U5b1f1a in the Basque

[GailT]

Renfrew and Forster: "But she gets into difficulties with the Basques .... We prefer the alternative assumption that the Basque population, like much of that of Western Europe, is a Palaeolithic relic, supplemented by some later genetic input from the incoming first farmers."

I don't think it is widely known that approximately 12% of all Basque people descend from a single U5b1f1a maternal ancestor who may have lived around 1000 BC. This 12% estimate is based on my analysis of the HVR data from the 2012 Behar et al. Basque study, and the age estimate is based on 15 FMS samples (12 from GenBank and 3 from the U5 project) which have an average of 1.11 extra mutations.

If you exclude U5b1f1a, the Basque U5 mtDNA distribution is very similar to other southern European populations, so there is no evidence for a Paleolithic origin based on mtDNA. The high frequency of U5b1f1a suggests drift in a small population. I'm not up to date on analysis of Basque autosomal DNA but I wonder how much of the unqiueness might be the result of genetic drift in an isolated population?

And with all of the recent ancient mtDNA studies, there really no basis to continue to believe that much of Western Europe is a Palaeolithic relic.

[Jean M]

And with all of the recent ancient mtDNA studies, there really no basis to continue to believe that much of Western Europe is a Palaeolithic relic.

I know that. You know that. Most of us here know that. But it has been a slow process even for geneticists to let go of what seemed at one time a logical idea. The Basques as Palaeolithic relic was certainly an appealing idea for many archaeologists for decades. Paradigm change doesn't happen overnight. It would have been pointless for me to wait until everyone was convinced before I published. By then the world would have a dozen books saying the same thing.

[Humanist]

[A]pproximately 12% of all Basque people descend from a single U5b1f1a maternal ancestor...

Wow. I did not know that!

[parasar]

Wow. I did not know that!

Most lines just die out.
After all 270 million males descend from just three males ~4000bc! Yan et. al.

~6 kya (thousand years ago) (assuming a constant substitution rate of 1e-9/bp/year) indicates that ~40% of modern Chinese are patrilineal descendants of only three

[R.Rocca]

I don't think it is widely known that approximately 12% of all Basque people descend from a single U5b1f1a maternal ancestor who may have lived around 1000 BC. This 12% estimate is based on my analysis of the HVR data from the 2012 Behar et al. Basque study, and the age estimate is based on 15 FMS samples (12 from GenBank and 3 from the U5 project) which have an average of 1.11 extra mutations.

If you exclude U5b1f1a, the Basque U5 mtDNA distribution is very similar to other southern European populations, so there is no evidence for a Paleolithic origin based on mtDNA. The high frequency of U5b1f1a suggests drift in a small population. I'm not up to date on analysis of Basque autosomal DNA but I wonder how much of the unqiueness might be the result of genetic drift in an isolated population?

And with all of the recent ancient mtDNA studies, there really no basis to continue to believe that much of Western Europe is a Palaeolithic relic.

I'm not going to arguing for or against anything here, but I'll point out that most areas that have high frequencies of specific subclades have founder effects. However, on it's own, it does not prove or disprove an origin point. In fact, areas of high concentrations of a sublade are probably more likely to produce a founder here or there. Also, let's not forget that there was a human refugium in northern Iberia and it had to belong to a subclade.

[MitchellSince1893]

Most lines just die out.
After all 270 million males descend from just three males ~4000bc! Yan et. al.

Maybe Noah's three son's were Chinese instead of from Mesopotamia

[GailT]

Wow. I did not know that!

It's actually more than 12% in some regions. From Figure 1 of the Behar et al. 2012 paper, in Zone B (in green), Basque-speaking regions located in France (Lapurdi/Baztan, Lapurdi Nafarroa, Zuberoa) 16% of the 193 samples are U5b1f1a. In the Castillian speaking area, only 2.8% of the samples were U5b1f1a. In the nearby region of Asturia there was only a single U5b1f1a sample, 0.2% of the population.

[GailT]

I'm not going to arguing for or against anything here, but I'll point out that most areas that have high frequencies of specific subclades have founder effects. However, on it's own, it does not prove or disprove an origin point. In fact, areas of high concentrations of a sublade are probably more likely to produce a founder here or there. Also, let's not forget that there was a human refugium in northern Iberia and it had to belong to a subclade.

I agree, but the key point is that in the case of the Basques, it is a very recent founder effect that represents a large percentage of the population - nearly 1 in 6 French Basques share a common maternal ancestor who lived around 1000 BC. U5b1 is very ancient in Iberia, but there is not any unusual frequeny or diversity of U5b1 among the Basque - they are very similar to other regions in southern Europe after you exclude U5b1f1a. So it seems to be chance that the founder was U5b1f1a and not some other haplogroup. Another possibility might be that there was natural selection for U5b1f1a.

So I think the fact that it is a very recent founder effect implies a recent population expansion, and this makes an ancient origin seem less likely.

[maybe I should move this discussion to the mtDNA area?]

[tonisegovia]

Dear all,
Greetings to you all. New member here. I just joined anthrogenica.com following my genotyping as U5b1f1a after full mtDNA sequencing at FTDNA.
May I ask any of you for an update on the current knowledge about U5b1f1a? Was U5b1f1a the founder? " So it seems to be chance that the founder was U5b1f1a and not some other haplogroup. Another possibility might be that there was natural selection for U5b1f1a." Could you please elaborate on those 2 options?



Does it continue to be valid the notion that U5b1f1a lived around 1000BC?

[GailT]

Does it continue to be valid the notion that U5b1f1a lived around 1000BC?

There are 21 full sequence samples for U5b1f1a and the average number of extra mutations is 0.45, and the Soares spreadsheet gives an age estimate of about 2500 years, but there is uncertainty in the estimate of several hundred years or more. The "natural selection" idea is speculative, I don't know of any evidence to support it, and not sure if it is worth pursuing. I would guess this is a founder effect in isolated population.