Cro-Magnon hunter in Magdalenian era. Picture: J. Augusta, Z. Burian

SCIENTISTS have concluded ground-breaking tests on 45,000-year-old remains found in Siberia and re-written the history of mankind's expansion across the planet.

A team of 28 international experts reconstructed DNA extracted from a fossil thighbone recovered from the banks of the Irtysh River, near Ust-Ishim village in Omsk, six years ago.

Their analysis of the man's genome, which was the oldest genetic record ever obtained, provided a new theory on how humans moved east from Africa into what is now Russia. It also helped pinpoint a period when the earliest humans interbred with their Neanderthal cousins.

Previous estimates had thought this took place anywhere between 37,000 and 86,000 years ago, but the new data has narrowed this down to between 52,000 and 58,000 years ago.

Dr Yaroslav Kuzmin, a senior fellow at the Sobolev Institute, and one of the scientists involved in the research, told: 'Genome comparisons show that the man lived close to the moment of division of the early modern homo sapiens population into two groups, migrating from Africa to Eurasia.

'DNA data shows that the Ust-Ishim individual has no direct descendants among the modern populations of Eurasia.'

45,000-year-old human bone found in 2008 in Ust-Ishim. Pictures: Sergey Melnikov, Yaroslav Kuzmin

The 33cm-long human bone was found in 2008 by Nikolay Peristov, a historian from Omsk, who had been examining the muddy banks of the Irtysh River for signs of mammoth fossils.

Two years later tests by Siberian scientists showed it belonged to a man and was at least 10,000 years old, but to determine its age a tiny 1g sample was sent to Oxford University in the UK.

Experts from the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, were also introduced to the research to utilise their skills in the study of ancient DNA.

It was eventually confirmed the remains were about 45,000 years old, and the oldest ever found in the world. Two years ago it also emerged the bones held DNA fragments, allowing further analysis to take place.

Among the first results of the new study was that the remains belonged to a man who had larger amounts of Neanderthal DNA than the population living today in Eurasia. That meant the man lived soon after the first interbreeding of Neanderthals and our direct ancestors.

It is thought humans appeared in Africa about 200,000 years ago and research has previously stated that they expanded through the Middle East into the Old World. But the Siberian man's genome suggests his descendants lived after this exodus, but before they started heading east into Asia.

Omsk historian Nikolay Peristov (top). Bank of the Irtysh river near villages Panov and Ust-Ishim (bottom). Pictures: Sergey Melnikov, Yaroslav Kuzmin

One of the more interesting conclusions is the fact that the bone showed homo sapiens lived further north and east than previously believed, remarkable given the harsh climate in the centre of Western Siberia. Chemical ratios in the remains indicated the man would have lived on berries, nuts, vegetables, meat and fish.

A total of 28 scientists from 19 countries around the world worked on the latest research, which was published on Wednesday in Nature magazine.

Russia was represented by Siberian experts Sergei Slepchenko and Dmitry Razhev, from Tyumen, Yaroslav Kuzmin, from Novosibirsk, and Alexey Bondarev and Nicholay Peristov, from Omsk.