Based on studies of Y chromosomes, Peter Underhill publishes his finding that all modern humans share a common ancestor, bolstering the 1987 announcement from Cann and Wilson. This suggests a "bottleneck" event (population crash) among human ancestors living in Africa roughly 150,000 years ago.

Sally McBearty and Alison Brooks publish "The Revolution that Wasn't" challenging the long-held notion of a "big bang" in human intellectual evolution approximately 40,000 years ago. Instead, they cite evidence for earlier appearances of modern behavior.

A research team led by Paul Sereno discovers Rugops primus ("first wrinkle face") in the Sahara. This dinosaur's resemblance to South American fossils suggests that Africa separated from the ancient landmass of Gondwana more recently than previously thought.

Phil Currie publishes a paper suggesting that T. rex was a social animal that hunted in packs.

Alfred Sturtevant's A History of Genetics is republished jointly by the Electronic Scholarly Publishing Project and the Cold Spring Harbor Laboratory Press. Sturtevant provides an insider's perspective (he created the FIRST GENETIC MAP ) to this first-rate summary of the foundations of classical genetics.

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The International Human Genome Sequencing Consortium (Human Genome Project) publishes the initial sequence and analysis of the human genome in Nature Magazine. Celera Genomics simultaneously publishes a draft human genome sequence in Science Magazine.

Leland H. Hartwell, R. Timothy Hunt, and Sir Paul M. Nurse share a Nobel Prize in Medicine for their discoveries of key regulators of the cell cycle.

Chris Henshilwood and collaborators discover and describe 77,000-year-old artwork: stones carved with lines and triangles, from Blombos Cave on the Southern Cape coast of Africa. Three years later, Henshilwood and collaborators will describe more Blombos artifacts: tiny snail shells that were apparently pierced and worn as jewelry about 76,000 years ago. A few years after that, another research team will describe similar shell beads, at least 100,000 years old, in Israel and Algeria.

Joshua Smith and collaborators publish a description of a giant sauropod from Egypt, possibly the largest Cretaceous sauropod yet discovered. It is considered a possible food source for three large carnivorous dinosaur species discovered decades earlier by Ernst Stromer.

Luann Becker and collaborators publish a paper describing carbon fullerenes (buckyballs) at the Permo-Triassic boundary in China, Japan and Hungary. Because they can occur in meteorites, the fullerenes are cited as evidence of a meteorite impact at the end of the Permian. Other scientists will have difficulty reproducing their results, however, and the researchers' claim will remain controversial.

Odin and Néraudeau publish a description of a Neanderthal flint tool found in southwestern France with a fossil sea urchin on one side.

Sydney Brenner, H. Robert Horvitz, and John E. Sulston share a Nobel Prize in Medicine for their discoveries concerning genetic regulation of organ development and programmed cell death.

David Lordkipanidze and collaborators excavate a 1.77-million-year-old Homo erectus skull of a "toothless old man" in Dmanisi. New bone growth after the loss of his teeth suggests that he was cared for by others, the oldest evidence yet found of care for the sick in fossil hominids.

Michel Brunet and collaborators publish a description of Sahelanthropus tchadensis, a hominid fossil from western central Africa. Suspected to be 6 to 7 million years old, it is possibly the oldest hominid fossil yet found. Its location, in Chad, is expected to spur hominid fossil hunting west of Africa's Rift Valley.

M.R. Sánchez-Villagra, O. Aguilera and I. Horovitz publish a description of Phoberomys, a fossil rodent from Venezuela the size of a buffalo.

Paleontologists in Germany identify the world's oldest pantry: an underground burrow system probably dug by an extinct species of ground squirrel or hamster. Estimated at 17 million years old, the food stash is stuffed with more than 1,800 fossilized nuts.

Paleontologists led by John Horner find a T. rex fossil that will later yield evidence of blood vessels and blood cells. The fossil will also prove to be an egg-laying female.

Two separate teams, digging 2,000 miles apart, find two new Antarctic dinosaurs in the same week. One appears to be a Jurassic sauropod, the other a Cretaceous theropod.

Peter Brown, Mike Morwood and collaborators announce the find of a 1-meter- tall hominid skeleton on the Indonesian island of Flores. Found near the remains of giant lizards and pygmy elephants, the new species is formally named Homo floresiensis and nicknamed the "hobbit." Though some suspect it's a kind of malformed, small-brained midget, this interpretation will be answered by braincase scans, wrist bones too primitive to be Homo sapiens, and the announcement of several more individuals of the same species. Later studies will suggest direct ancestry from Homo erectus, although another study will argue the remains really indicate Down syndrome. The species is initially given an estimated age as young as 11,000 years, but later research will indicate an age of at least 50,000 years.

A 70-million-year-old mammal jaw is found in Pui, Romania, some 100 miles from Vlad Dracula's castle. Eleven years later, the animal will be formally named Barbatodon transylvanicus by scientists who note that strengthening iron, not blood drinking, gives the teeth their bright red color.

D. Néraudeau describes deposits in western France revealing hundreds of Acheulian and Mousterian tools, 12 of them bearing fossils.

Heather Wilson and Lyall Anderson publish a paper describing the oldest land animal fossil yet discovered: Pneumodesmus newmani, a 428-million- year-old, centimeter-long millipede found by amateur fossil hunter Mike Newman.

M.-Y. Zhu and collaborators publish a description of munched trilobite parts inside another arthropod, confirming earlier suspicions that other animals snacked on the little water bugs.

Naama Goren-Inbar and her team announce the discovery of controlled fire use by hominids at a 790,000-year-old site in Israel, pushing the earliest known use of fire back 300,000 years from previous estimates.

Qingjin Meng and collaborators publish a description of an adult Psittacosaurus dinosaur associated with 34 juveniles, apparent evidence of parental care.

The British Museum begins an excavation project at Happisburgh in Norfolk. Over the next six years, researchers will uncover artifacts pushing back the earliest evidence of human activity at such a high latitude — 45 degrees — to perhaps as much as 950,000 years ago.

Using CT scans on femurs of the early hominid Orrorin tugenensis discovered in Kenya, Galik and collaborators push back the development of bipedalism in hominids to 6 million years ago (2 million years earlier than in Australopithecus anamensis).

X. Wang and Z. Zhou publish a description of the first known pterosaur egg containing an exquisitely preserved embryo. Though the egg is slightly smaller than the average chicken egg, the embryo sports a 27-centimeter wingspan. Several months later, Z. Zhou and F. Zhang publish a description of a Cretaceous bird embryo, the first found with feathers.

A team of Japanese researchers take the first photograph ever of a giant squid in the wild. Unfortunately, they rip off one of the poor creature's tentacles in the process.

The International Union of Geological Sciences adds a new period to the Earth's geologic timescale: the Ediacaran. Ranging from approximately 600 million years ago to 542 million years ago, it begins after the last Snowball Earth ice age and precedes the Cambrian. It's the first new geologic period designated in 120 years.

M.A. Whyte announces the discovery of a 330-million-year-old trackway of a 5-foot-long, six-legged water scorpion (eurypterid) that could walk on land while the first tetrapods tried to do the same thing. Two years later, Simon Braddy, Markus Poschmann and collaborators will announce the find of fossil claw from an 8-foot eurypterid.

Yaoming Hu, Jin Meng, Yuanqing Wang and Chuankui Li publish a description of two large carnivorous mammals from the Cretaceous, one of which appears to have the remains of a diminutive dinosaur in its stomach. These fossils overturn long-held notions that Mesozoic mammals were all rat-sized plebeians scurrying around dinosaur feet.

Yohannes Haile-Selassie and colleagues announce the find of a nearly 4- million-year-old hominid from Ethiopia, possibly the remains of Australopithecus anamensis.

Adrian Glover and Thomas Dahlgren announce the discovery of a new species of marine worm, discovered off the Swedish coast, that lives on whale bones on the sea floor. They name the species Osedax mucofloris.

Jean Moliner, Gerhard Ries, Cyril Zipfel and Barbara Hohn publish their findings on stressed plants that not only mutate at a greater rate, but also pass an increased mutation tendency to their offspring.

Andrew Z. Fine and Craig C. Mello share a Nobel Prize in Medicine for their discovery of RNA interference — gene silencing by double-stranded RNA.

Roger D. Kornberg was awarded a Nobel Prize in Chemistry for his studies of the molecular basis of eukaryotic transcription.

Jin Meng and collaborators describe a Mesozoic gliding mammal that pushes back the origin of mammalian flight by 70 million years, and suggests mammals maybe dabbled in flight earlier than birds.

Qiang Li and colleagues describe Castorocauda lutrasimilis, a Jurassic mammal that looked something like a mix between a beaver, otter, and platypus. Their discovery pushes back mammalian adaptation to an aquatic lifestyle by more than 100 million years.

The Research Council of Norway announces that oil drillers have struck a piece of dinosaur bone off the country's coast. At 1.4 miles below the North Sea, the bone fragment obtains the status of the world's deepest dinosaur.

Zeresenay Alemseged and collaborators publish a description of a 3.3- million-year-old partial skeleton from a juvenile Australopithecus afarensis from Ethiopia. The remains indicate that the australopithecene toddler walked upright and climbed trees.

Paleontologist Neil Clark suggests that some Loch Ness "sightings" may have been inspired by partial glimpses of traveling circus elephants taking dips in the lake.

Divers find a submerged cavern in the Yucatán and name it Hoyo Negro. The cavern contains the remains of a teenage female who likely died between 12,000 and 13,000 years ago.

Mario R. Capecchi, Sir Martin J. Evans, and Oliver Smithies share a Nobel Prize in Medicine for their discoveries of principles for introducing specific gene modifications in mice by the use of embryonic stem cells.

Fred Spoor, Meave Leakey and collaborators describe remains of Homo habilis and Homo erectus from the same rock layer a short distance apart. The finds suggest that the two species coexisted in the same area for up to 500,000 years, and that H. erectus probably did not descend from H. habilis as previously thought.

John Kappelman and collaborators announce the find of a 500,000-year-old hominid skull from Turkey showing signs of tuberculosis. The researchers argue that condition could be induced by a Vitamin D deficiency resulting from a dark-skinned individual migrating to an area with less sunlight.

Kate Trinajstic and collaborators announce the discovery of 380-million- year-old Australian fossil fish sporting fossilized muscle.

Xing Xu and collaborators describe Gigantoraptor erlianensis, a 25- foot-long, 3,000-pound, bird-like dinosaur from Inner Mongolia. The find runs counter to earlier assumptions that dinosaurs necessarily got smaller as they acquired more features resembling those of birds.

After studying grunting fish, Andrew Bass and colleagues report that the part of the brain controlling volcalization is extremely primitive, and propose that vertebrates evolved the ability to communicate through sound some 400 million years ago.

Based on studies of fossils and extant carnivores, Chris Carbone and collaborators suggest that sabertooth cats were sociable animals that hunted in packs.

Chinese and Brazilian researchers describe a sparrow-sized pterosaur from northeastern China. Although a juvenile, the pterosaur is no hatchling, and it's more mature than any of the smaller pterosaurs so far found. The researchers name the species Nemicolopterus crypticus meaning "hidden flying forest dweller."

Susan Evans, Marc Jones and David Krause describe a bowling-ball-sized fossil frog from Madagascar. Because the Cretaceous creature's closest living relative is in South America, the scientists posit a land link connecting South America, Antarctica and Madagascar. The frog is named Beelzebufo ampinga, translated loosely as "armored devil toad" or more loosely as "fossil frog from hell."

Gabriele Gentile and colleagues describe a previously overlooked pink iguana, referred to as "rosada," on the Galápagos Islands. The pink lizard species may represent the earliest divergence of land animals on the island chain that Charles Darwin made famous.

Elizabeth H. Blackburn, Carol W. Greider, and Jack W. Szostak share a Nobel Prize in Medicine for their discovery of how chromosomes are protected by telomeres and the enzyme telomerase.

Venkatraman Ramakrishnan, Thomas A. Steitz, and Ada E. Yonath share a Nobel Prize in Chemistry for their studies of the structure and function of the ribosome.

Anthony Martin and colleagues announce the discovery of three 106-million- year-old burrows in Australia that they identify as dinosaur burrows, perhaps used by the ancient reptiles to keep warm during the winter when Australia was closer to the South Pole.

Australian paleontologists announce the find of Zac, a plant-munching sauropod, on a sheep farm — the same sheep farm where paleontologists discovered Cooper, an armor-plated titanosaur, in 2004.

Chris Henshilwood and collaborators describe 13 engraved ochre artifacts from South Africa's Blombos Cave, some dating back 100,000 years. This discovery supplements earlier finds pushing back the advent of human artwork.

Erik Seiffert and coauthors argue that "missing link" Darwinius masillae described earlier in the year is not an ancestor of modern apes and monkeys but instead of modern lemurs and lorises.

Nicholas Conard and collaborators describe 35,000-year-old flutes, one nearly complete flute carved from bird bone, and flute fragments carved from ivory, discovered in Hohle Fels Cave in Ulm, Germany.