What racial/social/ethnic/whatever distinct “group” of humans is the most genetically divergent from the mainstream of humanity?
The Bushmen of southern Africa, aka San, have some of the most divergent genetic markers. I believe as a group they are the earliest identified lineage to have split from other populations of humans.
Can you tell us more about them?
I would have guess the pygmies, are these the same people?
Jim
Here’s more on Bushman genetics.
It should be emphasized that just because the Bushmen possess some of the earliest known genetic markers, this does not mean they necessarily have a physical resemblance to early human populations. While they may preserve some early physical characteristics, they probably have others that originated more recently, and it would be difficult to tell which was which.
No. Although they are also a short-statured group (although taller than most Pygmies) and also until recently lived by hunting and gathering, they bear little other resemblance to Pygmies. I believe, however, that Pygmies are also a very old group.
Of human lineages that left Africa, the oldest surviving is I believe to be found among the “Australoid” groups, i.e. Australian aborigines, Papuans, and some relict groups of south Asia.
No. Pygmies (the Mbuti) are a different ethnic group.
Colibri: I tend think you’re answer is correct, and maybe this info is out of date, but Luigi Luca Cavalli-Sforza actuall has the Mbuti as the farthest “outliers” on the graph on pg89 of Genes, People, and Languages.
Thank You Colibri for the reply and the link.
Jim
Certainly both groups are very old. It may be that analysis of different markers would give somewhat different answers. I am not certain of the current consensus as to which group is older, if one exists, but my impression is that it is the Bushmen.
This article, which is much more technical, says:
The fact that both groups are very close to the root of modern human lineages, but do not resemble each other very closely physically except in stature, emphasizes that we can tell little about the appearance of early modern humans by looking at them.
In googling apparently "Bushman" is no longer PC.
I do think the concensus is that !Kung San are the oldest, but does the oldest have to be the most “genetically divergent from the mean”? Couldn’t it be that the oldest might be closest to the mean?
No. Which is the oldest is determined, essentially by definition, by which is most divergent from other lineages. (“Mean” is not really applicable here.)
This calculation is based theoretically on the concept of a molecular clock in genetics. Small mutations occur constantly in non-coding parts of the DNA. Since these parts do not code for genes, it is thought that these mutations have little or no effect, and hence are not subject to selection. For this reason they are known as “neutral” mutations. (Actually, some of these mutations may have some effects, but I’m not going to go into that here.) Since these mutations occur at a relatively constant rate, and are not weeded out by selection, the number of these mutations found in a lineage can be used to date the time of its separation from another lineage.
This method works best when lineages are completely separate. Since humans are all one species and can interbreed, some ancient genotypes can be found in more recent lineages. For example, some Bantu groups of southern Africa may have som ancient genotypes because they have interbred with Khoikhoi groups, related to the Bushmen.
Because the Bushmen and Pygmies have interbred relatively little with their neighbors, they represent distinctive lineages. Over time, each of these lineages has accumulated a large number of their own distinct mutations. Other lineages, which split off more recently, have had less time to accumulate their own distinct mutations and hence are more similar to each other than they are to Bushmen or Pygmies.
I think it wasn’t considered PC, and San was preferred, but now San is regarded as non-PC in some circles, and Bushman is regarded as preferable. Got that? 
“San” is a term used by the related KhoiKhoi (aka Hottentots, regarded as non-PC the last time I checked), and evidently derogatory. However, some San advocacy groups use the term themselves.
This came up in another thread recently, and the poster MrDibble, who himself is of partly KhoiKhoi ancestry, said in his opinion Bushman was preferable to San. I used Bushman instead of San in my reply based on that advice. I think he probably knows more about that issue than the US high school students in your link. But certainly there is a variety of opinions on the matter.
The whole thing is perhaps worse than the Eskimo/Inuit or Hispanic/Chicano/Latino business, so I’m not going to worry about it too much. As I mentioned in the thread where this came up before, I once worked on an exhibition on Pygmies where one of the reviewers regarded the term as pejorative, and insisted we substitute “short-statured hunter-gatherers.” I’m certainly not going to that here.
Yes, I think the key is that there isn’t a “mean” to begin with. If you’re measuring distances, it’s all relative to what you’re measuring against. And the OP asks about “the mainstream” of humanity, which also is meaningless unless we mean “the bulk” of humanity. The !Kung San are just as “mainstream” as any other group, except that we all represent more recently derived ethnic groups. Better to redefine the question in a form that can be objectively answered.
As Stephen Jay Gould was fond of pointing out, evolutionary “trees” are better thought of as “shrubs.” There is no main trunk, but instead a dense cluster of branches that come off at every level.
The Bushmen and the Pygmies represent branches that came off near the base of the shrub, while other populations branched off from one another higher up. The tips of the branches, however, which represent modern populations, are all exactly the same distance from the ground; we are all the same distance from ancestral humans. The key thing is that other populations are more like one another than any of them is like the Bushmen or Pygmies.
Except for the Bantu (per Cavilli Sforza) and a few other African groups, but that may be due to interbreeding, as I think you already mentioned.
Please note–Humans with Ginger-colored hair & pale or freckled complexion may have Neanderthal ancestry.
Is this divergent enought to qualify? Hybridization?
Do you have a reputable reference for this claim? The Wiki article makes that statement, but the reference it provides doesn’t in any way support it. In fact it never uses the word Neanderthal at all.
There may have been nearly one-way gene flow from Pygmies into the Bantu groups that moved into their areas. Pygmy females marry Bantu males, and their offspring become part of the Bantu group. Pygmy males are not considered to be suitable mates for Bantu females, so there is no corresponding gene flow from the Bantu into Pygmies. In the past, some anthropologists have asserted that some of the typical traits of sub-Saharan “Negroid” groups, such as wooly hair, are of Pygmy origin, but I don’t know if there is any actual genetic evidence of this. There may have been similar unidirectional gene flow from the KhoiKhoi/Bushmen into Bantu populations of southern Africa.
Recent genetic evidence strongly suggests that there was no interbreeding between Neanderthals and early modern humans; Homo sapiens and *H. neanderthalensis * seem to have functioned as good biological species where they overlapped. If there was any interbreeding, it has left no genetic trace in modern populations.
WOW!!! Just last night I watched the South Park episode on Gingers. I had never heard the term before, now here it is the very next day.
Good enough for me, it must be true.
Correct me if I’m wrong, but aren’t the Mbuti only one tribe of Short-Statured Hunter Gatherers (:)) among many?
This is mostly what I’ve heard recently - the idea that humans and neanderthals interbred is becoming less popular. What exactly is the evidence either way? (And, for that matter, was there ever any real reason to think they did, aside from the fact that there was some geographical overlap?)