Scientists at the University of Copenhagen have become the first to reconstruct the nuclear genome of an extinct human being.

Woolly mammoths and prehistoric horses grazed on the North American plains for several thousand years longer than hitherto assumed.

A team of Swedish, Danish and British researchers says it used DNA to determine today's Scandinavians are descended from Stone Age immigrants. The researchers said their findings that involve both genetics and archaeology contradict the theory that Scandinavians are descended from the people who came to Scandinavia at the conclusion of the last ice age. The hunter-gatherers who inhabited Scandinavia more than 4,000 years ago had a different gene pool than ours, said Uppsala University Assistant Professor Anders Gotherstrom, who led the project with University of Copenhagen Professor Eske Willerslev. The scientists said they used DNA from Stone Age remains to investigate whether the practices of cultivating crops and keeping livestock were spread by immigrants or represented innovations on the part of hunter-gatherers. Obtaining reliable results from DNA from such ancient human remains involves very complicated work, said Uppsala University researcher Helena Malmstrom, who conducted the

Today's Scandinavians are not descended from the people who came to Scandinavia at the conclusion of the last ice age but, apparently, from a population that arrived later, concurrently with the introduction of agriculture.

In a new study published April 1 in the online, open-access, peer-reviewed journal PLoS ONE, ancient DNA (aDNA) is retrieved from various insect remains without destruction of the specimens.