Thursday, December 30, 2010

Hot News from the Boneyard

We bone-watchers have been having lots of fun lately. And in the last few days we get two announcements together, which might or might not mean something, nothing or a great deal. The expansion of man and his relatives around the world has any number of fascinating stories to tell, and we are only just beginning to hear them. Too many are gone for ever, sadly, because so much of the Earth doesn't preserve its bones, but the tales that have lived will one day be harvested and we will sit enthralled as they tell us who we were.

We already knew something about Denisova, where a few months ago a bone from a little finger and a tooth were sequenced, and more or less determined as an Eastern neanderthal. But that was with mtDNA, which is passed down the female line and gives less, or at times less accurate, information. The nuclear DNA has now been sequenced and the interpretation is that it's from a distinct type of hominid, neither sapiens nor neanderthal, hitherto unknown.

So, 40,000 years ago in the Altai mountains (emblematic, they gave their name to the Altaic language family, which might not exist, but if it does it includes Turkish, Mongolian and Kyrgyz) in southern Siberia (which is an odd way to describe it; I thought the point of Siberia was that it was all north, but apparently not).

So it seems there were three hominids living close together at approximately the same time. It's the coetaneous business that wrenches the paradigms a bit. Also the fact that whoever these creatures/people were, they must have arrived by a more complex route than wandering out of Africa through Israel. At least a different route.

So are they descended from a population of heidelbergensis that moved East around 600,000 years ago? And what happened to them? Well, the second question is easy to answer. They were mortal. They died. They interbred with Homo sapiens in the area, however, and some of their DNA is preserved, at least in some people from Papua New Guinea. Who woulda thunk it, indeed?

Then we get this story from Israel. The newspapers are saying that the cradle of humanity might have been the Holy Land, rather than East Africa. Well, it may sell newspapers, but it's not what the team is actually saying.

The Qesem cave near Tel Aviv has produced a few teeth which look like Homo sapiens but have been dated at 300-400,000ka, twice as old as the earliest known 'us' (from Omo in Ethiopia). The dating looks sound enough, but the attribution to sapiens is very uncertain. In fact they don't attribute it to Hom sap at all, but they do say that the teeth are more similar to teeth from Skhul/Qafzeh, which are believed to be human, than to Neanderthals.

The comments of the team are based exclusively on the morphology of the teeth; no genetic material has yet been analyzed (or even recovered, as far as I can see). If it is, however, and they do turn out to be very old Hom sap, then it's going to get very interesting trying to work it all out. Fortunately, I'm just a spectator in all this, I don't have to think, only enjoy the show.

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