Mysterious Archaic Cavemen – Denisovans – Were Relatives To Neanderthals And Humans

MessageToEagle.com – Ancient human relatives — the Denisovans crossed the famous Wallace’s Line, one of the world’s biggest biogeographic barriers which is formed by a powerful marine current along the east coast of Borneo, say researchers.

Three years ago the genetic analysis of a little finger bone from Denisova cave in the Altai Mountains in northern Asia led to a complete genome sequence of a new line of the human family tree — the Denisovans.

Since then, genetic evidence pointing to their hybridisation with modern human populations has been detected, but only in Indigenous populations in Australia, New Guinea and surrounding areas.
In contrast, Denisovan DNA appears to be absent or at very low levels in current populations on mainland Asia, even though this is where the fossil was found.

“In mainland Asia, neither ancient human specimens, nor geographically isolated modern Indigenous populations have Denisovan DNA of any note, indicating that there has never been a genetic signal of Denisovan interbreeding in the area,” says Professor Cooper, Director of the University of Adelaide’s Australian Centre for Ancient DNA.

The only place where such a genetic signal exists appears to be in areas east of Wallace’s Line, according to researchers.

“The recent discovery of another enigmatic ancient human species Homo floresiensis, the so-called Hobbits, in Flores, Indonesia, confirms that the diversity of archaic human relatives in this area was much higher than we’d thought,” says Professor Stringer, Research Leader in Human Origins, Natural History Museum, in London.

“The morphology of the Hobbits shows they are different from the Denisovans, meaning we now have at least two, and potentially more, unexpected groups in the area.

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

Intriguingly, the genetic data suggest that male Denisovans interbred with modern human females, indicating the potential nature of the interactions as small numbers of modern humans first crossed Wallace’s Line and entered Denisovan territory.

Paper.

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