology, underlying nutritional quality assessment, cue perception and decision making to fully understand how insects adjust resource selection and exploitation in response to environmental heterogeneity and variability.

RevDate: 2021-08-27
CmpDate: 2020-09-23

Ruedenauer FA, Sydow D, Spaethe J, et al (2020)

Young bumblebees may rely on both direct pollen cues and early experience when foraging.

Proceedings. Biological sciences, 287(1933):20201615.

An adequate supply of macro- and micronutrients determines health and reproductive success in most animals. Many bee species, for example, collect nectar and pollen to satisfy their demands for carbohydrates, protein and fat, respectively. Bees can assess the quality of pollen by feeding on it, but also pre-digestively by means of chemotactile assessment. Whether they additionally use larval nutritional experience, as has been shown for Drosophila melanogaster and Bombyx mori, is unknown. In this study, we tested whether pollen selection of bumblebee foragers is affected by nutritional experience (acquired before the onset of foraging) or solely by food quality. Bumblebee larvae were fed with one out of three different pollen blends. As adults, they were offered all three blends when they started foraging for the first time. We found all treatment groups to prefer one out of the three blends. This blend provided the highest nutritional quality and increased the bees' lifespan, as shown by feeding studies with microcolonies. Besides, bees also chose the pollen blend fed during their larval stage more often than expected, indicating a significant effect of pre-foraging experience on adult pollen foraging behaviour. The combination of both direct pollen quality assessment and pre-foraging experience (i.e. during the larval phase or as early imagines) seems to allow foraging bumblebees to efficiently select the most suitable pollen for their colony.

RevDate: 2021-08-27
CmpDate: 2020-09-23

Imrit MA, Dogantzis KA, Harpur BA, et al (2020)

Eusociality influences the strength of negative selection on insect genomes.

Proceedings. Biological sciences, 287(1933):20201512.

While much of the focus of sociobiology concerns identifying genomic changes that influence social behaviour, we know little about the consequences of social behaviour on genome evolution. It has been hypothesized that social evolution can influence the strength of negative selection via two mechanisms. First, division of labour can influence the efficiency of negative selection in a caste-specific manner; indirect negative selection on worker traits is theoretically expected to be weaker than direct selection on queen traits. Second, increasing social complexity is expected to lead to relaxed negative selection because of its influence on effective population size. We tested these two hypotheses by estimating the strength of negative selection in honeybees, bumblebees, paper wasps, fire ants and six other insects that span the range of social complexity. We found no consistent evidence that negative selection was significantly stronger on queen-biased genes relative to worker-biased genes. However, we found strong evidence that increased social complexity reduced the efficiency of negative selection. Our study clearly illustrates how changes in behaviour can influence patterns of genome evolution by modulating the strength of natural selection.

RevDate: 2020-10-30
CmpDate: 2020-10-30

Dent R (2020)

Subject 01: exemplary Indigenous masculinity in Cold War genetics.

British journal for the history of science, 53(3):311-332.

In 1962 a team of scientists conducted their first joint fieldwork in a Xavante village in Central Brazil. Recycling long-standing notions that living Indigenous people represented human prehistory, the scientists saw Indigenous people as useful subjects of study not only due to their closeness to nature, but also due to their sociocultural and political realities. The geneticists' vision crystalized around one subject - the famous chief Apöwẽ. Through Apöwẽ, the geneticists fixated on what they perceived as the political prowess, impressive physique, and masculine reproductive aptitude of Xavante men. These constructions of charismatic masculinity came at the expense of recognizing how profoundly colonial expansion into Mato Grosso had destabilized Xavante communities, stripping them of their land and introducing epidemic disease. The geneticists' theorizing prefigured debates to come in sociobiology, and set up an enduring research programme that Apöwẽ continues to animate even four decades after his death.

RevDate: 2022-05-31
CmpDate: 2021-11-18

Poelstra JW, Salmona J, Tiley GP, et al (2021)

Cryptic Patterns of Speciation in Cryptic Primates: Microendemic Mouse Lemurs and the Multispecies Coalescent.

Systematic biology, 70(2):203-218.

Mouse lemurs (Microcebus) are a radiation of morphologically cryptic primates distributed throughout Madagascar for which the number of recognized species has exploded in the past two decades. This taxonomic revision has prompted understandable concern that there has been substantial oversplitting in the mouse lemur clade. Here, we investigate mouse lemur diversity in a region in northeastern Madagascar with high levels of microendemism and predicted habitat loss. We analyzed RADseq data with multispecies coalescent (MSC) species delimitation methods for two pairs of sister lineages that include three named species and an undescribed lineage previously identified to have divergent mtDNA. Marked differences in effective population sizes, levels of gene flow, patterns of isolation-by-distance, and species delimitation results were found among the two pairs of lineages. Whereas all tests support the recognition of the presently undescribed lineage as a separate species, the species-level distinction of two previously described species, M. mittermeieri and M. lehilahytsara is not supported-a result that is particularly striking when using the genealogical discordance index (gdi). Nonsister lineages occur sympatrically in two of the localities sampled for this study, despite an estimated divergence time of less than 1 Ma. This suggests rapid evolution of reproductive isolation in the focal lineages and in the mouse lemur clade generally. The divergence time estimates reported here are based on the MSC calibrated with pedigree-based mutation rates and are considerably more recent than previously published fossil-calibrated relaxed-clock estimates. We discuss the possible explanations for this discrepancy, noting that there are theoretical justifications for preferring the MSC estimates in this case. [Cryptic species; effective population size; microendemism; multispecies coalescent; speciation; species delimitation.].

RevDate: 2020-09-28

Yordy J, Kraus C, Hayward JJ, et al (2020)

Body size, inbreeding, and lifespan in domestic dogs.

Conservation genetics (Print), 21(1):137-148.

Inbreeding poses a real or potential threat to nearly every species of conservation concern. Inbreeding leads to loss of diversity at the individual level, which can cause inbreeding depression, and at the population level, which can hinder ability to respond to a changing environment. In closed populations such as endangered species and ex situ breeding programs, some degree of inbreeding is inevitable. It is therefore vital to understand how different patterns of breeding and inbreeding can affect fitness in real animals. Domestic dogs provide an excellent model, showing dramatic variation in degree of inbreeding and in lifespan, an important aspect of fitness that is known to be impacted by inbreeding in other species. There is a strong negative correlation between body size and lifespan in dogs, but it is unknown whether the higher rate of aging in large dogs is due to body size per se or some other factor associated with large size. We used dense genome-wide SNP array data to calculate average inbreeding for over 100 dog breeds based on autozygous segment length and found that large breeds tend to have higher coefficients of inbreeding than small breeds. We then used data from the Veterinary medical Database and other published sources to estimate life expectancies for pure and mixed breed dogs. When controlling for size, variation in inbreeding was not associated with life expectancy across breeds. When comparing mixed versus purebred dogs, however, mixed breed dogs lived about 1.2 years longer on average than size-matched purebred dogs. Furthermore, individual pedigree coefficients of inbreeding and lifespans for over 9000 golden retrievers showed that inbreeding does negatively impact lifespan at the individual level. Registration data from the American Kennel Club suggest that the molecular inbreeding patterns observed in purebred dogs result from specific breeding practices and/or founder effects and not the current population size. Our results suggest that recent inbreeding, as reflected in variation within a breed, is more likely to affect fitness than historic inbreeding, as reflected in variation among breeds. Our results also indicate that occasional outcrosses, as in mixed breed dogs, can have a substantial positive effect on fitness.

RevDate: 2021-03-15
CmpDate: 2021-03-15

Sharma A, Singh P, Sarmah BK, et al (2020)

Quorum sensing: its role in microbial social networking.

Research in microbiology, 171(5-6):159-164.

Twentieth century observed a huge paradigm shift in the field of sociobiology, which moved from social intelligence of animals to microbes. Quorum Sensing Molecules (QSMs) are the small chemical molecules, which establish the mode of communication among microbes, and is called Quorum Sensing (QS). These molecules are crucial for determining the decisions of large groups of cells, which is a density-dependent process. Thus, this mechanism draws a very thin line between bacteria that are actually prokaryotes and clustered bacteria mimicking eukaryotes. This review discusses about the designs of microbial communication networks, and the role of QS in plant-microbe interaction.

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ESP Quick Facts

ESP Origins

In the early 1990's, Robert Robbins was a faculty member at Johns Hopkins, where he directed the informatics core of GDB — the human gene-mapping database of the international human genome project. To share papers with colleagues around the world, he set up a small paper-sharing section on his personal web page. This small project evolved into The Electronic Scholarly Publishing Project.

ESP Support

In 1995, Robbins became the VP/IT of the Fred Hutchinson Cancer Research Center in Seattle, WA. Soon after arriving in Seattle, Robbins secured funding, through the ELSI component of the US Human Genome Project, to create the original ESP.ORG web site, with the formal goal of providing free, world-wide access to the literature of classical genetics.

ESP Rationale

Although the methods of molecular biology can seem almost magical to the uninitiated, the original techniques of classical genetics are readily appreciated by one and all: cross individuals that differ in some inherited trait, collect all of the progeny, score their attributes, and propose mechanisms to explain the patterns of inheritance observed.

ESP Goal

In reading the early works of classical genetics, one is drawn, almost inexorably, into ever more complex models, until molecular explanations begin to seem both necessary and natural. At that point, the tools for understanding genome research are at hand. Assisting readers reach this point was the original goal of The Electronic Scholarly Publishing Project.

ESP Usage

Usage of the site grew rapidly and has remained high. Faculty began to use the site for their assigned readings. Other on-line publishers, ranging from The New York Times to Nature referenced ESP materials in their own publications. Nobel laureates (e.g., Joshua Lederberg) regularly used the site and even wrote to suggest changes and improvements.

ESP Content

When the site began, no journals were making their early content available in digital format. As a result, ESP was obliged to digitize classic literature before it could be made available. For many important papers — such as Mendel's original paper or the first genetic map — ESP had to produce entirely new typeset versions of the works, if they were to be available in a high-quality format.

ESP Help

Early support from the DOE component of the Human Genome Project was critically important for getting the ESP project on a firm foundation. Since that funding ended (nearly 20 years ago), the project has been operated as a purely volunteer effort. Anyone wishing to assist in these efforts should send an email to Robbins.

ESP Plans

With the development of methods for adding typeset side notes to PDF files, the ESP project now plans to add annotated versions of some classical papers to its holdings. We also plan to add new reference and pedagogical material. We have already started providing regularly updated, comprehensive bibliographies to the ESP.ORG site.

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This is the book that really started the notion of sociobiology. It came out just as I was starting graduate school and the animal-behavior group organized a discussion group around the book. I was very lucky to have my introduction to in-depth academic discourse be centered around such an interesting book. R. Robbins

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Papers in Classical Genetics

The ESP began as an effort to share a handful of key papers from the early days of classical genetics. Now the collection has grown to include hundreds of papers, in full-text format.

Digital Books

Along with papers on classical genetics, ESP offers a collection of full-text digital books, including many works by Darwin (and even a collection of poetry — Chicago Poems by Carl Sandburg).

Timelines

ESP now offers a much improved and expanded collection of timelines, designed to give the user choice over subject matter and dates.

Biographies

Biographical information about many key scientists.

Selected Bibliographies

Bibliographies on several topics of potential interest to the ESP community are now being automatically maintained and generated on the ESP site.

ESP Picks from Around the Web (updated 07 JUL 2018 )