The Spread of R1b

[ironroad41]

The current accepted model is that the R1b's migrated from the East to the West in several waves; the timing of which is argumentative. There are diffusion models, see M. Richards or Currat and Excoffier, that argue that under diffusion the older gene pool predominates as the population spreads..

If we look at colored pie charts of the distribution of R1b we see high saturation in the west moving to low percentages in the East. Given the above statements as being true - this distribution doesn't seem to make sense?? In fact its almost backward. The pie chart distributions, looked at by themselves, suggest origin in the west with a decreasing percentage as you move east.

I have been suggesting lately that the more recent out of africa scenarios 15K BP to present suggest possible migrations from northern africa in the 15K to 10K BP period and then again about 5 to 7K BP. From 15K to about 5K, apparently the Sahara was inhabitable with plenty of rivers, game and vegetation. Tunisia and Gilbraltar are the most likely departure points?

So my question/discussion point is why do see the distribution of R1b that we do and why is the largest concentrations of R1b populations the furthest from their "place of origin"???

[Deirwha]

R1b spread

1) Did not know this was the model. The model I learned is that R1b moved out of the compressed pocked of Northern Spain, So France after the last ice age and spread north, east and south. The model I learn suggested R1b's expansion reached into the Steppes maybe as far as Iran, certainly the Caucasus mountains.

2) In any case, there is are several plausible conventional explanations for the concentration of R1b in the West of Europe: a) the Scythians, Huns, Mongols, etc brought significant pressure from the East far as Germany and even at one point Gaul. The Moslem explosion brought pressure from the east through the Balkans and via the Moors as far as Northern Spain.

[ironroad41]

origins of R1b

I agree that your first scenario is plausible. Certainly, it appears that the Irish Clans (Scotti,Cruithni,Laiginn and Gael) all are derived from Iberia. The question is when did they get to Iberia and by which route?? Archaeological data cannot deny the proposition they arrived before the last Ice Age nor can they deny they came about 5K to 6K BP? There is no solid proof. So, anyone can put forward a "genetic" based argument and Archaeology can't disprove it. There are cave records depicting drawings in France and England that go back to the Aurignacian. The question is: what was the haplogroup of these people.

The Hun invasion and Moor invasions are both AD events, I believe. I do not believe they greatly changed the genetic makeup of western europe. Whether those invasions caused a "population compression" into a smaller area is a point of debate and I would be interested in others opinions?