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The gateway between the Atlantic and Pacific at the bottom of the globe opened up 41 million years ago, according to a study of old fish teeth. The research in Science pushes back the date of the forging of Drake Passage to twice as long ago as once thought. US geologists believe it kick-started the ocean current that swirls around Antarctica, helping to bring about a dramatic cooling effect. The continent was transformed from lush forest to the icy landscape of today.

NEW YORK (AP) -- Scientists have caught a fossil fish in the act of adapting toward a life on land, a discovery that sheds new light one of the greatest transformations in the history of animals. Scientists have long known that fish evolved into the first creatures on land with four legs and backbones more than 365 million years ago, but they've had precious little fossil evidence to document how it happened. The new find of several specimens looks more like a land-dweller than the few other fossil fish known from the transitional period, and researchers speculate that it may...

Astrobiology sounds like the stuff of lava lamps and Jetsons reruns. Yet seven years after NASA launched a formal astrobiology research program, scientists of every stripe — geologists, biologists, chemists, paleontologists, oceanographers and astronomers — have rallied to the quest. They've spent as much as $65 million a year trying to solve a mystery that has underpinned religion and inspired thinkers from Seneca to Carl Sagan: How did life on the lonely Earth begin? And is Earth really the only source of life in the universe? With the help of modern tools such as the genome, high-powered computer modeling and...

Scientists have pieced together part of the genetic recipe of the extinct woolly mammoth. The 5,000 DNA letters spell out the genetic code of its mitochondria, the structures in the cell that generate energy. The research, published in the online edition of Nature, gives an insight into the elephant family tree. It shows that the mammoth was most closely related to the Asian rather than the African elephant. The three groups split from a common ancestor about six million years ago, with Asian elephants and mammoths diverging about half a million years later. "We have finally resolved the phylogeny of...

A supernova blast 41,000 years ago started a deadly chain of events that led to the extinction of mammoths and other animals in North America, according to two scientists. If their supernova theory gains acceptance, it could explain why dozens of species on the continent became extinct 13,000 years ago.

Scientists have extracted and decoded the DNA of a cave bear that died 40,000 years ago. They plan to unravel the DNA of other extinct species, including our closest ancient relatives, the Neanderthals. But they say the idea of obtaining DNA from dinosaurs, depicted in the film Jurassic Park, remains science fiction. It is highly unlikely that viable genetic material will ever be recovered from fossils that are hundreds of millions of years old. But the scientists hope to be able to sequence the DNA of ancient humans, which lived at the same time as cave bears, raising the prospect...

DNA project to trace human steps By Paul Rincon BBC News science reporter A project spanning five continents is aiming to map the history of human migration via DNA. The Genographic Project will collect DNA samples from over 100,000 people worldwide to help piece together a picture of how the Earth was colonised. Samples gathered from indigenous people and the general public will be subjected to lab and computer analysis to extract the valuable genetic data. Team leader Dr Spencer Wells calls the plan "the Moon shot of anthropology". We see this as part of the commons of our species...