A breakdown by social class of the amount of European ancestry would be appreciated, instead of just an overall picture of the "mestizo" population.  
In Mexico, everybody has an amount of Amerindian ancestry, except recent immigrants. Even in the upper classes who look the whitest. Same goes for Colombia. 
 
The lower the class you would expect the less balance between autosomal and chromosomal analysis.

There's indeed linguistic evidence that Celtic languages originated in Iberia, but it's not necessarily the case that its diffusion was carried by large numbers of people. Aren't paleolithic inhabitants of the British isles largely the same genetically as the later neolithic ones?

Wouldn't it make more sense to look at UVR values around the time when selection for skin colour took place: i.e. the neolithic?  
It would also be fitting to take into account the time when present indigenous people migrated to those areas. 
Because the skin colour distribution as it is pictured in the map does not really show actual pigmentation, as some readers have pointed out, not only in the Americas and Australia, but also in Europe.

the author of the second quoted passage notes that only two Mediterranean islands were inhabited before the Neolithic  
 
Can you please mention those two islands? (I guess Sardinia and Cyprus)

Why all the fuss about a blond Berber girl? Blondism is more common during childhood, and appears in all Caucasian populations. For Berbers are still predominantly Caucasian, of mixed Upper Paleolithic (hence the robustness and residual blondism) and Mediterranean origins. 
As a rule, North Africans who identify as Arab (as opposed to Berber) are more likely to have recent Negroid and Arab ancestry.

J. 
As a zionist, do you have a problem opening up admissions for Asian students in Israel in the same fashion you advocate for the USA?

You cannot belong to Europe and to the Ummah at the same time or can you?