Louis Agassiz attacks Darwin's the origin of species, rejecting the idea of evolution of the species and arguing that each species was created separately.

Thomas Henry Huxley (sometimes known as Darwin's bulldog) clashes with Bishop "Soapy Sam" Wilberforce about evolution at the annual meeting of The British Association for the Advancement of Science, in what has come to be known as the Huxley-Wilberforce debate.

Bishop Wilberforce is supposed to have asked Huxley sarcastically whether "it was through his grandfather or his grandmother that he claimed descent from a monkey." Huxley responded, "If then the question is put to me whether I would rather have a miserable ape for a grandfather or a man highly endowed by nature and possessed of great means of influence and yet employs these faculties and that influence for the mere purpose of introducing ridicule into a grave scientific discussion, I unhesitatingly affirm my preference for the ape." Or words to that effect.

John Phillips diagrams the progressive but fluctuating diversity of life on Earth based on the fossil record. His work evidences massive extinctions at the end of the Paleozoic and Mesozoic, and increased diversity in each subsequent age.

Louis Pasteur becomes significantly involved in biological research with the publication of "Mémoir sur la fermentation alcoolique" in which he showed that alcoholic fermentation seemed to be carried out by yeast, which were themselves living organisms.

Between 1861 and 1862, Max Johann Sigismund Schultze (Germany) and Heinrich Anton de Bary (Germany) establish the essential unity of protoplasm in all living cells.

First recognized fossil Archaeopteryx lithographica skeleton is found in the stone quarries of Solnhofen.

In "Mémoires sur les corpuscles organisés qui existent dans l'atmosphère," Pasteur applies heat to bent-neck flasks to show unequivocally that the "organized bodies" (microbes) which drive fermentation originate from "organized bodies" that exist in the atmosphere. In this elegant series of experiments, Pasteur laid to rest the long-held belief in spontaneous generation."

In his presidential address to the Geological Society of London, Leonard Horner proposes removing the world's "creation" date of 4004 BC from the English Bible, citing geological evidence of a much older planet.

Lord Kelvin asserts that the Earth and sun are cooling from their initial formation, between 20 and 400 million years ago. He will later adopt the smaller number.

Anti-evolutionist James Hunt, founder of the Anthropological Society of London, gives a presidential address to the society stating that human races were created separately. He further argues that the African species is closer in ability to apes than to Europeans.

Alfred Russel Wallace describes the "Wallace line," the dividing line between Indo-Malayan and Austro-Malayan fauna, in Proceedings of the Royal Geographical Society of London.

Dominique Alexandre Godron and Charles Victor Naudin (France) independently report experiments in plant hybridization. Naudin confirmed Sageret's work, in general discussed work of the early hybridizers, and reported dominance and segregation in Datura (jimsonweed) hybrids. He did not deal with single characters and reported no statistical observations on the second generation. His theoretical explanation of his facts was a forerunner of Mendel's ideas, but inferred rather than deduced.

T. H. Huxley publishes Man's Place in Nature discussing human and primate paleontology, and showing similarities between humans and other animals.

Father-and-son glassworkers Leopold and Rudolf Blaschka begin making glass models of marine invertebrates. Marine biologists will refer to their exquisitely detailed, accurate models 150 years later while trying to see how many of the depicted species can still be found in the wild.

Abraham Lincoln forms the National Academy of Sciences.

Ernst Haeckel (Häckel) outlines the essential elements of modern zoological classification.

James Clerk Maxwell's A dynamical theory of the electromagnetic field is the first of his publications to use Michael Faraday's concept of a field as the basis of the mathematical treatment of electricity and magnetism. It introduces Maxwell's equations to describe electromagnetism.

John Lubbock publishes Prehistoric Times dividing what has previously been understood to be the Stone Age into two parts: the older Paleolithic and the newer Neolithic. In the same book, he also argues that modern Tasmanians and Fuegians are throwbacks to archaic humans.

Franz Schweigger-Seidel and A. von la Valette St. George (Germany) independently prove that a spermatozoon is a single cell and contains nucleus and cytoplasm

Gregor Mendel presents his work on inheritance in peas to the Brünn Natural History Society. The results are published the following year.

Sir John William Dawson of McGill University identifies "shells" of huge foraminiferal protozoans. Known as Eozoön or "dawn animal," this find is used as an argument against evolution because it shows a relatively "modern" animal early in the fossil record. It will prove, however, to be a geologically young pseudofossil formed by heat and pressure on limestone.

Paolo Mantegazza publishes Degli Innesti Animali e della Produzione Artificiale delle Cellule (On Animal Grafts and Artificial Cell Production) describing the results of a series of interspecies animal grafts, such as the transplant of a cockspur onto a cow ear. Grafts described include transplants between dogs, frogs and rodents. Mantegazza reports that some grafts decomposed while others became "pathological tumours."

Rudolf Clausius invents the term ENTROPY to describe the degradation of energy in the closed system.

German zoologist Ernst Haeckel publishes General Morphology of Organisms, the first detailed genealogical tree relating all known organisms, incorporating the principles of Darwinian evolution.

Ernst Heinrich Haeckel (Häckel) hypothesizes that the nucleus of a cell transmits its hereditary information.

Mendel publishes his work on heredity, Versuche über Pflanzen Hybriden.

Ernst Heinrich Haeckel (Häckel) first used the term ECOLOGY to describe the study of living organisms and their interactions with other organisms and with their environment.

Orléans Railway Company employee Peccadeau de l'Isle presents a paper to the French Academy of Sciences on his recent discoveries at Montastruc, including a mammoth carved from a reindeer antler, and two reindeer (found in separate pieces) carved from a mammoth tusk. The finds will eventually be dated at about 13,000 years old.

H. S. Bidwell (United States) reports controlled pollination in maize.

Charles Darwin publishes The Variation of Animals and Plants under Domestication, in which he offers his own theory of heredity, which he called the "Provisional Hypothesis of Pangenesis."

Ernst Haeckel publishes Natürliche Schöpfungsgeschichte, subdividing humanity into 12 separate species. He also asserts that evolution consists of 22 phases, the 21st being the "missing link" between apes and humans.

Thomas Henry Huxley publishes "On the Animals which are Most Nearly Intermediate between Birds and Reptiles," arguing that birds are descendants of dinosaurs. This suggestion will not be taken very seriously for another century.

Three human skulls and other skeletal remains, roughly 30,000 years old, are discovered at a rock shelter called Cro-Magnon (old French for "big hole").

Francis Galton publishes Hereditary Genius. In it he describes a scientific study of human pedigrees from which he concludes that intelligence has a genetic basis.

Huxley, Norman Lockyer and others found Nature Magazine, which becomes one of the world's two most important scientific journals. (The other journal is Science.)