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Thread: The analysis of racial structure of early dynastic populations in Egypt2410 days old

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    Quote Originally Posted by Ether View Post
    If the Omotic cluster is merely a pseudo-Hadza component with minor Afrasan, it would explain the phenomenon observed by beyoku.
    What makes Omotics similar to Hadza? Hadza Y-DNA is mainly B, with some (presumably recent) E-M2 from Bantus, and E-M35 from Cushites. Whereas E-M329 seems like the characteristic Omotic Y-DNA, and B is generally rare/absent in Ethiopia. Mitochondrial lineages don't match either, as Hadza are mostly L4.

    Omotic admixture presumably does influence hair texture in highlanders, but I'd say there was probably significant selection in Somalis (and Afars?) as well. Autosomally, Somalis are roughly intermediate between Nilo-Saharans and Arabians, but this doesn't really match their hair texture (if anything, it probably matches the varying hair texture of Habeshas better).

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    Quote Originally Posted by Lol_Race View Post
    What makes Omotics similar to Hadza? Hadza Y-DNA is mainly B, with some (presumably recent) E-M2 from Bantus, and E-M35 from Cushites. Whereas E-M329 seems like the characteristic Omotic Y-DNA, and B is generally rare/absent in Ethiopia. Mitochondrial lineages don't match either, as Hadza are mostly L4.
    When a non-admixed Hadza is used alone in an East African focused run the predominant cluster in such individuals is always the Omotic cluster and not the Nilo-Saharan, Khoisan or other clusters. It looks like the Omotic cluster has strong shared ancestry with the Hadza.

    Quote Originally Posted by Lol_Race View Post
    Omotic admixture presumably does influence hair texture in highlanders, but I'd say there was probably significant selection in Somalis (and Afars?) as well. Autosomally, Somalis are roughly intermediate between Nilo-Saharans and Arabians, but this doesn't really match their hair texture (if anything, it probably matches the varying hair texture of Habeshas better).
    I am not sure if modern Nilo-Saharans are good proxies for pre-Omotic & pre-West Eurasian introgressed Cushites. All Nilo-Saharans have substantial levels of the pygmoid cluster in Polako's recent K=8 global run while absent in Horners. Similar patterns and anomalies are observed in other studies too. The purely Sub-Saharan predecessors of Cushites probably don't exist today.

    Speculatively, they were likely very dark and facially similar to the Nilotes but without the extreme peppercorn hair and probably a lower median nasal index.

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    Quote Originally Posted by Ether View Post
    I am not sure if modern Nilo-Saharans are good proxies for pre-Omotic & pre-West Eurasian introgressed Cushites. All Nilo-Saharans have substantial levels of the pygmoid cluster in Polako's recent K=8 global run while absent in Horners. Similar patterns and anomalies are observed in other studies too. The purely Sub-Saharan predecessors of Cushites probably don't exist today.
    Nilo-Saharans themselves are not at all a representation of the East African ancestry in Horners, that's true. But it's just clear that there's a component that peaks in them in many ADMIXTURE runs that makes up the entirety of the non-Omotic EA in Horners. But this component doesn't make up 100% of an Anuak for example but like 70 to 90% of their ancestry IIRC.

    Horners aren't descended from people exactly like Nilo-Saharans, we just share a lot of pre-historic ancestry with them/ a component that peaks in them makes up half to more than half of the ancestry in most Horners. So yeah, they're not exactly a good proxy...

    But what Lol_Race is implying is that Nilo-Saharans are a mostly non-Eurasian admixed East African population so Somalis/ Horners = straddling between such a population and Arabians.
    Last edited by Awale; 2015-05-14 at 21:54.

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    Quote Originally Posted by Ether View Post
    When a non-admixed Hadza is used alone in an East African focused run the predominant cluster in such individuals is always the Omotic cluster and not the Nilo-Saharan, Khoisan or other clusters. It looks like the Omotic cluster has strong shared ancestry with the Hadza.
    That doesn't mean Omotic has strong shared ancestry with Hadza. Omotics and Nilo-Saharan are clearly very divergent populations; the fact that Hadza tend to prefer Omotic when forced to choose between the two, in the few runs available, doesn't necessarily mean anything.

    Quote Originally Posted by Ether
    I am not sure if modern Nilo-Saharans are good proxies for pre-Omotic & pre-West Eurasian introgressed Cushites. All Nilo-Saharans have substantial levels of the pygmoid cluster in Polako's recent K=8 global run while absent in Horners. Similar patterns and anomalies are observed in other studies too. The purely Sub-Saharan predecessors of Cushites probably don't exist today.

    Speculatively, they were likely very dark and facially similar to the Nilotes but without the extreme peppercorn hair and probably a lower median nasal index.
    South Sudanese have significant Y-DNA B shared with Pygmies, and mtDNA L1/L5 shared with the Pygmies to the south. OTOH, B was apparently lacking in proto-Cushites based on the modern distribution. Interestingly, ancient North Sudanese had high levels of A and lacked B. Proto-Cushites carried A3b2 but not B to the HOA, and proto-Cushites likely migrated through Sudan to the Horn.

    While I agree that the SSA ancestors of Cushites are extinct, I don't see any reason to project the divergent features of modern Somalis to their SSA ancestors. Habeshas/highlanders are still mostly Cushitic. Even though Omotic admixture would lead to more tightly coiled hair, Habeshas have at least as much additional ME admixture (significantly more, assuming a Somali-like "Cushitic" ancestral population) to cancel out the Omotic. So some selection in the ancestors of Somalis is required to explain the difference in phenotype.

    Some estimates from Awale's blog give Tigrinyas 66% "Cushitic" (Somali), 12% Omotic, 22% West Asian, Amharas get 16% Omotic 21% West Asian.

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    I personally doubt it is selection instead of ancestral as the texture serves no real evolutionary benefit in tropical arid climates. Might see the case for cold northern climates, but not really in sunny tropical arid environments.

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    Quote Originally Posted by Ether View Post
    I personally doubt it is selection instead of ancestral as the texture serves no real evolutionary benefit in tropical arid climates. Might see the case for cold northern climates, but not really in sunny tropical arid environments.
    Selection can sometimes be random.

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    Quote Originally Posted by Awale View Post
    Selection can sometimes be random.
    Even for such conspicuous traits? Any examples?

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    There is also sexual selection, like with blue eyes in Europeans. Or just random chance. Somalis are a bottlenecked population, after all.

    Or are you suggesting the African ancestors of Cushites lived in a cold northern climate?

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    Quote Originally Posted by Ether View Post
    Even for such conspicuous traits? Any examples?
    Hmm, I can't think of an example off the top of my head but it's not like Habeshas went full on nappy haired. Instead they merely display a higher prevalence of such hair textures. The majority of Habeshas from what I can tell are still mostly "soft curly haired" (with varying degrees of how soft soft is) and that hair texture is the average among all Horners in my experience. It's entirely possibly that Omotic admixture just facilitated such hair textures becoming more common; again nappy/ very tightly coiled hair is not the norm among Habeshas at all. Just like straight hair while it can happen among Somalis more is still a rare trait.

    On second thought:

    Quote Originally Posted by Lol_Race View Post
    There is also sexual selection, like with blue eyes in Europeans. Or just random chance. Somalis are a bottlenecked population, after all.

    Or are you suggesting the African ancestors of Cushites lived in a cold northern climate?
    ^ This...
    Last edited by Awale; 2015-05-14 at 23:25.

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    It's not just Somalis who show this bias, but also Afars and to a lesser degree Eastern Oromos. The only reasonable correlation I see is lower Omotic ancestry.

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