Discussions on the history and historiography of Australia's New England

Tuesday, May 01, 2018

Cheddar Man revisited - More hype and complexity

Back in 2007 (Continuity in the face of great change - the case of Cheddar Man 5 April 2007) I reported on DNA results from  Bryan Sykes of Oxford University on Cheddar Man, the human skeleton of a Mesolithic hunter-gatherer found in 1903 in Gough's Cave in the English Cheddar district.

I was reminded of this last night while watching a British National History Museum video on the latest DNA analysis of Cheddar Man. I therefore went back and found the earlier post. Boy, do I feel a little silly.

To explain this, this is an excerpt from what I wrote at the time:
When I first studied what was then called English history, there is another interesting story in the use of this name, I was struck by the constant waves of invasion. I suppose I assumed, I know that I assumed, that this meant the replacement of one group of people by another, essentially extinguishing the earlier group. We now know that this is not true because of the rather remarkable case of Cheddar Man. 
In 1903 the complete skeleton of a human male was excavated from Gough's Cave in Cheddar Gorge, Somerset, hence the name Cheddar man. We now know that the remains date to approximately 7150 BCE, at least three thousand years before the advent of agriculture in the area. It appears that he died a violent death, perhaps related to the cannibalism practiced in the area at the time. 
In the late 1990s, Bryan Sykes of Oxford University sequenced the mitochondrial DNA of Cheddar Man with DNA extracted from one of Cheddar Man's molars. He then, and this is something that I suspect that I would have regarded as a gimmick, tested the DNA of a sample of twenty residents of the modern Cheddar village. He found two exact matches plus one very close match. 
Leaving aside the excitement of the two school children who gave the exact match and probably have the oldest scientifically established family tree in the world, the results show that Cheddar Man's family continued to reside in the same locality for perhaps 350 generations, surviving through all the invasions and changes. 
It also made me wonder about the role that DNA testing might play if we could do it in the appropriate way in extending our knowledge of Australia's Aboriginal past. 
We know that Aboriginal populations were not static, but shifted over time. We do not really understand those shifts.
I was right, of course, on the potential role that DNA tests might might play in increasing our understanding of the deep Aboriginal past, but I seem to have really jumped to uncritical conclusions on Cheddar Man. I also did not give my own sources in that original post, although it was based on news reports.

The results of the latest research is summarised in these stories:
The results have attracted major media attention because the DNA results suggest that Cheddar Man was dark skinned, More precisely, the probability is that he was dark skinned. He was also lactose intolerant. The Museum summary states in part:  .
Modern-day British people share approximately 10% of their genetic ancestry with the European population to which Cheddar Man belonged, but they aren't direct descendants. 
Current thinking is that the Mesolithic population that Cheddar Man belonged to was mostly replaced by the farmers that migrated into Britain later.  
Now how do we relate this to the conclusions in my earlier post?

Well, first of all, considerable doubt has been cast on Professor Sykes original results. The new results are consistent with the earlier picture of multiple invasions. They also, I think, provide hints at the merging of populations over time. Beyond that, I am not sure!

The National Museum video, though, is worth watching as an introduction to the painstaking world of research and the results that can arise.For my part, I will leave the original post standing because it represents part of the evolution of my own thinking over eleven years, but add a qualification and link to this post.

Comments that might elucidate and educate me are very welcome! .

2 comments:

Johnb said...

I find this to be such a huge canvas Jim spread over considerable time and space. The results from dna sampling are only adding to the complexity involved. My touch base for grasping the significance of dna results start out from the work of Cavalli-Sforza.
Quote.
Percentage genetic distances among major continents based on 120 classical polymorphisms
Europe America East Asia Oceania
America 9.5
East Asia 9.7 8.9
Oceania 13.5 14.6 10
Africa 16.6 22.6 20.6 24.7
Further information: Human genetic variation
According to Cavalli-Sforza's work, all non-African populations are more closely related to each other than to Africans; supporting the hypothesis that all non-Africans descend from a single old-African population. The genetic distance from Africa to Europe (16.6) was found to be shorter than the genetic distance from Africa to East Asia (20.6), and much shorter than that from Africa to Australia (24.7).
end quote.
My intuitive guess is that the original old African population would be Homo erectus, the most successful hominid population by far. Homo erectus was around long enough and spread widely enough for evolution to have worked its magic to give us Denisovians, Florienis and all stops in between. I also think insufficient credence has been given to hominid abilities to cross water barriers for both colonisation of new territories and trading. When you look at the distribution achieved by H.erectus they had to have been able to cross significant bodies of water and it is unlikely that skill was lost any more than tool making and fire were lost. A recent piece of work has evidence that Neanderthals had this capacity.
http://www.sciencemag.org/news/2018/04/neandertals-stone-age-people-may-have-voyaged-mediterranean
We know that one of their last redoubts was Gibraltar and if they could navigate to the Greek Islands then North Africa was also likely. Which brings us to our Mesolithic Cheddar Man and the Atlantic Conveyor where people’s moved post glacial North along the Atlantic Coast from Refugia in North Africa and Iberia. The evidence from Arabia, South Asia, South East Asia, Australasia, North East Asia and Oceania all indicates a sustained human capacity to cross significant bodies of water. Something else I don’t think has been given anywhere near the prominence it deserves are the evolutionary changes to the birth canal that must have co-evolved with the changes in brain volumes. As the birth canal changed it must have also brought significant social/cultural change as birthing moved from a souls activity to an assisted one, such a profound change.
http://rstb.royalsocietypublishing.org/content/370/1663/20140065.long
I have wandered a bit Jim but hope there is sufficient continuity to your original piece.

Jim Belshaw said...

There is, John. Connection that is.

I think that I agree with you, although I didn't properly understand the numbers, just the pattern. I think that we need to wait for more information on all this.