Mysterious 'Denisovan' cavemen had sex with humans from Borneo to the Philippines



Species discovered last year in Siberia spread DNA across Southeast Asia

DNA of 'archaic' Denisovans is like a 'dye' you can use to trace migrations

'Two generations' of early humans spread through Southeast Asia

Present-day New Guineans carry a trace of ancient history in their DNA - their genetic grandparents included Denisovans, a 'third species' of early man other than humans and Neanderthals, who walked on two legs and appeared just as man was developing the ability to use tools.



The distinctive pattern of Denisovan DNA seems to have spread far further than originally thought - and proved that Asia was settled in two 'waves', the first related to Denisovans, and the second migration consisting of relatives of the East Asians who are now the main population of the area.

This tooth, thought to have come from a five to seven-year-old child, was found in the same cave, and was the first evidence of the existence of Denisovans - now thought to be a crucial 'key' to tracing man's evolution

Denisovan DNA has proved to be a hugely useful tool in analysing early man - and Denisovans interbred prolifically with other early human populations throughout the regions.



According to David Reich, a professor of genetics at Harvard Medical School, 'Denisova DNA is like a medical imaging dye that traces a person's blood vessels. It is so recognizable that you can detect even a little bit of it in one individual.



'In a similar way, we were able to trace Denisova DNA in the migrations of people. This shows the power of sequencing ancient DNA as a tool for understanding human history.'

It's speculated that while Neanderthals (pictured) migrated into Europe 300,000 years ago, 'Denisovans' went East and colonised Asia

The human 'family tree' is far more complex than first thought - and Denisovan DNA, first found in a child's finger bone in a cave in Siberia last year, is a crucial 'key' to unravelling prehistory.



Contrary to previous ideas of prehistory, where humans fought with, and stayed separate from our ancestors, interbreeding seems to have been common since early humans left Africa in two groups between 300,000 and 400,000 years ago - one group forming Neanderthansl



The study demonstrates that contrary to the findings of the largest previous genetic studies, modern humans settled Asia in more than one migration.



The cave in Siberia where the first evidence of Denisovans was found - the species interbred with homo sapiens more prolifically than Neanderthals did

The patterns the researchers found, revealed in the American Journal for Human Genetics , can only be explained by at least two waves of human migration: the first giving rise to the aboriginal populations that currently live in Southeast Asia and Oceania, and later migrations giving rise to relatives of East Asians who now are the primary population of Southeast Asia.

The study also provides new insights about where the ancient Denisovans lived. According to Mark Stoneking, a professor at the Max Planck Institute who is senior author of the paper, Denisovans must have inhabited an extraordinarily large ecological and geographic range, from Siberia to tropical Southeast Asia.



'The fact that Denisovan DNA is present in some aboriginal populations of Southeast Asia but not in others shows that there was a mix of of populations with and without Denisova material more than 44,000 years ago,' he said. 'The presence of Denisovan genetic material in some but not all the groups there can most easily be explained if Denisovans lived in Southeast Asia itself.'