9000 BP

The DNA of modern Europeans carries a ‘marker’ section that appears to have come from no-where - a finding that New Scientist described as ‘bizarre’ when they reported on the study.

Investigation of DNA from the bones of ancient Europeans and from Europeans today is revealing surprising information about how their genetic make-up developed. The study mentioned above found a new ‘genetic marker’ was introduced as farming practices spread from the fertile crescent into Europe, from around 7000 years ago. This ‘marker’ section of DNA presumably entered the DNA of people in the fertlile crescent sometime prior to this, but from where is a mystery. This marker does not appear in the DNA of other ancient populations.

At an earlier period, the summary of the major study that has been done on European DNA describes what they think happened as “single, late and rapid dispersal” of non-African DNA to European and Asian populations 55,000 years ago. That the dispersal of this DNA is considered ‘rapid’ and ‘late’ indicates that this is a different process to the slow dispersal of hominid DNA happening prior to this.

It isn’t currently clear just where early modern humans evolved. The way that the scientists analyse all this is to look for ‘most recent common ancestor’ DNA of all humans, and of humans and other hominins such as Neanderthals and Denisovans. From this they can assess when populations diverged, such as the divergence between the European populations (which tend to have some Neanderthal DNA) and the Asian populations (which tend to have Denisovan DNA not Neanderthal DNA). The science looks very complex so it is not surprising conclusions are not very clear, but they are becoming clearer all the time.

Ancient DNA, that has been obtained from fossilised bones from various parts of the world, can also be related to the DNA of present-day humans. Up until relatively recently populations have tended to remain in the same area and intermixing of DNA has been limited. So the ancient DNA differences between population areas can still be identified in current populations.

European human bones prior to the last glacial maximum (20,000 BP) contain mitochondrial DNA lineage M, which is not often found in modern European DNA but is found in the DNA of Asians, Australasians and native North Americans. This suggests that at this period Europeans and populations in Eastern Asia were of similar origin.

The European population since then must have had far more inter-mixing of DNA from other sources than did the Asian populations, reducing the percentage that had the mitochondrial DNA lineage M. The study summary states that they have evidence for “a last glacial maximum genetic bottleneck”. This means that the DNA of modern Europeans is not what they would expect had the populations prior to 20,000 years ago continued to evolve and disperse. The DNA we see in modern Europeans seems to have come from a much more limited pool of ancestors, suggesting a population crash somewhere in the period around the last glacial maximum.

The pre-20,000 BP European DNA is referred to as European hunter-gatherer DNA. In the period from 20,000 to 13,000 years ago, bones from the whole area of Europe and the Middle East produce some European hunter-gatherer DNA, more in Northern Europeans than in people from the Middle East. As explanation of how the hunter-gatherer population of Europe changed, the study states that their data “...also provides surprising evidence of a major population turnover in Europe around 14,500 years ago during the Late Glacial, a period of climatic instability at the end of the Pleistocene.”. When scientific studies use a word such as ‘surprising’ it is clear that they think something is happening which is out of the ordinary and not the usual process of change in DNA through population inter-mixing. By their mention of ‘climatic instability’ one can guess that they have a few ideas as to what the cause might be, but like most scientists are unwilling to postulate things outside their field of expertise.

So we have here three mysteries:
- ’surprising’ DNA change in Europeans happening around 14,500 years ago.
- a genetic bottleneck, which must be a population crash.
- the appearance of a new genetic marker being carried from around 7000 years ago from the fertile crescent into European DNA, that appears to have arrived in the fertile crescent prior to this in a population from an unknown area of the world.

The first of these is relatively easy to explain. 14,500 years ago major land areas such as the North Sea and the continental shelf west of France and Ireland were being flooded. There will have been major migration of people from these areas into Europe.

A population crash is of course very easy to explain, provided one gives credence to the Bible and all the other stories worldwide about an extinction-level flood, followed by the traumas or ‘rain for 40 days and 40 mights’ that might refer to the start of the younger dryas period.

The third is rather harder to explain, as New Scientist acknowledge. It requires a population that moved into the fertile crescent area sometime during the few thousand years between 13,000BP and 7000 BP. A population that is not African, not Asian/Australasian, and not European hunter-gatherer.

We do have one intriguing story of an invasion of the Mediterranean, which has come down to us in the writings of Plato. If he was correct about the Atlantean civilisation, could they be the source of this surprising genetic marker?

Read the story for more.