The island groups of Melanesia – which includes Papua New Guinea, Fiji and the Solomon Islands and others – are geographically cut off by the Pacific Ocean, with their DNA providing a unique window into how human ancestors spread across the region.
The latest research, presented at a meeting of the American Society for Human Genetics in Vancouver, bolsters previous findings that there may be another strand to the story of modern humans, with multiple groups of prehistoric human interbreeding.
One of the problems has been in finding the ancient specimens to put alongside, and constrain, these genetic estimates.
The ice provides a platform from which to hunt ringed, and other, seals.
A single finger bone and a few teeth found in a cave in Russia revealed another branch of the family tree, the Denisovans, also left their genetic calling card in modern humans, accounting for as much as four per cent of people’s DNA in Melanesia.
Native people from Papua New Guinea in Melanesia are believed to owe between two and four per cent of their DNA to Denisovans and carry less Neanderthal DNA than other Asians.
"With something like polar bears, to make an identification you've got to have a skull or a lower jaw - they've got very reduced teeth, rather surprisingly, and you've got to see that.
So I was interested to learn that [Ingolfsson's group] has that." Hidden Arctic Building up a more detailed picture of the ancient history of polar bears will be challenging, though.
Age 'confidence' "We have this specimen that confirms the polar bear was a morphologically distinct species at least 100,000 years ago, and this basically means that the polar bear has already survived one interglacial period," explained Professor Ingolfsson.