http://www.bbc.co.uk/news/science-environment-43115485
https://www.theguardian.com/science/2018/feb/21/arrival-of-beaker-folk-changed-britain-forever-ancient-dna-study-shows
Interesting, thanks :)
disease is a possibility although one wonders how such a widespread 'overunning' of the gene pool could take place so completely
Disease is an obvious factor. A disease which was endemic among the newcomers but spread slowly because of their dispersed culture could go like wildfire through a population used to assembling people together in masses to celebrate events.
A weakened population could more easily be displaced from the prime agricultural land and set on a declining path.
But, without more evidence to fine tune the diffusion/migration model, be difficult to say anything hard and fast.
From what we know of more recent examples (such as the replacement of the population of the Americas by Europeans and others) it's a combination of many causes - disease, violence, displacement and competition all have a part to play. Climate changes would exacerbate the effects of displacement particularly (by taking the most productive land).
Very interesting.
One of the reasons disease was so devastating in the New World was its populations isolation from the immunity developed to trans species diseases by the incomers. Neolithic Britain was not isolated, in fact the sea ways were busy and the advance of the Beaker folk relatively slow. Also the original population seem to have been mixed stock farmers not too different from the Beaker Folk. Given that I'd expect trans species disease immunity to have already developed. Disease could have played a role but it would not be my first choice as the decisive agent of population change.
I hope we find out more.
I'm a great believer in the effect of disruption on native populations. Hunter gatherers have lives that run to a rythm , in winter we go to the caves , fish by the river and eat the meat we smoked in the summer...in summer we folliw the aurochs to their summer pastures and kill a few. When someone new arrives they disrupt the pattern of life and likely the pattern of breeding. A transhumance lifestyle only needs interrupting for a few seasons to cause a steep real population decline. The Beakers might only advance slowly, but if they disrupt the hunters each time they will gradually destroy them.
Roy
But the Beakers (a whole tribe of ginger-haired figures in lab coats?) are displacing farmers. Technologically, they aren't much in advance of the natives. They are also not warriors falling on the peace-loving hippies of Stonehenge - Neolithic violence is well attested. So, we must look for things that might explain why the natives were swept aside with limited interbreeding. Disease is one possibility. Failure of the natives to adapt to climate change, with the Beakers being better adapted? Implossion of native society due to external and internal stresses previously mentioned leading to Beakers opportunistically occupying a semi-deserted landscape and able to overcome the remnants of native society?
Easter Island scenario? Unlikely but....?
Quote from: Holly on March 02, 2018, 02:16:45 PM
Easter Island scenario? Unlikely but....?
Wasn't that based on failure to sustainably exploit resources? The natives in Britain had plenty of space to expand into, unless they were self-limiting in what type of land they could utilise and used it all up. Given that they settled the whole of the British Isles it seems unlikely.
Another possible factor would be a murrain or animal epidemic which the newcomers animals carried but were resistant to. If they were heavily pastoral, it would be pretty catastrophic. The plausibility of this being an agricultural question, we should summon Jim.
The latest thinking I have heard about Easter Island is that the population adaoted to the changes they caused quite well and that collapse did not occur until after the first contact with Europeans and the diseases they brought. Even quite mild diseases in a European context could be deadly to thise who had lived in isolation.
It would be remarkable for there nor to be intermarriage, so even if disease had carried off three quarters of the natives one would expect mixing. Also if the beakers move onward slowly the population further West would bounce back.
One thing that does keep populations exclusive is religion. Perhaps the two populations were so inimical to one another that mixing was a form of pollution?
Roy
Quote from: aligern on March 02, 2018, 03:43:49 PM
It would be remarkable for there nor to be intermarriage, so even if disease had carried off three quarters of the natives one would expect mixing.
I think the study suggested 10% pre-Beaker DNA (though its not a big sample). So some intermarriage can be allowed for, or other integration.
Quote
One thing that does keep populations exclusive is religion. Perhaps the two populations were so inimical to one another that mixing was a form of pollution?
Roy
Well, their different funerary practices would suggest religious differences but how deep or exclusive these were we'd be guessing.
Quote from: Erpingham on March 02, 2018, 02:28:07 PM
Quote from: Holly on March 02, 2018, 02:16:45 PM
Easter Island scenario? Unlikely but....?
Wasn't that based on failure to sustainably exploit resources? The natives in Britain had plenty of space to expand into, unless they were self-limiting in what type of land they could utilise and used it all up. Given that they settled the whole of the British Isles it seems unlikely.
Another possible factor would be a murrain or animal epidemic which the newcomers animals carried but were resistant to. If they were heavily pastoral, it would be pretty catastrophic. The plausibility of this being an agricultural question, we should summon Jim.
it is possible, but the equivalent of smallpox hitting a a naive human population is at least as possible
initial contact with new Beaker folk, disease outbreak followed by westward migration/segregation and follow up of occupation of vacated lands
Quote from: Holly on March 02, 2018, 08:29:03 PM
initial contact with new Beaker folk, disease outbreak followed by westward migration/segregation and follow up of occupation of vacated lands
According to the celebrated authority wiki, the population of Mexico fell from 25-30 million to 3 million in fifty years.
Quote from: Jim Webster on March 02, 2018, 08:43:38 PM
Quote from: Holly on March 02, 2018, 08:29:03 PM
initial contact with new Beaker folk, disease outbreak followed by westward migration/segregation and follow up of occupation of vacated lands
According to the celebrated authority wiki, the population of Mexico fell from 25-30 million to 3 million in fifty years.
that is significant and more importantly shows a parallel occurrence which could account for this
Quote from: Jim Webster on March 02, 2018, 08:43:38 PM
According to the celebrated authority wiki, the population of Mexico fell from 25-30 million to 3 million in fifty years.
I believe I've seen estimates of more radical decline, but they weren't in the book I thought they were from.
But (central and southern) Mexico was a densely populated place with relatively good communications: good conditions for epidemics to spreak. Would Neolithic Britain have been as vulnerable?
In the non mountainous areas, I suspect there was a reasonable network of communication with neighbours and even in the uplands there would have been contact. If the Mexico example took 50 years, I am sure that kind of timeframe is also possible for Britain
Quote from: Holly on March 02, 2018, 08:29:03 PM
initial contact with new Beaker folk, disease outbreak followed by westward migration/segregation and follow up of occupation of vacated lands
I'm not sure about the migration - we'd need more samples that showed pre-Beaker DNA more prevalent in the West to prove it. Segregation/marginalisation of remnants with some violent removals and some integration would do it, if the disease was virulent enough. What disease would be speculation but DNA has been extracted from teeth to prove the Black Death was Y. Pestis so that might be a route to test the hypothesis.
Quote from: Holly on March 03, 2018, 07:58:09 AM
In the non mountainous areas, I suspect there was a reasonable network of communication with neighbours and even in the uplands there would have been contact. If the Mexico example took 50 years, I am sure that kind of timeframe is also possible for Britain
A naive population is still naive, it might have taken longer, or with less people it might not have taken them as long to die out. In theory you might find isolated populations on islands in the far north and west could have hung on, but the problem here is that archaeology cannot give us anything like the detail
no, the best evidence is datable DNA