Wednesday, March 25, 2015

East Eurasians: Ones you don't know about

East Eurasians aren't what you're thinking of right now, at least not entirely. I'm not referring to the Han Chinese, Japanese, Tibetans, Mongols or Southeast Asians exclusively here but the genetic entity/ grouping that prevails all over East Asia, Southeast Asia, pre-colonization Australia, the Pacific & even the Americas, Siberia, Central Asia & South Asia to some extent.

Japanese People

Above are essentially a people who epitomize what we all tend to think when we hear East Asian, and indeed ethnic Japanese, Han Chinese, Tibetans, Thai, Filipinos, Mongols & so on share in a strong genetic affinity for each other/ gross amounts of extremely ancient (pre-historic) shared ancestry & one may not be shocked by this based on their physical similarities (Phenotype).


What about the Andaman Islander man above with his child? Would you ever equate them genetically/ group them with East or Southeast Asians? 

Would it at all shock you if I told you that man and his child are closer to Japanese people than they are to Yorubas in West Africa or Dinkas in East Africa or Norwegians in Europe or Armenians in West Asia? Well, it's true... 

In fact that man and his child are not alone in their shared ancestry with East Asians being perhaps unexpected by some... Australian Aboriginals, Papuans, various Pacific Islander peoples & so on are all East Eurasians or in some papers such as more recent ones; Eastern Non-Africans (a naming that makes more sense since all of their home regions don't exactly correspond directly with what is known as the Eurasian continent).

Don't buy it? Well, the prolific and quite revolutionary study headed by Iosif Lazaridis [1] that studied ancient genomes from across Europe and utilized  low coverage data from individuals like MA-1 in Siberia to grant us a glimpse at European and frankly also West Eurasian ancestry clearly shows this data. That boy and what I assume is his father are from the Andaman Islands inhabited by groups such as The Great Andamanese, Onge, Jarawa & so and so. That boy and his father are Jarawas & the following woman- :

-is an Onge and please do take a clear look at what Onges are within this diagram of where various Human populations branch off from:

Native Americans like the Karitiana are known to now be a composite between Ancient North Eurasian (related to West Eurasian components like Western European Hunter-Gatherer) & East Asian-esque ancestry from several thousand years ago [2]. And that diagram is essentially saying what we've known for quite some time in population genetics; that the Onge branched off from the same source as East Asians like what makes up ~60% of the Karitiana's ancestry.

Regions of the Pacific Islands

This holds true for Pacific Islanders such as Melanesians, Polynesians and so on. Melanesians are known for having developed their own mutation for blonde hair [-] for example whilst being dark skinned and to your likely Western Culture raised eyes to looking African-esque:

Naturally Blonde, no European or West Asian admixture...

Pacific Islanders  have been studied-> even having as I recall a peer-reviewed paper dedicated to their autosomal DNA [3] and it finds the following clear data:

As you can see many groups across the Pacific Islands (colored orange & grey for example) prove closest to or the show greatest amount of affinity for East Asians like those from Taiwan though the Taiwanese often show an affinity for Southeast Asians whom they are linguistically similar to.

In fact here's a Papuan man:

And here is an Australian Aboriginal man:

I'm sure if you saw them across the street you'd associate them with 'Africa' (thinking they were "Black") and associating them genetically more with Japanese man or a Tibetan or a Filipino would be the last thing on your mind... But that is how things are, these two men's pre-historic ancestors branched off from a shared point of ancestry with East Asians' ancestry (the majority of both their ancestries anyway) Lazaridis et al. would for example dub Eastern Non-African or many know as East Eurasian.

In fact, on average, Papuans, Australian Aborigines and many Pacific Islanders show the weakest leanings toward Africans in a world population genetics sense. They are in terms of whole genome variance the most distinct/ "distant" from non-West Asian admixed (Horn Africans like Somalis, Habeshas etc.) continental Africans:


Yorubas are a Nigerian ethnic group who prove rather soundly representative of many Niger-Congo speaking groups across West Africa, for example; but, as you can see, Papuans prove more distinct from them than your average Frenchman or Han Chinese individual would (thought not by too much), though all these Human groups are nowhere near as distinct from each other as they are from a Neanderthal or Denisovan, for example.

Although it's assumed that the reason Papuans and Aborigines are somewhat more distinct is because they have a notable amount of Denisovan admixture just like many Eurasians, Americans and Eurasian admixed Africans at large have a very tiny but notable amount of Neanderthal admixture [11] with even Yorubas showing above zero (decimal range) levels of Neanderthal admixture. [5] The study that variance table is from even focuses on how they have Denisovan admixture... [4]

The admixture and how Papuans and Aboriginal Australians branched off from the "sub-source" as East Asians is demonstrated quite adequately in this following tree-mix owed to David Wesolowski (author of Eurogenes):

To give you an example in words: all Humans pretty much branched off from one shared point and it's thought that the Khoisan & African pygmies like the Mbuti branched off much earlier than the shared ancestry of the rest of us. Then, for example, Eurasians as I once explained diverged from an East African-related source and then that Proto-Eurasian source had various divergences one of which is Basal Eurasian which diverged from it earlier and then became isolated from other Eurasians (this is what's assumed, at least).

After that Ust-Ishim likely diverged from the shared ancestral point or state between East Eurasians & West Eurasians (majority of the ancestry in Europeans & West Asians, though they all have Basal Eurasian input) before or just when East & West Eurasian themselves diverged. [10] Onge, Australian Aborigines, Papuans, Melanesians like that dark skinned blonde boy/ their ancestors all supposedly diverged from "East Eurasian/Eastern Non-African" and so did the majority if not the entirety of the ancestry in the Japanese, Koreans, Tibetans and so on. 

Diverging to some extent from this point of ancestry not only through means like genetic drift but also through some Denisovan admixture which East Asians like Tibetans do have (though less than Papuans have). [6]

This ultimately slaughters the notion that these people are "Black" or somehow "African". Sure, all Eurasians (counting Native Americans and Pacific Islanders) ultimately trace back to Africa but these people do not have any special affinity for Africans or more recent African ancestry.

To be frank, many West Asians and North Africans have non-negligible levels of African admixture to begin with... Northwest Africans can vary between ~20 to ~25% African admixed (mostly East African with some Niger-Congo speaker-related admixture) despite some of their looks. [7] [8]

Moroccan man (Northwest African)

To be honest, even old-school racialists from the early modern period did not consider people such as those in Australia to be "like Africans" and didn't use the term "Negroid" to describe them. They instead dubbd them "Australoid" (their own "racial" classification). I normally don't laud these old racialists at all but here we agree in that even in terms of looks you can tell some of these people are not, for example, West-Central African or non-Cushitic admixed (Maasai [9]) Nilotic speakers. Instead their looks only superficially resemble those of Dinkas, Igbos, Madinkas and so on.

Find me a straight haired naturally blonde Igbo and we'll talk but I can find you a straight haired dirty blonde Australian aboriginal quite easily:

Even in terms of facial features and "physical morphology" there are clear distinctions to be made between these boys and some average Yoruba children but one shouldn't expect such aptitude from someone that's not an anthro-nut such as myself or people I am familiar with.

The big question here might be "Well, why do they look this way?" I mean sure, some only superficially resemble certain Africans (Africa's a big place with a lot of diversity and I'd be careful about referring to it as a monolith) but look at that Andamanese man & the child; they have nappy hair... They could pass in some places across Africa especially to layman eyes.

Well, I honestly do not know why they look the way they look but it's not input/ admixture from Africa or even a kind of Quasi-African (Basal Eurasian-esque) influence if even that could ever cause such looks-> I can only give you educated guesses like:

Natural Selection, bottle-necking or suffering through a Founder Effect [-] to make certain looks prevail grossly all of a sudden, there are tonnes of variables that play into this and their ancient ancestors may have looked nothing like this-> for all we know they all once resembled East Asians or even West Eurasians before these various East Eurasian (East Asian ones being counted) phenotypes developed.

But these peoples such as Papuans are East Eurasians plain and simple, perhaps with some Denisovan (a separate species of the genus Homo) admixture but by majority (little over ~95%) East Eurasian/ Eastern-Non-African in ancestry with a higher variance from Africans like Yorubas than you'd see from a Frenchman presumably thanks to their Denisovan admixture otherwise they'd likely be as varied from Africans as the Han & French are.

A world PCA showing you how they plot/ cluster with East Asians and much more distantly from non- Eurasian admixed East Africans or Niger-Congo Africans:

To consider these people "Black" in layman modern terms or like Africans is very disingenuous as they're closer to East Asians than anything else and closer to Europeans than a random Niger-Congo speaking non-Fulani African would be. Their looks, to me, really slap the idea of "racialism" in the face if one wishes to base it on phenotypes/physical-appearances as these people and East Asians like Koreans are closely related at least within the wider scheme of global diversity yet their looks are so starkly distinct.

Reference List:

6. Altitude adaptation in Tibetans caused by introgression of Denisovan-like DNA, Huerta-Sánchez et al.


1.  Southeast Asian genetics is a lot more complex then I hinted at in this blog post but I'll try to have a post out about it in time. If not I'll just say that for now it seems like certain Southeast Asians clearly have something of a South Asian-esque influence, from something akin to what Reich described as Ancestral South Indian (ANI) in an old peer-reviewed study form nearly seven years ago. F.e. Eurogenes K=8 lists a component similar to this as "South Eurasian" (Cambodians are composed of this by practically ~50%) to really get this component we'll need ancient genomes from South Asia though and South Eurasian as Eurogenes has it and "ANI" from Reich's study aren't exactly the same thing. ANI being a component that peaks in some of the southernmost populations of India such as the Paniya.

2. The bits on how Humans diverged is grossly over-simplified but it serves just fine in getting the point across for this blog post's subject matter.

Other genetics based literature on the Andamanese:

1 comment:

  1. Fascinating Awale the truths of the human genome are incredible and exciting. I wonder what the next step will be in understanding the genome.