It may not exactly overlap with geographic ancestry, but if self-reported race can be predicted by DNA tests, how can it not be reflective of real genetics
Predict is a relative term.
A south American native with Black skin color can have more DNA in common with a Japanese than two native Africans from different parts of Africa.
How so? It is a supervised learning problem: you have DNA markers as input features and self-reported race as the target class. If the model reaches >99% accuracy (*) I would say it performs pretty well.
(* The classes are skewed, but not extremely skewed. I don’t know if this accuracy has been corrected by class skew, but even if it hasn’t you wouldn’t get this accuracy unless the model didn’t work as intended).
A south American native with Black skin color can have more DNA in common with a Japanese than two native Africans from different parts of Africa.
Would this South American “native” self-identify as “black”?
How so? It is a supervised learning problem: you have DNA markers as input features and self-reported race as the target class. If the model reaches >99% accuracy (*) I would say it performs pretty well.
The point I wanted to make is that in the real world models in this area don’t have >99% accuracy.
Would this South American “native” self-identify as “black”?
That depends on the social environment. If they want to apply to an university that has a quota for Black students it wants to accept and their skin color is Black, there a good chance that they will put Black in the field that asks for the race.
A lot of people think it makes sense to speak of a Black race, a Caucasian race, and an Asian race as if two Black people would be as genetically similar as two Caucasians or as two Asians.
South American natives and Asian people are both descendants of the African tribe that left Africa ~100,000 years ago. Some South American natives have spent enough time near the equator so that they are also as Black as Africans.
I’m not sure that’s true if “nobody ever” is meant literally (and I’m pretty sure I’ve heard dark-skinned Indians referred to as black people a couple of times), but yadda yadda weak men yadda yadda, so good point.
Uhm, neither of those are talking about South American natives as if they were “negroes”. I’m pretty sure they’re talking about the Afro-descended people living there, since they also distinguish between them and the natives.
I’ll grant that some thought the Pacific Islanders were “negroes” though.
I’m not at all sure that first part is true, in a practical sense. Though going by the actual method of classifying individuals does bring in other problems.
I don’t know if we’re talking past each other or if I’ve catastrophically misunderstood your point—but what does the first link have to do with the distinction between SA natives and Africans in SA?
It talks about people who “despise the Brazilian people because of the manifest admixture of African blood in their make-up.” Now this is ambiguous—most people in Brazil have non-zero African ancestry, maybe even more than white US citizens have. But it looks to me like the quoted author is in fact classifying people by skin color alone. They simply assume that Italians and various others have “swarthiness” from the same source (falsely, according to the best info I can find without really caring).
They simply assume that Italians and various others have “swarthiness” from the same source (falsely, according to the best info I can find without really caring).
Mediterranean Europeans are typically noticeably darker than Northern ad Eastern Europeans. Eye and hair color also clearly have a North-South and West-East gradient.
Predict is a relative term.
A south American native with Black skin color can have more DNA in common with a Japanese than two native Africans from different parts of Africa.
How so? It is a supervised learning problem: you have DNA markers as input features and self-reported race as the target class. If the model reaches >99% accuracy (*) I would say it performs pretty well.
(* The classes are skewed, but not extremely skewed. I don’t know if this accuracy has been corrected by class skew, but even if it hasn’t you wouldn’t get this accuracy unless the model didn’t work as intended).
Would this South American “native” self-identify as “black”?
The point I wanted to make is that in the real world models in this area don’t have >99% accuracy.
That depends on the social environment. If they want to apply to an university that has a quota for Black students it wants to accept and their skin color is Black, there a good chance that they will put Black in the field that asks for the race.
The link many comments up suggests that we do in fact have >99% accuracy (when limited to major ethnic groups in the US).
Does anybody dispute this?
A lot of people think it makes sense to speak of a Black race, a Caucasian race, and an Asian race as if two Black people would be as genetically similar as two Caucasians or as two Asians.
South American natives and Asian people are both descendants of the African tribe that left Africa ~100,000 years ago. Some South American natives have spent enough time near the equator so that they are also as Black as Africans.
Nobody ever grouped black South Americans into the same race as black Africans. Where did you get that idea?
Racial classifications were never determined solely by skin color.
I’m not sure that’s true if “nobody ever” is meant literally (and I’m pretty sure I’ve heard dark-skinned Indians referred to as black people a couple of times), but yadda yadda weak men yadda yadda, so good point.
But people do group people from Ghana with the same race as people from Somalia even through they differ a lot in DNA.
They’re more related to each other than either is to a European.
I take it the word “nobody” means ‘Nobody in some particular club’?
Uhm, neither of those are talking about South American natives as if they were “negroes”. I’m pretty sure they’re talking about the Afro-descended people living there, since they also distinguish between them and the natives.
I’ll grant that some thought the Pacific Islanders were “negroes” though.
I’m not at all sure that first part is true, in a practical sense. Though going by the actual method of classifying individuals does bring in other problems.
I don’t know if we’re talking past each other or if I’ve catastrophically misunderstood your point—but what does the first link have to do with the distinction between SA natives and Africans in SA?
It talks about people who “despise the Brazilian people because of the manifest admixture of African blood in their make-up.” Now this is ambiguous—most people in Brazil have non-zero African ancestry, maybe even more than white US citizens have. But it looks to me like the quoted author is in fact classifying people by skin color alone. They simply assume that Italians and various others have “swarthiness” from the same source (falsely, according to the best info I can find without really caring).
Oh, I see your point now.
Okay, I agree that racial characteristics were sometimes determined by only skin color.
Mediterranean Europeans are typically noticeably darker than Northern ad Eastern Europeans. Eye and hair color also clearly have a North-South and West-East gradient.