Saturday, May 22, 2010

Neanderthals Again

The discovery that non-Africans derive a small percentage of their DNA from Neanderthals is extremely important to our understanding of our recent history. Of great symbolic importance (at least to me) is the fact that Homo neanderthalensis was almost certainly not a distinct species. This question has been the subject of much debate over the years, and appeared to have been settled when the mtDNA was sequenced a few years ago. But mtDNA is haploid and doesn’t contain the same information as nuclear DNA, and the sequencing of the complete genome shows a certain number of characteristic mutations which are not found in any African population but are found in people from Europe, and Asia. This means that their must have been mixing (reproduction) between Neanderthals and modern humans after we left Africa, which is believed to have happened about 60-100,000 years ago.

The upshot of this is likely to be that Neanderthals are no longer be classified as a separate species, and will be returned to Homo sapiens neanderthalensis, as some taxonomists had them until fairly recently. It isn’t like Pluto ceasing to be called a planet (in any case they’ll have to indoctrinate a new generation before that idea gets accepted). Pluto’s classification was changed not because we learnt anything new about Pluto, but to keep the labels tidy. We have learnt something new about the Neanderthals, something with important philosophical implications.

I liked the idea that, almost within recorded history, another intelligent, rational creature shared the planet with us, and even lived alongside us in certain places. A creature capable of rational analysis, industry, and presumably symbolic behaviour, including speech. It allowed me to speculate on how these species would have seen each other, and how it would have altered their attempts to understand the world, and their own identity, to have regular contact with something that was like them in too many ways for them to consider themselves unique, as we do, but was sufficiently different to obviously not be them. I discussed this (rambled on would be another way of putting it) here and here.

The essential point was that 40,000 years ago, at least some groups of European and Asian humans would not have had the instinctive feeling that they were obviously unique and special, and so they would not have sought to explain it and built upon it the way others, including us, are used to doing. It must have affected their concept of right and wrong, their attempts to explain their own origins, the way they accepted, or avoided accepting, their own mortality, and it would have been fascinating to learn about systems of belief from that time. It still is fascinating to speculate on what impact it might have had.

But it seems that they didn’t see the Neanderthals as anything more than another tribe, not exactly them, but to like them to be a threat to their uniqueness. Ah well, there’s still Flores, if anything certain ever comes out of the work there.

As usual, for real information about this subject, try John Hawks, and the original papers are here and here.


Perry de Havilland said...

I share your fascination on this subject and oh how I wish things had transpired to allow them to hold on long enough for literate man to have recorded their words.

CIngram said...

Thanks for dropping by.

It is exactly the thought that they, or some other cousin species (like floresiensis, or even, why not, erectus), might so easily have survived alongside us into historical times that first got me interested in the subject, and I've been hooked ever since.