WARNING: This post is full of speculations that I am recording for my own sake but are highly likely to be wrong!
Hey, did you know that this isn’t actually Haak et al’s full DNA graph? The actual full dataset looks like this:
Isn’t it beautiful?
You’re going to have to click for the full size–sorry I couldn’t fit it all into one screen cap. I’m also sorry that the resolution is poor, and therefore you can’t read the labels (though you should be able to figure out which is which if you just compare with the smaller graphic at the top of the screen. (Supposedly there’s a higher resolution version of this out there, but I couldn’t find it.)
Why the reliance on a greatly cropped image? Just the obvious: the big one is unwieldy, and most of the data people are interested in is at the top.
But the data at the bottom is interesting, too.
On the lefthand side of the graph, we have a measure of granularity–how much fine detail we are getting with our genetic data. The bottom row, therefore, shows us the largest genetic splits between groups–presumably, the oldest splits.
From left to right, we have selections of different ethnic groups’ DNA. Old European skeletons constitute the first group; the mostly pink with some brown section is Native North/South American; the blue and green section is African; the big wide orange section is mostly European and Middle Eastern; then we have some kind of random groups like the Inuit (gold), Onge (pink, Indian Ocean), and Australian Aborigines; the heavily green areas are India; the mixed-up area splitting the green is Eurasian steppe; the yellow area is East Asian; and the final section is Siberian.
Level One: Sub-Saharan Africa (SSA) vs. Non-Sub-Saharan Africa
The bottom row shows us, presumably, the oldest split, between the orange and the blue. All of these light blue groups, from the Ju Hoan (Bushmen/San) to the Yoruba (Nigeria,) Somalis to Hadza (Tanzania,) African Americans to Shua (Khoe speakers of Namibia/Botswana,) are from Africa–sub-Saharan Africa, I’d wager (though I’m not sure whether Ethiopia and Somalia are considered “sub-Saharan.”)
All of the other groups–including the sampled north-African groups like Saharawari (from Western Sahara,) Tunisians, Algerians, Mozabites (Algeria,) and Egyptians–show up in orange.
(Note: Light green and orange are completely arbitrary color choices used to represent the DNA in these graphs; there is nothing inherently “orange” or “green” or any other color about DNA.)
I would not actually have predicted this–other studies I have read predicted that the split between the Bushmen, Pygmies, and other groups in Africa went back further in Africa than the split between Africans and non-Africans, but perhaps the Sahara has been the most significant barrier in human history.
Interestingly, the split is not absolute–there are Sub-Saharan groups with non-SSA admixture, and non-SSA groups with SSA admixture. In fact, most of the SSA groups sampled appear to have some non-SSA admixture, which probably has something to do with back-migration over the centuries; predictably, this is highest in places like Somalia and Ethiopia, fairly high along the east coast of Africa (which has historically been linked via monsoon trade routes to other, non-African countries;) and in African Americans (whose admixture is much more recent.) (Likewise, the admixture found in some of the hunter-gatherer peoples of southern Africa could be relatively recent.)
The Non-SSA groups with the most SSA admixture, are north African groups like the aforementioned Algerians and Tunisians; Middle Eastern groups like the Druze, Syrians, Bedouins, Jordanians, etc.; “Mediterranean” groups like the Sicilians and Maltese; various Jewish groups that live in these areas; and a tiny bit that shows up in the people of the Andaman Islands, Australia, and PNG.
(Oh, and in various old European skeletons.)
Level Two: “Western” vs. “Eastern”
Moving on to level two, we have the next big split, between “Easterners” (mostly Asians) and “Westerners” (mostly Europeans and Middle-Easterners.)
Natives of North/South America, Inuits, Andaman Islanders, Australian Aborigines, Papuans, the Kharia (an Indian tribe that has historically spoken a non-Indo-European language,) some central or northern Asian steppe peoples like the Evens (Siberians,) and of course everyone from the Kusunda (Nepal) through China and Japan and up through, well, more Siberians like the Yakuts, all show up as mostly yellow.
Everyone from Europe, the Middle East, the Caucuses, and all of the sampled Indian populations except the Kharia have orange.
A bunch of little groups from the middle of Eurasia show up as about half-and-half.
Interestingly, some of the older European hunter-gatherer skeletons have small quantities of “Eastern” DNA; this may not represent admixture so much as common ancestry. It also shows up, predictably, in Turkey and the Caucuses; in Russia/Finns; tiny quantities in places like the Ukraine; and quite significantly in India.
Significant “Western” admixture shows up in various Natives North/South Americans (probably due to recent admixture,) the Andaman Islands, Aborigines, PNG, (this may represent something to do with a common ancestor rather than admixture, per se,) and Siberia.
Level Three: Native North/South Americans vs. “Easterners”
At this point, the “light pink” shows up in all of the sampled indigenous tribes of North and South America. A fair amount of it also shows up in the Inuit, and a small quantity in various Siberian tribes. A tiny quantity also show up in some of the older European skeletons (I suspect this is due to older skeletons being more similar to the common ancestors before the splits than trans-Atlantic contact in the stone age, but it could also be due to a small Siberian component having made its way into Europe.)
Even at this level, there is a big difference evident between the groups from Central and South America (almost pure pink) and those from northern North America, (significant chunk of orange.) Some (or all) of that may be due to recent admixture due to adoption of and intermarrying with whites, but some could also be due to the ancestors of the Chipewyans etc. having started out with more, due to sharing ancestors from a more recent migration across the Bering Strait. I’m speculating, of course.
Level Four: Intra-African splits
I don’t know my African ethnic groups like I ought to, but basically we have the Bushmen (aka San,) and I think some Khoe / Khoi peoples in green, with a fair amount of green also showing up in the Pygmies and other hunter-gatherers like the Hadza, plus little bits showing up in groups like the Sandawe and South African Bantus.
Level Five: Australian Aborigines, PNG, and Andamanese split off.
Some of this DNA is shared with folks in India; a tiny bit shows up in central Asia and even east Asia.
Level Six: Red shows up.
This reddish DNA is found in all “Siberian” peoples, people who might have moved recently through Siberia, and people who might be related to or had contact with them. It’s found throughout East Asia, eg, Japan and China, but only found in high quantities among the Inuit and various Siberian groups. At this resolution, oddly, no one–except almost the Itelmen and Koryak–is pure reddish, but at higher resolutions the Nganasan are, while the Itelmen and Koryak aren’t.
Level Seven: The “Indos” of the Indo-Europeans show up
Although no pure light green people have yet been found, their DNA shows up everywhere the Indo-Europeans (aka Yamnaya) went, with their highest concentration in India. Perhaps the light green people got their start in India, and later a group of them merged with the dark blue people to become the Yamnaya, a group of whom then migrated back into India, leaving India with a particularly high % of light green DNA even before the dark blue shows up.
Interestingly, some of this light green also show up in the Andamanese.
Level Eight: The “Europeans” of the Indo-Europeans show up
The dark blue color originates, in the left-hand side of the graph, with a several-thousand years old population of European hunter-gatherers which, as you can see in the slightly younger populations on the far left, nearly got wiped out by a nearly pure orange population of farmers that migrated into Europe from the Middle East. This dark blue population managed to survive out on the Eurasian Steppe, which wasn’t so suited to farming, where it merged with the light-green people. They became the Yamnaya aka the Indo-Europeans. They then spread back into Europe, the Middle East, India, central Asia, and Siberia. (The dark blue in modern Native American populations is probably due to recent admixture.)
Level Nine: The Hadza
The Hadza (a hunter-gatherer people of Tanzania) now show up as bright pink. No one else has a lot of bright pink, but the Pygmies (Mbutu and Biaka,) as well as a variety of other eastern-African groups located near them, like the Luo, Masai, and the Somalis have small amounts.
Level Ten: The Onge (Andamanese)
Not much happens here, but the Onge (from the Andaman Islands) turn peach and stay that way. It looks like a small amount of peach DNA may also be found across part of India (southern India, I’m assuming.)
Level Eleven: Chipewyans (North America)
The Chipewyans turn brown; brown is also found in small quantities in Central America, in moderate quantities in eastern North America, and in the Eskimo/Inuit.
Level Twelve: Pygmies
The Biaka and Mbuti Pygmies differentiate from their neighbors. Tiny quantities of Pygmy DNA found in probably-nearby peoples.
Level Thirteen: Inuit/Eskimo
They become distinctly differentiated from other North American or Siberian tribes (olive green.), Their olive green shade is found in small quantities in some Siberian tribes, but interestingly, appears to be totally absent from other Native American tribes.
Level Fourteen: Horn of Africa
A dusty peach tone is used for groups in the Horn of Africa like the Somalis and Ethiopians, as well as nearby groups like the Dinka. Small amounts of dusty peach are are also found along the East Africa, North Africa, and the Middle East. Smaller amounts appear to be in a variety of other groups related to the Bushmen.
Level Fifteen: The light green turns teal
All of the light green in Europe turns teal, but much of the light green in India stays light green. (Teal also shows up in India.) I have no idea why, other than my aforementioned theory that India had more light green to start with.
Level Sixteen: Amazon Rainforest tribes
The Kuritiana and Suri show up in light olive; light olive is also found in small quantities in other parts of Central and South America, and tiny bits in parts of North America, and maybe tiny amounts in the Eskimo but I don’t see any in the Chukchi, Itelmen, etc.
Level Seventeen: Bedouins
The Bedouins turn light purple; this DNA is also found through out the Middle East, Turkey, North Africa, the Mediterranean (eg Sicily), Greece, Albania, Spain, Bulgaria, Ashkenazim, and a tiny bit In India.
Level Eighteen: Some Bushmen appear to split off from some other Bushmen.
I don’t know much about these groups.
Level Nineteen: Nothing interesting appears to happen.
Please remember that all of this is me speculating. I am definitely not an educated source on these matters, but I hope you’ve had as much fun as I’ve had peering at the DNA and thinking about how people might have moved around and mixed and split to make the colors.