Which Groups Have the most Neanderthal and Denisovan DNA?  

 

beautifulneanderthalDenisovan
Neanderthal and Denisovan contributions to different populations by chromosome (source)

Here are the numbers I’ve found so far for Neanderthal and Denisovan DNA in different populations:

 et al, in The Combined Landscape of Denisovan and Neanderthal Ancestry in Present-Day Humans, 2016, report:

Native Americans: 1.37%
Central Asia: 1.4%
East Asia: 1.39%
Oceana (Melanesians): 1.54%
South Asia: 1.19%
Europeans: 1.06%

(I have seen it claimed that the high Neanderthal percents for Oceanan populations (that is, Melanesians and their relatives,) could be a result of Denisovan DNA being incompletely distinguished from Neanderthal.)

Prufer et al, [pdf] 2017, report somewhat higher values:

East Asians: 2.3–2.6%
Europeans: 1.8–2.4%

While Lohse and Frantz estimate an even higher rate of between 3.4–7.3% for Europeans and East Asians. (They found 5.9% in their Chinese sample and 5.3% in their European.)

The Mixe and Karitiana people of Brazil have 0.2% Denisovan (source); other estimates for the amount of Denisovan DNA in Native populations are much lower–ie, 0.05%.

I found an older paper by Prufer et al with estimates for three Hispanic populations, but doesn’t clarify if they have Native American ancestry:

Population Individuals Neandertal ancestry (%)
Autosomes X
Europeans CEU–Euros from Utah 85 1.17±0.08 0.21±0.17
FIN–Finnish 93 1.20±0.07 0.19±0.14
GBR–British 89 1.15±0.08 0.20±0.15
IBS–Spain 14 1.07±0.06 0.23±0.18
TSI–Tuscan 98 1.11±0.07 0.25±0.20

East Asians CHB–Han Chinese Beijing 97 1.40±0.08 0.30±0.21
CHS–Han Chinese South 100 1.37±0.08 0.27±0.21
JPT–Japan, Tokyo 89 1.38±0.10 0.26±0.21

Americans CLM: Colombians from Medellin 60 1.14±0.12 0.22±0.16
MXL: Mexicans from LA 66 1.22±0.09 0.21±0.15
PUR: Puerto Ricans 55 1.05±0.12 0.20±0.15

Africans LWK: Luhya in Webuye, Kenya 97 0.08±0.02 0.04±0.07
ASW: African Americans South West US 61 0.34±0.22 0.07±0.11

Since the paper is older, all of its estimates are lower than current estimates, because we now have more Neanderthal DNA to compare against. However, you can still see the general trend.

The difference between “autosomes” and “X” highlighted here is that (IIRC) autosomes includes all chromosomes except the XY pair, and X is the X from that pair. They’re breaking them up this way because the X chromosome tends to have very little Neanderthal on it (and the Y even less), probably because Neanderthal DNA on these particular chromosomes was selected against.

Neanderthal DNA appears to have been selected for in areas that control hair and skin–people who had just left Africa were adapted to the African environment, and Neanderthal hair and skin traits helped them survive in colder, darker winters. We also see a lot of Neanderthal DNA influencing inflammation/immune response–these may have helped people fend off new diseases. But we see almost no Neanderthal (or Denisovan) DNA in areas of the genome that code for sperm, eggs, testes, ovaries, etc. These parts of people were probably already finely tuned to work together, didn’t need to change with the environment, and changing anything probably just made them less efficient–so Neanderthal (and Denisovan) DNA on the X and Y chromosomes has been purged from the Homo Sapiens gene pool.

North African Populations Carry Signature of Admixture with Neanderthals reports its data relative to the European average (which I believe is the CEU pop, 1.17%, so I’ll do the math for you to figure how much Neanderthal they have.)

Algeria 44.57% = 0.52% Neanderthal
Tunisia 100.16% = 1.172 N
Tunisia 138.13% = 1.6% N (This is an interesting population that has been highly endogamous and thus better reflects historical populations in the area.)
Egypt 58.45% = 0.68% N
Libya 56.36% = 0.66% N
Morroco North 69.17% = 0.81% N
Morocco South 17.90% = 0.21% N
Saharawi 50.90% = 0.6% N
Canary Island* 101.44% = 1.187% N
China Beijing 193.43% = 2.26 % N
China 195.41% = 2.29% N
Texas Indu Gupti 84.37% =0.987% N
Andalusia*118.66% = 1.39% N
Tuscan 94.90% = 1.11% N
Basque BASC 129.48% = 1.51% N
Galicia* GAL 115.86% = 1.36% N
Yoruba YRI  0.00% = 0% N
Luyha LWK  −14.89% = N

The authors note that they are not sure how the Luyha received a negative score–perhaps the presence of admixed DNA from yet another species is interfering with the results.

According to Wikipedia:

Denisovan DNA is most commonly found in Melanesians, Papulans, Aboriginal Australians and Aboriginal Filipinos, who all have similar amounts around 4-6%, indicating that they probably were all one group when their ancestors met the Denisovans. However, the similar-looking but historically quite isolated Onge people have no Denisovan–so they split off before the event.

In Papuans, Neanderthal DNA tends to be expressed in brain tissue, Denisovan in bones and other tissues.

Asians have a small amount of Denisovan DNA; Tibetans have a particular gene that lets them absorb oxygen effectively at high altitudes that they got from the Denisovans.

The Mende People of Sierra Leon may derive 13% of their DNA from an as-yet unknown hominin species (ancient DNA and bones do not preserve well in parts of Africa, so finding remains and identifying the species may be difficult.)

The Yoruba derive 8 or 9% of their DNA from the same hominin.

Masai have a small fraction of Neanderthal–since they are 30% non-African, probably about 0.35% of their genome–but you can read the paper yourself. 

Biaka Pygmies and Bushmen (San): 2% from an unknown archaic.

With more testing, better and more comprehensive numbers are sure to turn up.

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New Zealand: where prehistoric migrations and historic migrations meet

… There were, however, some societies, like those in the Pacific, which developed in extreme geographical isolation, since less than one percent of the Pacific is land. For hundreds of years, the Pacific sat apart from the major trade routes and so the cross-fertilization of naviational ideas was limited. One result of this was that the unique navigation methods that were developed in the Pacific remain distinct and different to this day. –Tristan Gooley, The Natural Navigator

The Pacific is also the last (major) region of Earth to be settled. We figured out how to survive on the polar sea ice thousands of years before we figured out long-distance ocean navigation. Humans didn’t arrive in New Zealand until sometime around 1250-1300 AD, (which means they got to Hawaii and Easter Island–one of the mot geographically isolated places in the world–before New Zealand.) Or to put it another way, less time passed between the Maori settling New Zealand and Columbus arriving Cuba than between Columbus and the American Revolution. (This is even more remarkable when you consider that humans arrived in Australia 40-50,000 years ago.)

I found one in English

The short version of all of this, as we’ve been discussing, is that the Melanesians (who, as their name indicates, have a lot of melanin,) spread out along the southern coast of Asia following the Out-of-Africa event, settling in the Andaman Islands, modern Indonesia, PNG, and eventually Australia.

After that, they basically stopped. The distances between their islands and the next islands were too great for Melanesian technology, and the islands they had were probably pretty nice compared to taking their chances out in the open waves just to hope they might make landfall on some tiny speck hundreds or thousands of miles away.

About 32,000 years later, a group of Taiwanese folks (probably also descended from Melanesians,) developed some better boats and navigational technologies and set out to discover the Pacific.

Micronesian "stick chart" for mapping ocean swells and currents (National Geographic)
Micronesian “stick chart” for mapping ocean swells and currents (National Geographic)

(Interestingly, they also went in the opposite direction, across the Indian ocean, and settled in Madagascar.) The Polynesians who eventually landed in New Zealand are among their descendants.

austronesian-expansion

Getting to Indonesia does not seem to have posed much of a problem for ancient man, since Homo Erectus got there even before h. Sapiens, a good 1.5 million years ago. Lower sea levels probably made this easier than it would be today, by linking up a lot of the islands to the mainland.

(I believe Indonesia is actually located on a sinking magmatic “cool spot” that is essentially drawing the whole region downward, leaving only the tips of its mountains above water; southern Africa is located over a rising magmatic warm spot, lifting the crust in that area.) But the movements of large chunks of crust across the mantle are beyond our temporal scope; we just want to know what Indonesia, PNG, and Australia looked like during the Ice Ages:

Indonesia and Australia during the Ice Age
Indonesia and Australia during the Ice Age

This still requires boats to cross, but it’s not too complicated a voyage. New Zealand, though, is right out. You’re not getting to New Zealand this way–the ocean currents are against you. I suspect it’s easier to get to NZ from the middle of the Pacific–as people actually did–than from Australia.

 

 

Cargo Cults

I find Cargo Cults rather fascinating.

Briefly, once upon a time, folks living on small isolated islands in the middle of the Pacific Ocean were minding their own business, tending their little gardens or hunting/gathering/fishing, when World War II invaded.

When the soldiers weren’t busy shooting each other in front of the natives’ huts, they were generally busy building airstrips so they could land their planes, building hospitals, supplying the troops, etc. Sometime the troops were re-supplied by air–and sometimes these bags of food happened to drop into the local villages, rather than the hungry troops.

Then WWII ended, and all of the newcomers left. Goodby went the planes and the hospitals and the bags of food from the sky. And the locals, confused, tried their darndest to coax the newcomers back. They built runways and wicker planes, carved radio headsets and rifles out of wood. They reenacted the steps the newcomers had taken to make the sky gods send bags of food, and prayed to their new god, “John Frum.”

It appears that no one had bothered to tell these guys what the hell was going on.

It is easy to look down one’s nose at an ignorant person. But it is hard to understand shit if no one will tell you what is going on.