Friday 23 September 2011

Dinner with the Denisovans

And maybe a little more than dinner in a few cases.

I linked a couple of news stories to the Mr Wood's Fossils Facebook page today which are about the movement of humans across the globe. One was about how DNA studies shed a little light on how aboriginal Australians made their way there, and when. The other was a little more general, and concerned the gradual population of Asia with Homo sapiens.

When we humans spread ourselves around, it was eventually at the expense of our closest relatives. Neanderthal is the most famous non-human hominin to have been been out-competed to extinction, but let's not forget old Uncle erectus and Auntie Denisova. Who? Not much is known of the Denisovans. In fact, only a bit of finger bone and a tooth. It's thought they were part of a migration from Africa between that of the Homo erectus and modern humans, and the mitochondrial DNA results of the bone analysis suggest a common ancestor with both the Neanderthal and us at about 1 million years ago, then with the Neanderthals alone at a later date. So - once split, the Denisovans toddled off across Asia and made themselves at home.We know they lived in the Altai Mountains of Siberia around 40,000 years ago - that's where/when the fossils are from - but they probably were reasonably widespread.

They would have lived alongside both Neanderthals and humans, and those first groups of humans that passed through Asia on their way to Indonesia, Australia and points Antipodean show a higher percentage of shared DNA with the Denisovan line than those that came along later. Some level of interbreeding went on with the locals as these migrations passed through.

Anyway - just a little more to add to the storyline. There are a few sites that illustrate the human migration pretty well, though keeping these up to date must be a constant task. Have a look at these - The Bradshaw Foundation's Journey of Mankind, and the Genographic Project's Atlas of the Human Journey. It's far easier to understand when there's a map and a big arrow, I think.

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