I don’t know … for all the talk about the One Drop Rule, in my experience it doesn’t seem to apply unless there is some physical evidence, even if slight, of black ancestry. It can also be expressed in the reverse: I’ve never known a person of completely white appearance who has identified as black based on some trace genetic evidence.

Although in theory the One Drop Rule means that black identity continues forever, as a practical matter I believe that people with very low percentages of black ancestry, for example less than 1/32, do not generally identify as black.

The trend in New World countries is for mixing to take place and as this something which cannot reverse and only grows with time, we can more or less anticipate that future New World country citizens will be roughly admixtured in proportion to the percentage that the various groups make up in the ancestral population. That doesn’t mean that all sub-groups will necessarily meld with the general population as religious groups can maintain the biological separateness for many of the people that are born into them.

From an Australian perspective, I feel that the population of the Northern tropical parts and the Southern parts of Australia are quite likely to be different in their make-up. Northern Australia has not been that successful in attracting and retaining immigrants of European descent. Also after an initial period of traumatic decline, the Aboriginal population is growing quite fast in all parts of Australia but this is of more significance in Northern Australia because it makes up a much bigger proportion of the total. Northern Australia also quite a high percentage of people of Asian origin.

If their amount of non-Caucasoid admixture is very variable (say, from 0% to 20%), a minority (however small) of them may show some non-Caucasoid features despite 3% average.

the key is that there is going to be variance about this, and a non-symmetrical amount at that. it is possible that someone with 15% non-euro admixture would show some evidence, because the boer are mostly dutch and german (with some south french too), and so very fair and northern european in the null.

#28, you are probably correct. see my posts on cape coloureds. the boer admixture will be a reflection of those proportions.

What is the amount of the average non-Caucasoid admixture in Boers? Also, do some Boers show non-Caucasoid physical features? 3% (if it is true) seems too low to me to have an effect on physical features.

i agree. the argentine fractions are far too high to be explained by spanish sub-saharan ancestry.

And I never met someone with full Spaniard or Portuguese ancestry that show mixed features, like I saw betwen the Boers, for instance.

this does not surprise me. the latter probably have several multiples more average non-european ancestry (e.g., 0.5% vs. 3%?).

this is false. the 1000 genomes has a lot of spanish data. it seems clear that in fact spaniards have a particular excess of (a percent here and a percent there) of sub-saharan african ancestry. i’ve played with the data set myself, and this is pretty obvious when you compare to other european data. the main exception are the basques.

this isn’t an issue that’s really up for debate. unless you argue strong unrepresentativeness the data are as they say. you can play with them yourselves. you should get yourself genotyped.

What were the results for Australia? I’d think the policy for 100 years of taking any “aborigine” 75% or more European away, and putting them in white foster families, would have resulted in some Aboriginal ancestry.

Also, the early use of Australia as a penal colony meant that the gender balance was way off. Out of the 167,000 convicts brought in before 1868, only 25,000 were women. Some free settlers were migrating as well, of course, but they did not have a surfeit of women.

Of course, the Aboriginal population was never as high as the indigenous population in the Americas, so it may have been lost in the shuffle so to speak.

I’m not aware of any admixture studies of white Canadians, Australians, or New Zealanders. However, I wouldn’t be surprised in in some cases non-white admixture was closer to the Afrikaner levels than the white American levels – particularly for Australia, and French-Canadians (although I know the latter doesn’t count). Certainly the color lines were not tremendously high barriers in comparison to the U.S.