Having all the same genes is not the same as having all the same variations of those genes. Do you have a cite for that claim about eye color? I’m not saying I know you’re wrong, but it sounds a little fishy to me. I’m not even sure we’ve identified all the genes that control eye color.
Let me clarify this…
There are certain mutations that occurred in populations outside (sub-Sahara) Africa. That is indisputable. To the extent that those mutations occur in African populations today, that is because of gene flow back to Africa from those non-African populations.
It should also be noted that the (theoretically determined) Identical Ancestor Point tells us that every living person today is descended from the same set of common ancestor who lived ~15k years ago. This means that there is no one living today who can trace all of his or her ancestry to sub-Sahara Africa further than 15k years ago. Some people may have only the tiniest fraction of their DNA from non-African ancestors, but that is still more than zero. [Link to Wikipedia article. PDF link to American Journal of Physical Anthropology article.]
Consider my ignorance fought.
I need some clarification though.
Start with the population of sub-Saharan homo sapiens from which we are all descended. Did the alleles associated with blue eyes arise in that population? Because my understanding is that of the gene pool that remains in sub-Saharan Africa, without mixing in genetic traits from younger, ex-African populations, light color eyes simply don’t appear. (I make an exception, of course, for albinism, but that is a complete lack of melanin, as opposed to a moderation of it.)
If the alleles exist in the original sub-Saharan gene pool, then inevitably, wouldn’t you see individuals who inherited the double recessives necessary for blue eyes? Yet - and I don’t mean this facetiously - I have never seen a picture of a person of direct sub-Saharan African ancestry with light colored eyes unless they also had some manner of European ancestry as well.
Or, bluntly, where are the black Africans with blue eyes?
Spell it out for me, 'cause I want to understand.
I can’t think of anyone I know here with light eyes, though I’m sure some of the people from North African/Middle Eastern stock must have them sometimes.
I’d venture most African-Americans have some white mixed in. African American visitors here are often honestly mistaken for white, because they look that different (and Cameroon is a very diverse country, so it’s not just because they look different than Cameroonians). I myself have been known to think “hey, theres a white guy” only to discover on closer inspection the man in question is black. And I think the main reason why African Americans (many of whom probably have ancestry here) is because most African Americans have some (or even many) white ancestors.
Maybe it’s astonishing to you, but it’s not to me. If you were to pull together a random sample of 100 African Americans, I’d hardly find it astonishing if 10 of them had “light” eyes, with hazel and grayish-green eyes predominating.
Of course, what looks “dark” to a white person may look “light” to a black one. So maybe color subjectivity leads you think differently than I do. Even accounting for that, though, I think “rare” is an overstatement. Just off the top of my head I can think of several light-eyed black folks, including both celebrities and run of the mill folk.
This is an interesting point, and one that has often occurred to me as well. Take someone like Harold Ford Jr, and most White Americans would call him Black. Send him over to Africa, and it wouldn’t surprise me if people there considered him White. It would seem that we notice most in others what we see that is different from ourselves, not so much what is similar.
I think if it wasn’t for the fact that Ford was well known (and known to be a black politician), most whites would probably see him as a white man. When my father was younger he looked a lot like Ford does, and he frequently was assumed to be white by other whites. (He knows this because they would share racist jokes with him and say other disparaging things about black people.)
I agree with this. Also, labels have power over our perceptions too.
Anecdote time: In middle school, my science teacher had the class stare at the person sitting next to us for 30 seconds and then write down a physical description of them. Then we were told to swap papers and read how we had been described. The guy sitting to me, a white guy, must have not been paying attention very well. Or he couldn’t tell his colors apart. Or something. He looked at my eyes and called them black. He looked at my hair and called them black. Now hair is one of those weird things that can look dark in certain light, so I gave him a pass for that. But my eyes? Not black at all.
Often I think when some folks think of black people, they just assume everything about them is literally black, despite evidence to the contrary. Just like when people think of twins, they automatically assume they won’t be able to tell them apart. Don’t matter if the twins look completely different from one another. People will still find a way to get them confused.
Yeah, Harold Ford might not have been the best example, especially when he keeps his hair clipped short-- he looks pretty darn White. But I think my point is still valid, you just need to find the right person.
monstro
She actually posted a link to a picture of herself* in a thread some time ago, and I agree.
*IIRC, it was a picture of her and several of the people she worked with.
I think my disagreement with Blake stems from my use of “light”. I’m equating “light” with “not dark brown”. I don’t know any black people with blue eyes, but I’ve known a lot with definitely “not dark brown” eyes. Sorry for the confusion.
Anyone ever seen that movie the “Human Stain?”
I can’t believe I didn’t think of him first, but Wentworth Miller , from “Prison Break” considers himself black , with a black father and white mother.
He and his father, like I’m pretty sure, most of us black folks in the US, are mutts.
I’m white and I think that I show evidence of being a mutt too.
My maternal grandfather’s hair was auburn but very kinky – not curly.
My mother had just a little bit of auburn in her hair and right in front of her ears, she had a little bit of kinky hair.
My hair is mostly dark with a tendency to curl and wave. But right in front of my ears it is kinky just like mother’s and granddaddy’s.
I don’t even see hair this kinky on Afro Americans these days, but I used to. Does the gene for this kind of hair come only from Black-skinned people originally? May I claim to be bi-racial?
I don’t see the logical connection between “Can’t trace ancestry back more than 15K” to “must have non-zero fraction of non-African DNA”, unless that IAP ancestor was necessarily not African. Please enlighten me.
Black people aren’t the only ones with kinky hair. Pacific Islanders have this hair type. I’ve also met Middle Easterners (particularly Egyptians) who have especially curly hair.
At the time of the IAP (sometime around 15k years ago), all living humans were either the ancestors of everyone alive today or no one alive today. Let’s call the first group A. Unless everyone in group A was living in sub-Sahara Africa at the time, then everyone alive today (including people in Africa) have non-African ancestors from that time period. The likelihood that all members of group A were African is extremely small.
If we go back farther, say to around 60k years ago, then all of our ancestors were probably still living in Africa. But not by 15k years ago. Some non-African genes (mutations that occurred in non-African populations) will have gotten back into African populations between then and now. We can’t know exactly how much, but it’s greater than zero. Note that we don’t all share the same percentage of DNA from everyone in group A-- some of us have more from certain subgroups and less from others, while some of us have a different mixture from the various subgroups.
This is the bit I don’t get - why exclude the possibility that some African person today has only African ancestors? I don’t see what in the scenario precludes it.
I’m probably just being dense, but I still don’t get it.
Because everyone in group A is an ancestor of everyone alive today. It’s not that we share some ancestors for that time, we share all of our ancestors.
You and I, and everyone else alive today, have the exact same set of ancestors at the IAP. We don’t get the same % of our genes from the same people, but we all get some of our genes from every single person in group A.
If you look at the distribution of humans at 15k years ago, we were pretty much everywhere (except maybe the Americas). But we had been living in Europe and Asia since about 35 -40k years ago, and in Australia from maybe 50k years ago. It would be extremely odd if all the people in group A lived only in Africa at that time.
If I’m not explaining it well enough, read the PDF file I linked to earlier. It’s not too technical.
That’s made it perfectly clear - I get it now, thanks.
Even though I wrote “for that time” instead of “from that time”? :smack: