ANCIENT HUMANS KNOWN AS THE DENISOVANS INTERBRED WITH MODERN HUMANS WHO WERE ON THEIR WAY TO AUSTRALIA AND NEW GUINEA

A team of scientists are now suggesting that the Denisovans, an ancient human species that lived concurrent with Neanderthals and early modern humans, may have successfully crossed Wallaces Line, one of the world's largest biogeographic marine barriers in Indonesia, subsequently interbreeding with early modern humans who were on their way to Australia and New Guinea.

In 2010, a small bone fragment of a finger bone was discovered in Denisova cave in the Altai Mountains of Asia. Later genetic analysis indicated that it belonged to a heretofore unknown ancient human species, named Denisovans,and that their DNA is still present in native populations of Australia, New Guinea and surrounding regions. There is a distinct, and puzzling, absence of the DNA in Asian populations.

Now, as published in a Science opinion article, Alan Cooper of the University of Adelaide in Australia and Chris Stringer of the Natural History Museum in the UK are suggesting that the DNA presence could be the result of the Denisovans crossing over the deep oceanic marine barrier of Wallaces Line, a biogeographic gap that is so significant that it defines the division between European and Asian mammals on its west and marsupial-dominated Australasia on its east.

"The conclusions we've drawn are very important for our knowledge of early human evolution and culture," says Stringer. "Knowing that the Denisovans spread beyond this significant sea barrier opens up all sorts of questions about the behaviors and capabilities of this group, and how far they could have spread."

"The key questions now are where and when the ancestors of current humans, who were on their way to colonize New Guinea and Australia around 50,000 years ago, met and interacted with the Denisovans," says Professor Cooper.

Source: Adapted and edited from a University of Adelaid Press Release.
http://popular-archaeology.com/issue/09012013/article/ancient-human-crossed-ocean-barrier