Remnants at the fringes theory and the Ainu

I’ve been meaning to get around to this!

Here we have maps of the distribution of red hair and the distribution of blond hair. If we could overlay these maps, we’d see, especially in North Western Europe, a large overlap between the places where blond here is and red hair isn’t. It looks kind of like the blond-haired people started out somewhere around Sweeden and spread out in concentric circles from there, and as they spread, they began displacing an earlier, red-haired people who ended up surviving only on the far fringes of Britain. (The red splotch in the middle of Russia represents the Udmurt people, who could have been originally related to the ancestors of the folks on the coasts of Britain, but I suspect not.)

Luckily for me, we have historical records for this area, and we know that this is exactly what happened, what with the Germanic barbarians invading Gaul and Britain and Prussia and so on.

Anyway, so this is just an idea I’ve had kicking around in my head that when you see something like the red hair/blond hair pattern, the trait that’s in the easy to conquer, fertile, valuable areas is more recent, and the trait that’s in the fringier, more isolated places–sometimes widely separated–is the older one.

“Fringe” areas don’t have to be the edges of coasts. They can also be rainforests, mountain tops, deserts, icy tundra, etc.–just anywhere that’s far away or hard to conquer.

The Ainu

The Ainu are among the most famous Siberian peoples primarily because, once upon a time, Europeans mistook them for Caucasians, probably because the Ainu had beards and other East Asians tend not to. (I think East Asians generally can’t grow shaggy beards, but it’s hard to say because shaving one’s head is so common among men these days.)

Count the beards!

As it turns out, merely having a beard does not, in fact, make you Caucasian; the Ainu are most closely related to other groups from north / east Asia:

Graphs from “The history of human populations in the Japanese Archipelago inferred from genome-wide SNP data with a special reference to the Ainu and the Ryukyuan populations;” Dienekes, Lindsay, and Ahnenkult (via the Wayback Machine) have excellent posts on the paper.

It’s not surprising that the Ainu aren’t actually long lost Europeans, but it is odd that they appear to be most closely–though still distantly–related to the Ryukyuans (aka Okinawans,) and mroe distantly related to their immediate neighbors, the Japanese. The Ainu hail from Hokkaido, in the far north of Japan, (though they may have previously ranged further south:

)

while the Okinawans hail from Japan’s southern end. Here’s another look at their respective genetics:

So we’re left with the Ainu still being quite unusual.

For that matter, their beards actually are rather unusual for the area–while the neighboring Nivkh People have beards, most of the other nearby Siberian groups, like the Yukaghirs and Oroks, (not to mention their Japanese neighbors) don’t seem particularly beardy, even though facial fur seems like it’d be useful in cold places.

Ainu

Yukaghirs

To be clear, based on my past half hour’s worth of research, the Japanese (and other east-Asians) can grow beards, but their beards are generally thin and patchy due to the distribution of hair follicles. The fluffy, full beards of the Ainu appear to be rare among the Japanese and other east Asians.

I’ve yet to find a map I trust of the distribution of hairiness among humans, so we’re going with one I don’t entirely trust:

Why are Norwegians furry, but not Siberians?

Potential issues with this map: 1. Hindley and Damon gathered their estimates from the literature of their day, which means some of these numbers may be quite old; 2. Map is based on a measure of hairiness of people’s finger joints, not beards or overall body hair; 3. It looks like the numbers in the US are based on current populations rather than indigenous ones, which isn’t an issue so much as just something to be clear on; 4. the Wikipedia lists some of the numbers cited in the article, but not those for Melanesia/Indonesia/SE Asia, and the article itself is paywalled; 5. the article’s abstract notes that Solomon Islanders measured 58.8% hairy–purple–which seems in contrast to the very yellow area nearby.

At any rate, judging by the Wikipedia, lots of people rate the Ainu as “very hairy” and the Japanese as “not very hairy.”

Interestingly, the Australian Aborigines seem to have nice beards:

The article on Ainu genetics notes, “…Omoto conducted a pioneering study on the phylogenetic relationship of the Ainu population considering various degrees of admixture. When a 60% admixture with the Mainland Japanese was assumed for the modern Ainu population, the ancestral Ainu population was clustered with Sahulian (Papuan and Australian). This sort of simulations based on the real data is needed.”

Speculative… but interesting.

The Ainu belong to Y-haplogroup D-M55, a sub-clade of D-M174, which according to Wikipedia, is found “at high frequency among populations in Tibet, the Japanese archipelago, and the Andaman Islands, though curiously not in India. The Ainu of Japan are notable for possessing almost exclusively Haplogroup D-M174 chromosomes,…” (You remember our discussion of the Andaman Islanders the other day, right?)

It’d be interesting to know if the Ainu have any Denisovan admixture.

The Ainu language doesn’t seem to be related to any of the nearby languages, not even Nivkh (aside from loan words.) It’s hard to study the Ainu language, since very few people speak it anymore, but so far all of the proposed groupings sound very tentative.

The Ainu also have different teeth from their neighbors. “Sinodont” teeth are found in Japan, China, Siberia, and Native Americans. “Sundadont” teeth are found in the Ainu, Okinawans, ancient Japanese skeletons, Taiwanese aborigines, Filipinos, Indonesians, and folks from Indochina like the Thais and Laotians.

Here’s a helpful map:

(N = Negritos; A = Australians)

The word “Sundadont” refers to “Sundaland“, which is the part of Indonesia that was above water and connected to the mainland back during the last ice age. Getting to Indonesia was therefore potentially quite simple for ancient people, since they could just walk there; getting to Papua New Guinea and Australia was much more difficult, since deep water lay between them. WestHunter has an interesting post on the subject.

However, on the subject of Native American teeth, the Wikipedia notes:

“Rebecca Haydenblit of the Hominid Evolutionary Biology Research Group at Cambridge University did a study on the dentition of four pre-Columbian Mesoamerican populations and compared their data to “other Mongoloid populations”.^[3] She found that “Tlatilco“, “Cuicuilco“, “Monte Albán” and “Cholula” populations followed an overall “Sundadont” dental pattern “characteristic of Southeast Asia” rather than a “Sinodont” dental pattern “characteristic of Northeast Asia”.^[3]“

As we discussed previously, it looks like Melanesians may have been the first folks to reach the Americas, but were later conquered and largely wiped out by a wave of “East Asian”-like invaders.

Taken together, all of the evidence is still kind of scanty, but points to the possibility of a Melanesian-derived group that spread across south Asia, made it into Tibet and the Andaman Islands, walked into Indonesia, and then split up, with one branch heading up the coast to Taiwan, Okinawa, Japan, and perhaps across the Bering Strait and down to Brazil, while another group headed out to Australia.

Later, the ancestors of today’s east Asians moved into the area, largely displacing or wiping out the original population, except in the hardest places to reach, like Tibet, the Andaman Islands, Papua New Guinea, the Amazon Rainforest, and Hokkaido–the fringe.

Each group, of course, has gone its own way; the Ainu, for example, have mixed with the nearby Japanese and Siberian cultures, and adapted over time to their particular climate, resulting in their own, unique culture.

 

 

 

Species of Exit: The Sentinelese, the world’s most isolated people

North Sentinel Island

Map showing location of North Sentinel Island (red) relative to the rest of the Andaman Islands

Map showing the distance between the Andaman Islands (small islands south of Myanmar) and land.

The Sentinelese appear to have split off from the rest of humanity approximately 48,500 years ago, and aside from occasional contact with other members of the Andaman islands, have remained isolated ever since.

People have occasionally landed on or near Sentinel island, but the islanders have all resisted contact, generally by shooting arrows at anyone who gets too close. Even National Geographic hasn’t got any pictures of them–when they tried to make a documentary on the island, armed with gifts, they had to retreat after the director took an arrow in the thigh. The last guys whose boat accidentally drifted onto their beach got killed and buried in shallow graves on the beach.

North Sentinel Island is technically owned by India, but India has given up trying to make peaceful contact, and it would probably look bad to just bomb the place.

So what do we know about the Sentinelese?

Obviously not a whole lot, since most of what we know of them has been observed from a distance.

The whole island is about the size of Manhattan, and probably inhabited by 40-500 people. They’re generally characterized as Negritos, a term used for the shorter than average but taller than Pygmies, dark-skinned people of the Andaman Islands and certain groups in the Philippines, Thailand, and Malaysia. The term is only descriptive; different Negrito tribes may not be related to each other at all. (I promised I’d get around to the Negritos eventually.)

Aside from stuff that has randomly washed up on their island or was given to them by folks trying to make contact, they have only stone tools and, according to the Wikipedia, appear not to have fire.

But a little more research suggests that Wikipedia may just be wrong on this point; during the search for the lost Malaysian jetliner, smoke was observed rising from North Sentinele, which implies that the people there probably do have fire.

At any rate, we do know that they have bows and arrows, boats, and spears.

When National Geographic tried to make contact, they left a plastic toy car, coconuts, a live pig, a doll, and aluminum cookware on the beach before getting shot at. After they retreated, they observed the Sentinelese shoot and bury the pig (not eat it?) and, if the Wikipedia is accurate, shoot and bury the doll. They took the coconuts and pans; no word of the car’s fate.

In 1970, a group of Indian anthropologists that came near the island had a decidedly strange incident:

Quite a few discarded their weapons and gestured to us to throw the fish. The women came out of the shade to watch our antics… A few men came and picked up the fish. They appeared to be gratified, but there did not seem to be much softening to their hostile attitude… They all began shouting some incomprehensible words. We shouted back and gestured to indicate that we wanted to be friends. The tension did not ease. At this moment, a strange thing happened — a woman paired off with a warrior and sat on the sand in a passionate embrace. This act was being repeated by other women, each claiming a warrior for herself, a sort of community mating, as it were. Thus did the militant group diminish. This continued for quite some time and when the tempo of this frenzied dance of desire abated, the couples retired into the shade of the jungle. However, some warriors were still on guard. We got close to the shore and threw some more fish which were immediately retrieved by a few youngsters. It was well past noon and we headed back to the ship…

Virtually nothing is known about the Sentinelese language, though it is speculated that it is related to the Onge language of the Andaman islands. However, attempts at using the Onge as translators have failed, as the Onge themselves cannot understand a word of Sentinelese.

A British expedition in the 1880s that got a decent look at the island claimed that, of all the nearby groups, Sentinelese culture most closely resembled Onge culture, so it is still possible that the languages are related, albeit distantly.

Since much more is known about the Onge, I’m going to speak briefly about them:

Onge man collecting honey, Andaman Islands

The Onge are marked in blue on the map above; today they live chiefly on Little Andaman Island in the south, but in the past they ranged further north, closer to to the Sentinelese. Contact with the outside world has reduced their population from almost 700 people (1900) to about 100. (There may well have been >700 people before 1900, that’s just the first date I have numbers for.) Strangely, the Onge appear to be the world’s least fertile people, with 40% of couples suffering infertility. Wikipedia estimates their Net Reproductive Rate (similar to TFR, but only looks at daughters) at 0.91, which is below replacement, however, their population appears to have held steady for the past 30 years, so perhaps the problem is working itself out.

Why such infertility? The most obvious guesses (IMO) are some sort of environmental poison/effect; some sort of diseased-induced infertility, like gonorrheal scaring (please note that I have no idea if any of the Onge have ever had gonorrhea, but it is a common cause of infertility;) or a side effect of inbreeding/lack of genetic diversity following their extreme population collapse.

The article Malnutrition and high childhood mortality among the Onge tribe of the Andaman and Nicobar Islands suggests that the real cause of the low NRR is high childhood mortality due to malnutrition/insufficient food, probably due to loss of their traditional hunting/gathering grounds.

Genetically, the Onge appear to have been isolated for an extremely long time. They all share the same mitochondrial DNA, haplotype M32, which is not found anywhere outside of the Andaman Islands. (The larger umbrella-group M, to which all M-varieties belong, is one of the world’s most wide-spread lineages, emerging either shortly before the Out of Africa event, or shortly after it, but is most reliably concentrated in Asia, with several ancient lineages in India.)

The Onge language is related to the languages of some of the other tribes in the Andaman Islands, and speculated to be part of the greater Austronesian language family. (Considering that the whole Indo-European language family is about, what, 4-6,000 years old, I am a little skeptical of our ability to reconstruct too much about a language that may have diverged 40,000+ years ago.)

Onge Y-DNA belongs to Haplogroup D-M174, which emerged in Asia about 60,000 years ago and isn’t found outside of Asia. It is found today among Tibetans, the Ainu, and the Andaman Islanders, suggesting that these people are all (at least partially) descended from a common source that split off from other humans around 60,000 years ago, or just after the OoA (relatively speaking.) D-M174 is also found in small amounts in China and central/east Asia.

The Ainu, IIRC, also have a particular tooth shape that is commonly found in Melanesia, but not outside of it, and a small amount (about 15%, I think,) of Siberian DNA. And, of course, we now have evidence of Melanesian DNA showing up in the Amazon rainforest, not to mention the curious concentration of archaic Denisovan admixture in Melanesians, despite the only Denisovan remains we’ve found so far coming from Russia. However, it appears that there is no Denisovan DNA in the Andaman Islanders, so maybe they split off before the Denisovan admixture advent.

The sum of the evidence suggests a single band of people, perhaps most closely resembling the Negritos, spread 60,000 years ago along the coast of southern Asia and spread far into the interior, reaching at least as far as Tibet, the Andaman Islands, and northern Japan, and possibly even crossing the Bering Strait and down to the tip of South America. (Since Melanesians do not appear to have ever spread to Polynesia, I suspect they did not boat straight across the Pacific, but maybe we just haven’t yet found Melanesian remains in Polynesia.)

Over the ensuing millenia, later population waves, like the Polynesians and the common ancestors of east Asians like the Han and the Japanese, migrated into the area, leaving only a few isolated remnants of Haplogroup D-M174 in far-flung, difficult to reach places like the Andaman islands, the Himalayan Plateau, and the coldest parts of Japan. Likewise, Melanesian DNA in the New World seems to have best survived in one of its harshest, most difficult to penetrate habitats: the rain forest.

This all gets back to my theory of genetic survival at the fringes, (discussed here,) which I hope to devote a full post to soon. The history of the world is the group with better tech conquering the group with worse tech, and then getting conquered in turn by a group with even better tech.

The island of Taiwan illustrates this well; the most recent immigration wave happened in 1949, when the ROC lost their war with the PRC and evacuated 2 million of their people to Taiwan, a nation of 6 million at the time. Taiwan had previously (temporarily) been conquered by the Japanese, and before that, by other Chinese people, who began arriving around 1300. They’ve been gradually defeating/replacing the aboriginal Taiwanese, who are now a very small population, and the aboriginal Taiwanese themselves have legends about having wiped out a negrito-like people who predated their arrival, but I consider such legends only potentially true. Each group got conquered by the next group with better tech.

A couple more pictures of Andaman Islanders:

Onge mother and child, Wikipedia

 

Andamanese Couple, Wikipedia

Anyway, back to the Sentinelese.

The available evidence suggests that they split off from the rest of the human population ages upon ages ago, and have been effectively isolated from everyone but their immediate neighbors ever since. Though technically their island is considered part of India, as a practical matter, they govern themselves. They have managed to retain their independent status for so long by living on a tiny, hard-to-reach island and enforcing a strict immigration policy of killing anyone who shows up on their beach.

Given that the Sentinelese would probably all die of the common cold if they ever did let foreigners onto their island, their policy is not unreasonable. You wouldn’t want to let some plague-bearing foreigner kill you with their germs, either. Unfortunately, the disease situation is unlikely to reverse itself; their population is just too small to withstand contact with the outside world. Too-long isolation in such a tiny place has cut them off from all the technological progress of the past 40,000 to 60,000 years, and their population is too small to develop much tech internally. To be fair, their strategy has worked so far. But now they’re stuck, maintaining their tiny island against the odds until someone decides to show up with guns and do some logging, fishing, or whatever they feel like, at which point there’s a good chance they’ll be wiped out.

Long term, total isolation is a policy with very low survival odds.

After some thought, the best option I can think of for the Sentinelese, other than continuing as they are and hoping for the best (after all, the rest of the world could destroy itself in a nuclear holocaust and leave them behind to continue doing their thing for the next 40,000 years,) is to expand their numbers and send excess people to the other Andaman Islands. Sure, most of those people would probably get colds and die, and if not the colds, alcohol’s a likely culprit, but as long as they keep exporting people, eventually some of them will survive, and create a breeding population/intermix with the other Andamanese until they have the numbers/immunity to interact with the outside world.

So Why do Native Americans have so much Neanderthal DNA?

Warning: highly speculative post ahead.

As I mentioned the other day:

Worldwide distribution of B006, (from Yotova et al. “An X-Linked Haplotype of Neandertal Origin Is Present Among All Non-African Populations,” Mol. Biol. Evol. 28 (7), 2011).

SNP PCA from Skoglund & Jakobsson’s “Archaic Human Ancestry in East Asia” (2011)

(Please note that Africans do not have chimpanzee admixture, despite the labeling on the graph–no human group has chimp admixture, because chimps and humans have different #s of chromosomes, so even if you could get a successful cross, the resulting child would be infertile, like a mule. I assume the point of the chimp node is just to represent that which has neither Neanderthal nor Denisovan admixture, though of course there is the possibility of some other form of archaic hominin admixture in Africans.)

So, Native Americans appear to have a ton of Neanderthal DNA. (Relatively speaking.)

Possibilities:

1. It’s all measurement error/convergent evolution/something else other than archaic admixture.

As much as I hate to say it, I still consider this very likely. There is just a ton of stuff that we don’t about the Americas–like how and when people first got here. I’m sticking here with what I think are the most scientifically-supported theories, but a lot of this is still quite disputed. In particular, all of this genetic admixture business is still kind of speculative, and when people start talking about finding admixture in the admixture, either life is totally awesome, or we’re trying too hard.

2. Survival at the Fringes theory

A lot of people seem to look at this data and respond with something like, “But Neanderthals are from Europe, not America!” But this is not a big issue; the Indians are descended from people who passed through Neanderthal-inhabited regions (the Middle East), just like everyone else with Neanderthal DNA. The migration to the Americas took place long after they acquired Neanderthal admixture.

But this doesn’t explain why they have so much of it.

My “concentration on the edge” theory states that when one population is displaced by another population, you end up with a “fringe” of the original population’s traits. Sometimes this fringe results in isolated groups, as the invading population completely surrounds or cuts off a remnant population from their former range.

The Ainu, for example, resemble certain other Oceanin groups, but not their neighbors, the Japanese. I’m speculating here, so don’t take my word for it.

But I have a much better case with the distribution of red hair:

(So far I have found nothing explaining that dot over in Russia.)

Red hair is highly associated with the so-called Celtic fringe. It looks like it’s highly concentrated in Wales, Scotland, and parts of Ireland, but since I know a little history, and I know these aren’t areas of concentration, but just the areas that managed to escape being displaced by Anglo-Saxon invaders, just by virtue of being further away from the south-east coast of Britain.

One can imagine that the isolated dot in the middle of Russia might, at one time, have been connected with the other red-haired regions before other peoples invaded the lands between them and cut them off.

Compare to the map of blond hair:

Blond hair looks like it has been spreading steadily outward from a central source.

So what does this have to do with Neanderthal admixture in Native Americans?

It means that I think the Native Americans may have closer to original levels of Neanderthal admixture, while people in Europe and Asia have lower admixture because they mixed with later waves of people who came from Africa and had no Neanderthal admixture.

3. The Bering Strait selected for Neanderthal admixture

Alternatively, the harsh conditions of life in the Bering Strait–where some scientists think the ancestors of today’s Indians hung out (or “paused”) for thousands of years before the ice sheets opened up to let them through–may have selected for winter adaptations that came from ice-age Neanderthals. I have speculated previously that Type-2 Diabetes may actually be a winter adaptation picked up from Neanderthal DNA; now scientists think this DNA may be responsible for high rates of Type-2 Diabetes in Native Americans.

4. Western diseases selected for Western immune responses

One of the interesting things about the Neanderthal DNA hanging around in people is that it appears to code for certain immune responses. West Hunter recently had a great post (TLRs, PAMPs, and Alley Oop) detailing how they work, but for our purposes, “provide immunity” is sufficient. Austin Whittall suggests that back when smallpox, influenza, measles, and all of the other Western diseases tore through the Native Americans, killing about 90% of them, the guys who had more Neanderthal DNA were more likely to survive because they were more likely to be immune to the same stuff as Europeans. By contrast, those Indians with less Neanderthal DNA may have had less immunity to the European diseases, and so been more likely to die, leaving behind a population of high-Neanderthal DNA people.

5. One thing we can say for sure: if the data’s correct, the peopling of the Americas was more complex than previously thought.

There are four areas of particular interest:

A. The highly Neanderthal area in the Pacific Northwest

B. The highly Denisovan area in Brazil

C. The low-Neanderthal area on the South American coast

D. The low-Neanderthal and low-Denisovan area along the Baja gulf in Mexico.

I’ve got nothing on A and C; supply your own theories.

6. Speculations on the origins of high-Denisovan people in Brazil:

A couple of papers in Science and Nature recently proposed that Melanesian-related people somehow made it to the rain forest long after the other Indians got to the area. West Hunter helpfully summarizes them.

West Hunter suggests that the Melanesian-related people with their high-Denisovan DNA got to the Americas first, and were then replaced throughout the continents by later invaders, the ancestors of current Indians. The one place the Melanesian-related people managed to survive was in the depths of the rainforest, a very difficult place to conquer. Even today, there are “uncontacted tribes” living in the Amazon rainforest; if anywhere were a good spot for a group of humans to avoid getting conquered, the depths of the rainforest is a good one.

7. The low-Neanderthal and low-Denisovan area along the Baja gulf in Mexico.

So what’s up with that? As far as I know, the only people who don’t have any Neanderthal or Denisovan are Africans. (And even there, there’s a little, just due to back-migration from the rest of the world.)

Are these people descended from a totally different group that came directly from Africa?

There’s a tiny ethnic group in the area, called the Seri:

Dona Ramona of the Seri Indians of Sonora, Mexico

According to the Wikipedia, the Seri speak a language isolate–that is, their language, like Basque, doesn’t appear to be related to any other language on Earth–and they are not culturally connected with any of their neighbors. They’ve also held out significantly against Spanish and Mexican assimilation. In other words, they might very well be a totally isolated population that is not related at all to any of their neighbors.

Some more information on the Seris.

Then I found this interesting map:

maps showing global distribution of the HLA-B*73:01 allele

I found these maps over on Austin Whittall’s post on Denisovans and America.

Looks like the same spot, doesn’t it?

The two different “real” maps how different things because they come from different scientists who came up with different data, but the overall picture is similar–if you look closely, both maps show a hotspot in Israel, for example. The second map looks less detailed, (hence their miss of several Middle Eastern hotspots,) but has a wider global range, which is obviously useful for our purposes. They also help show the importance of not putting too much stock in any single study about the distribution of a particular gene or allele or whathaveyou; different scientists come up with different numbers.

At any rate, while this could be just a totally random coincidence, if it isn’t, it’s awfully interesting, isn’t it? I know the Egyptians circumnavigated Africa; the Carthaginians and Phoenicians were also noted sea-farers. Or perhaps some other group I know nothing about from the region, before folks started keeping good records. Who knows?

8. Other people’s theories: Neanderthals, Denisovans, and H erectus made it to America before we did, and H Sapiens intermixed with them after they arrived; humans evolved in American, and then migrated to the rest of the world from there.