White-Americans are a subset of African-Americans

[mmmkay]

According to sampled comparison study of nucleotide polymorphisms, European-americans it would seem, are a genetic subset of their African-american counterparts.

What is interesting about the study is that african-americans are primarily of west african descent, not east-african, which is traditionally registered as the hot bed of human genetic diversity.

Normally, determining a person’s complete genotype would involve
examination of some 3 million base pairs in his or her DNA to identify
single nucleotide polymorphisms (SNPs) – differences of a single base
pair. To completely genotype 100 people – the minumum number
considered useful for comparative studies – would cost upwards of $1.5 million and would not be feasible. However, portions of the genome are known to be inherited together as a unit, reducing the number of SNPs that have to be identified: a single “tagging” SNP implies the presence of other SNPs that always go with it. Taking advantage of this knowledge, BEST is able to identify the minimum number of tagging SNPs that can distinguish genetic variations in a population, dramatically reducing the genotyping “workload” with no loss of information.

This method is described in an article published on line before print
on August 4th on the Proceedings of the National Academy of Sciences. The article shows that minimal haplotype tagging yields a saving of almost 90% on average and reaches above 95% in longer stretches of the genome. In the same publication, BEST is used to identify tagging SNPs for 105 genes in 24 African-Americans and 23
European-Americans. Interestingly, 95% to 100% of the tagging
SNPs found in the European-Americans were a subset of those in
the African-American subjects for all 105 genes studied. This
findings are consistent with the current hypothesis that Europeans
are descended from a small subset of Africans who survived the
migration to Europe.

www.chip.org/board/read.cgi?bid=1&aid=43&p=2




Interesting. Discuss. Ofcourse I expect it will be in the predictable dodona fashion and repsonse, but thats why I like this board. ;D

[Power Cosmic]

mmmkay said:

According to sampled comparison study of nucleotide polymorphisms, European-americans it would seem, are a genetic subset of their African-american counterparts.

What is interesting about the study is that african-americans are primarily of west african descent, not east-african, which is traditionally registered as the hot bed of human genetic diversity.

Normally, determining a person’s complete genotype would involve
examination of some 3 million base pairs in his or her DNA to identify
single nucleotide polymorphisms (SNPs) – differences of a single base
pair. To completely genotype 100 people – the minumum number
considered useful for comparative studies – would cost upwards of $1.5 million and would not be feasible. However, portions of the genome are known to be inherited together as a unit, reducing the number of SNPs that have to be identified: a single “tagging” SNP implies the presence of other SNPs that always go with it. Taking advantage of this knowledge, BEST is able to identify the minimum number of tagging SNPs that can distinguish genetic variations in a population, dramatically reducing the genotyping “workload” with no loss of information.

This method is described in an article published on line before print
on August 4th on the Proceedings of the National Academy of Sciences. The article shows that minimal haplotype tagging yields a saving of almost 90% on average and reaches above 95% in longer stretches of the genome. In the same publication, BEST is used to identify tagging SNPs for 105 genes in 24 African-Americans and 23
European-Americans. Interestingly, 95% to 100% of the tagging
SNPs found in the European-Americans were a subset of those in
the African-American subjects for all 105 genes studied. This
findings are consistent with the current hypothesis that Europeans
are descended from a small subset of Africans who survived the
migration to Europe.

www.chip.org/board/read.cgi?bid=1&aid=43&p=2




Interesting. Discuss. Ofcourse I expect it will be in the predictable dodona fashion and repsonse, but thats why I like this board. ;D

Very interesting and good link. I have to read the entire study to get a better understanding. I agree that this type of post will make some posters here react sort of hostile, but they should shoot the people who made the study, not the person who posted it here.

[Polako]

In the same publication, BEST is used to identify tagging SNPs for 105 genes in 24 African-Americans and 23
European-Americans. Interestingly, 95% to 100% of the tagging
SNPs found in the European-Americans were a subset of those in
the African-American subjects for all 105 genes studied. This
findings are consistent with the current hypothesis that Europeans
are descended from a small subset of Africans who survived the
migration to Europe.

This quote refers to the European population as a whole, not just European Americans.

It's referring to a theory that Europe was populated by migrants from Africa, who then adapted to life in Europe and became white Europeans.

This event happened tens of thousands of years ago, well before America was discovered and before any African or European migration there.

The point is that Africa has been the place where most people think humans evolved. This doesn't make modern Caucasoid populations some kind of an African sub-set though.

[mmmkay]

This event happened tens of thousands of years ago, well before America was discovered and before any African or European migration there.

Completely understood, but the subject of the study was african-americans and european americans. American is merely a nationality.

The point is that Africa has been the place where most people think humans evolved. This doesn't make modern Caucasoid populations some kind of an African sub-set though.

They are exactly that, although, less direct. Correct me if I'm wrong, but It does'nt seem as if much genetic change (besides the obvious surface differences) has taken place, hence the near identicality of their necleotide polymorphisms to africans. Much of the variations apparently took place prior to the migrations, and their ancestors were the ones who carried a subset of those variations.

[Hairless]

It wouldn't bother me one bit to discover I have African admixture, recent or not I'm not in denial like a lot of "white" people here

[Polako]

mmmkay said:

Completely understood, but the subject of the study was african-americans and european americans. American is merely a nationality.

Someone could read your post and infer that white Americans somehow evolved from black Americans in historical times.

It should be made very clear that the passage you're quoting refers to human evolution that took place tens of thousands of years ago.

They are exactly that, although, less direct. Correct me if I'm wrong, but It does'nt seem as if much genetic change (besides the obvious surface differences) has taken place, hence the near identicality of their necleotide polymorphisms to africans. Much of the variations apparently took place prior to the migrations, and their ancestors were the ones who carried a subset of those variations.

There's been both "surface" and genetic change.

Caucasoids don't carry the same paternal and maternal markers as sub-Saharan Africans, and their autosomal DNA is different.

If someone looks black, then in terms of autosomal DNA they will be black...if they look mostly black, their autosomal DNA will also be mostly black.

Caucasoid DNA originated in Africa, but it's no longer African.

[mmmkay]

Caucasoid DNA originated in Africa, but it's no longer African.

I'm almost certain that modern day geneticists don't refer to the term "caucasoid" anymore, however I understand the context of your usage.

Nevertheless, as the study and numerous other similar show,
the vast majority of the genetic material present in "caucasoids" appears to be a near complete subset of that in africa.

Be careful not to let generalised physical differences fool you. Africans bear a resemblance to new guineans and austro-melanesians but they appear to be the furthest apart.

I hope this continues to be a stimulating, interesting discussion.

[Melnorme]

The fact that whites are a subset of blacks in America might be surprising, because you'd expect African-Americans to have gone through some kind of bottleneck and lost some genes.

[Polako]

mmmkay said:

Nevertheless, as the study and numerous other similar show,
the vast majority of the genetic material present in "caucasoids" appears to be a near complete subset of that in africa.

Be careful not to let generalised physical differences fool you. Africans bear a resemblance to new guineans and austro-melanesians but they appear to be the furthest apart.

Modern genetecists refer to Caucasoids as West Eurasians. That's a case of semantics and political correctness.

I'm not sure what Australasians have to do with this?

Like West Eurasians and sub-Saharan Africans, Australasians have their own particular physical look and genetic profile. Because they inhabit a tropical climate they superficially resemble sub-Saharan Africans.

But my point is that it's very easy to tell apart West Eurasians from sub-Saharan Africans, both due to physical appearance and genetic profile...and that includes Y-chromosomes, mtDNA and autosomal DNA.

[Polako]

melnorme said:

The fact that whites are a subset of blacks in America might be surprising, because you'd expect African-Americans to have gone through some kind of bottleneck and lost some genes.

You seem to have no idea what you're talking about.

[mhagneto]

mmmkay said:

Caucasoid DNA originated in Africa, but it's no longer African.

I'm almost certain that modern day geneticists don't refer to the term "caucasoid" anymore, however I understand the context of your usage.

Nevertheless, as the study and numerous other similar show,
the vast majority of the genetic material present in "caucasoids" appears to be a near complete subset of that in africa.

Be careful not to let generalised physical differences fool you. Africans bear a resemblance to new guineans and austro-melanesians but they appear to be the furthest apart.

I hope this continues to be a stimulating, interesting discussion.

Not just Caucasians, but all non-Africans comprise this subset. It's fun to speculate about what went on in Africa before anyone left it.

One interesting point: it appears that, before the LGM, populations were astonishingly miniscule. According to some stuff I've read, in, say, 40,000 ky there were fewer than 10,000 individual members of mhs in the whole world.

[Melnorme]

polako said:

You seem to have no idea what you're talking about.

Well, yeah, I said 'might'. Besides, this isn't essential to your point because I was commenting specifically about the 'American' aspect of this, not the whole 'are whites = Africans' debate.
African-Americans are a selected subset of Africans and can't be used to prove anything in that regard, anyway.

[mhagneto]

melnorme said:

polako said:

You seem to have no idea what you're talking about.

Well, yeah, I said 'might'. Besides, this isn't essential to your point because I was commenting specifically about the 'American' aspect of this, not the whole 'are whites = Africans' debate.
African-Americans are a selected subset of Africans and can't be used to prove anything in that regard, anyway.

Wouldn't black Ams--derived from W Africans mostly-- still have some traces of ancient genetic material not found in those people who descend from "non-Africans"? I mean, the point made by mmkay to start this thread is nothing new--- merely a reconfirmation of something that's been known for a long time.

[asdf]

"African-Americans" are mulatos.

[Batrus]

Are african americans good for these kind of tests?

I'm mean, aren't they mixed with european americans?