The Human Genome Project is launched with the goal of sequencing all 3 billion base pairs of human DNA by 2005.

Mongolia invites the American Museum of Natural History to reinstate excavations in the Gobi desert.

Scott Wing of the Smithsonian Institution discovers the Big Cedar Ridge fossil plant site in Wyoming. The locality will become known as the Pompeii of Cretaceous plants.

Chicxulub crater is discovered in the Yucatán Peninsula, supporting the asteroid impact theory first suggested in 1980.

A team led by Tim White finds the first traces of a hominid fossil that will later be named Ardipithecus ramidus. Seventeen years later, the team will publish a detailed description of a 4.4-million-year-old, 120-centimeter-tall, nearly complete adult female, along with fossils from 35 other individuals. The team will argue that "Ardi" should supplant Lucy at the base of the hominid tree.

Ian Campbell and collaborators publish a paper pointing to the Siberian Traps, an area of massive volcanic activity, as the cause of the Permo- Triassic mass extinction 251 million years ago.

Paleontologists led by Jim Kirkland discover Utahraptor, a super-sized velociraptor that conveniently supports the super-sized velociraptors that will appear in the screen version of Jurassic Park a year later.

Suburban San Diego roadwork uncovers mastodon bones and broken rocks at what becomes known as the (Richard) Cerutti Mastodon site. Roadwork halts while paleontologist Tom Deméré examines the find. Twenty-five years later, Deméré, Cerutti and nine other researchers will contend that the site is evidence of human presence in North America 130,000 years ago.

Joe Kirschvink publishes "Late Proterozoic Low-latitude Glaciation: The Snowball Earth," a short book section in a specialized monograph. This snowball Earth hypothesis will attract little attention until expanded by Paul Hoffman and his collaborators several years later.

Kary Mullis and Michael Smith share a Nobel Prize in Chemistry, with Mullis cited for his contributions to the developments of methods within DNA-based chemistry and Smith for his fundamental contributions to the establishment of oligonucleiotide-based, site-directed mutagenesis and its development for protein studies.

Richard J. Roberts, and Phillip A. Sharp share a Nobel Prize in Medicine for their discoveries of split genes.

A calcite-encrusted hominid skeleton is discovered in a karst cave near Altamura, Italy. About two decades later, researchers will date the rock layers and test a scapula fragment, eventually concluding that the skeleton is probably 128,000 to 187,000 years old, and ranks among so- called "early Neanderthals."

Geology student Iwan Stossel stumbles across a nearly 400-million-year-old tetrapod fossil trackway on the island of Valentia, County Kerry, Ireland.

J. William Schopf publishes a description of microfossils of the Apex Basalt in Australia. His claims that they are 3.5-billion-year-old microbes that could photosynthesize and produce oxygen will later be challenged. One of his challengers, Martin Brasier, will coauthor a 2011 study on microfossils from a nearby outcrop, claiming that the 3.4-billion- year-old microbes fed off sulfur.

On an expedition in the Gobi desert, paleontologists from the American Museum of Natural History discover the skeleton of an Oviraptor dinosaur crouching over a nest of eggs, apparently incubating them in the same fashion as modern birds.

Roland Anderson and Jennifer Mather publish "Personalities of Octopuses" in the Journal of Comparative Psychology.

Anthropologist Ron Clarke finds previously overlooked foot bones, showing both ape and human qualities, from Sterkfontein. Future finds will associate these bones with a skeleton nicknamed Little Foot.

In what will later be named Chauvet Cave, French cavers discover 32,000-year-old paintings showing 400 animal images.

Edward B. Lewis, Christiane Nüsslein-Volhard, and Eric F. Wieschaus share a Nobel Prize in Medicine for their discoveries concerning the genetic control of early embryonic development.

Lee Berger and Ron Clarke publish an article in the Journal of Human Evolution arguing that the Taung child, discovered in 1924, may have been killed by a bird of prey.

Using "molecular clock" estimates of mutation rates, Greg Wray and collaborators hypothesize that metazoan phyla diverged from each other 1 billion years ago, or even earlier. In other words, they argue that metazoans existed hundreds of millions of years before the earliest metazoan fossils (about 600 million years old) yet found.

Alan Walker and Pat Shipman publish a description of advanced Vitamin A poisoning in a 1.7-million-year-old Homo erectus skeleton. They assert that it is evidence of both meat eating, caused by consuming the liver of a large carnivore, and sufficient sociability in Homo erectus to care for an ill and incapacitated individual.

Chen Pei Ji unveils Sinosauropteryx prima from Liaoning, China, the first feathered dinosaur discovered, at the Society of Vertebrate Paleontology's annual meeting. Fourteen years later, a team of Chinese and British paleontologists will argue that this animal had a striped tail, a reddish color alternating with white, based on pigment-rich microscopic spheres in the fossilized feathers.

The roughly 9,000-year-old Kennewick Man skeleton is found in the northwestern United States. Craniometric analysis initially suggests an affiliation to Ainu and Polynesian groups. Better DNA sampling methods will finally allow genetic analysis nearly 20 years later, and that will indicate a relationship closest to modern Native Americans.

Tim White's team discovers horse, antelope and other mammal bones with cut marks from stone tools — evidence of tool use 2.5 million years ago.

A team of archaeologists finds evidence of human occupation 14,000 years ago at Monte Verde, Chile, pushing back the arrival date of humans in the Americas.

Excavations near Koblenz in northern Germany turn up a Neanderthal skullcap, estimated at 170,000 years old, that was apparently used as a bowl.

Paleontologist Karen Chin receives a 17-inch coprolite excavated in Saskatchewan. Estimated at 65 million years old and full of crunched bone, it is likely the calling card of a T. rex.

Paleontologist Paul Sereno discovers the delicate Darth Vader-like skull of a dinosaur he will later name Nigersaurus taqueti and nickname the "Mesozoic Cow."

Two 5-foot-long Humboldt squid in the Sea of Cortez "mug" a diver working on a PBS documentary, making off with the gold chain hanging around the diver's neck, and demonstrating that Humboldt squid have bad manners but good taste.

Andrew Parker publishes a paper suggesting that some Cambrian animals (Wiwaxia, Canadia and Marella) developed flickering displays of iridescent color at about the same time that eyes evolved.

Aterian artifacts (named for stone tools discovered in Algeria in 1917) are estimated at 70,000 years old at sites in Libya. Over the next dozen years, the age of artifacts found at various sites in northern Africa will be pushed back to at least 110,000 years old.

Xiao, Zhang and Knoll describe fossilized animal embryos in Nature. Li, Chen and Hua simultaneously describe embryos in Science. The fossils all come from the Doushantuo phosphorites in southern China, and all are estimated to be about 570 million years old, making them the oldest fossil embryos so far discovered. Nine years later, however, Bailey and collaborators will challenge this interpretation, arguing the "fossil embryos" could just as easily be large bacteria. That challenge will be answered by the announcement of fossil embryos inside egg cysts.

Paul Hoffman, Alan Kaufman, Galen Halverson and Daniel Schrag publish a Neoproterozoic snowball Earth theory arguing that in the late Precambrian, the Earth underwent global glaciations followed by extreme greenhouse conditions, spurring the evolution of multicellular life forms.

Pierre-Jean Texier and colleagues begin studying etched ostrich shells from Diepkloof Rock Shelter in Western Cape, South Africa. Eleven years later, they will argue that the artifacts, numbering roughly 280, show evidence of graphic communication dating back 60,000 years.

Chinese paleontologists discover an exceptionally well-preserved feathered dinosaur, probably a juvenile dromaeosaur. Citing the confusion caused by language barriers and jet lag, the paleontologists' American collaborators nickname the fossil "Dave the fuzzy raptor," after a character alluded to in a Cheech and Chong routine. This fossil will be assigned to the genus Sinornithosaurus. (The next fuzzy discovery will be nicknamed "Chong.")