Page 2 of 3 FirstFirst 123 LastLast
Results 11 to 20 of 24

Thread: Modern Nilotic Dinka wrong proxy for ancient African admixture in East Africans?

  1. #11
    Registered Users
    Posts
    165
    Sex

    United Nations African Union
    Turns out my initial post was correct after all. This study tested the hypothesis of African ancestry in HOA populations being derived from or not being differenitiated from the Nilo-Saharan(Dinkas) and came to the conclusion that the African ancestry in HOA are actually distinct. The African ancestry of HOA derive from a distinct African population.

    https://journals.plos.org/plosgeneti...l.pgen.1004393

    The hypothesis that African ancestry in the HOA is not distinct from that found in neighboring Nilo-Saharan speaking populations (hypothesis 1A above) requires a history of homogenizing inter-population migration or relatively recent common origin. In the case of homogenizing gene flow, a correlation between genetic and geographic distance might be expected, with nearby populations more alike than distant populations. We calculated within and between population gene identity (the probability that two randomly drawn alleles are identical by state) for all the populations included in the 4K partitioned dataset. We then used the between population gene identity estimates among the predominantly Nilo-Saharan ancestry Anuak, Gumuz, South Sudanese, and the African ancestry partition of the Amhara, Ari, Oromo, Somali, and Tygray to test for a relationship between genetic and geographic distance. No significant relationship was recovered (Mantel test, r = −0.28, p = 0.185) (Figure 3A).

    Since the pattern of genetic variation in the African ancestry of Sudanese and HOA populations is not a good fit to one model of ongoing gene flow, we tested the hypothesis that there is population substructure within and between HOA and Nilo-Saharan populations using AMOVA [65] and hierarchical population tree models [66], [67]. First, within the HOA we used AMOVA to test for differentiation between linguistic groups – the Omotic speaking Ari, the Semitic speaking Amhara and Tygray, and the Cushitic speaking Oromo and Somali – and found a significant difference (ΦGT = 0.013, p<0.001). We also fit the HOA data to two population tree models, one without substructure and one with linguistically defined subgroups (Figure 3, and found that the tree with the linguistic groups is a significantly better fit to the data (K = 30, df = 1, p = 4.310−8). Next, we tested for the presence of linguistically delineated subgroups within the Anuak, Gumuz, and South Sudanese. Most southern Sudanese populations speak languages in the Nilotic branch of the Nilo-Saharan language family and the Anuak language is also a Nilotic language [68]. The Gumuz language is either a highly divergent Nilo-Saharan language or a language isolate [69]. AMOVA reveals a statistically significant difference between these linguistic groups (ΦGT = 0.024, p<0.001) and the population tree with linguistically defined subgroups (Figure 3C) is a significantly better fit to the data than the tree without subgroups (K = 132, df = 1, p≈0). Finally, putting all of the populations together in an AMOVA analysis, we find significant differences between linguistic subgroups at both a macro level (Nilo-Saharan vs Afro-Asiatic) (ΦGT = 0.014, p<0.0001) and a micro level (Nilotic, Gumuz, Omotic, Semitic, Cushitic) (ΦGT = 0.022, p<0.0001). Population tree models with these groupings are a significantly better fit to the data than a tree without subgroups (K = 415 and 264, df = 1, p≈0) (Figure 3D). The tree with the larger subgroups (Nilo-Saharan vs Afro-Asiatic) is a slightly better fit to the data (Λ = 662) than the tree with the smaller subgroups (Λ = 812; smaller Λ values indicate better fit).

    These results support the hypothesis from ADMIXTURE K≥11 of a distinct African ancestry with a long history in differentiated HOA populations (hypothesis 1B above) over the hypothesis from ADMIXTURE K≤10 that African ancestry in the HOA is not substantially differentiated from that found in neighboring populations (hypothesis 1A). In fact, our results suggest a rather more complicated history for these regional populations. Studies of further population samples from ethnic groups in and near the western and southern edges of the Ethiopian escarpment are sure to be interesting.
    Last edited by Mirix; 05-08-2021 at 05:09 PM.

  2. #12
    Registered Users
    Posts
    165
    Sex

    United Nations African Union
    Forgot to add this from the study , as it is significant:

    After partitioning the SNP data into African and non-African origin chromosome segments, we found support for a distinct African (Ethiopic) ancestry
    and a distinct non-African (Ethio-Somali) ancestry in HOA populations. The African Ethiopic ancestry is tightly restricted to HOA populations and likely represents an autochthonous HOA population.
    Because there is archaeological, historical, and linguistic evidence for contact with non-African populations beginning about 3,000 years ago, it has often been assumed that the non-African ancestry in HOA populations dates to this time. In this work, we find that the genetic composition of non-African ancestry in the HOA is distinct from the genetic composition of current populations in North Africa and the Middle East. With these data, we demonstrate that most non-African ancestry in the HOA cannot be the result of admixture within the last few thousand years, and that the majority of admixture probably occurred prior to the advent of agriculture.
    The non-African ancestry in the HOA, which is primarily attributed to a novel Ethio-Somali inferred ancestry component, is significantly differentiated from all neighboring non-African ancestries in North Africa, the Levant, and Arabia. The Ethio-Somali ancestry is found in all admixed HOA ethnic groups, shows little inter-individual variance within these ethnic groups, is estimated to have diverged from all other non-African ancestries by at least 23 ka, and does not carry the unique Arabian lactase persistence allele that arose about 4 ka. Taking into account published mitochondrial, Y chromosome, paleoclimate, and archaeological data, we find that the time of the Ethio-Somali back-to-Africa migration is most likely pre-agricultural.
    http://journals.plos.org/plosgenetic...l.pgen.1004393

    All the "Dinka Like" related claims are out the water it seems. Both the Non-African and African ancestry in the HOA population is distinct and tightly restricted to the Horn of African populations heavily differentiated from all other neighboring African and Non-African populations and African ancestry represents an autochtonous(indigenous) HOA population . And the study accounted this for by homogenizing gene flow. This significantly removes skewed admixture results and formation of false proxies that created the Dinka/Nilote associations to begin with. Which i related about in my first two posts.

    The last part about the non-African ancestry being pre-agricultutre accords well with the linguistic and archeological evidence of the antiquity of Agriculture in HOA and Ehret shows how it owes nothing to Arabian introduction or influence. . On the Antiquity of Agriculture in Ethiopia. It was often assumed by people that agriculture in the Horn of Africa owes much to South Arabian influence and migrations.

  3. #13
    Registered Users
    Posts
    229
    Sex
    Location
    Canada
    Ethnicity
    Somali
    Y-DNA (P)
    T-L208
    mtDNA (M)
    N1b2

    Canada Somaliland
    Quote Originally Posted by Mirix View Post
    Forgot to add this from the study , as it is significant:





    http://journals.plos.org/plosgenetic...l.pgen.1004393

    All the "Dinka Like" related claims are out the water it seems. Both the Non-African and African ancestry in the HOA population is distinct and tightly restricted to the Horn of African populations heavily differentiated from all other neighboring African and Non-African populations and African ancestry represents an autochtonous(indigenous) HOA population . And the study accounted this for by homogenizing gene flow. This significantly removes skewed admixture results and formation of false proxies that created the Dinka/Nilote associations to begin with. Which i related about in my first two posts.

    The last part about the non-African ancestry being pre-agricultutre accords well with the linguistic and archeological evidence of the antiquity of Agriculture in HOA and Ehret shows how it owes nothing to Arabian introduction or influence. . On the Antiquity of Agriculture in Ethiopia. It was often assumed by people that agriculture in the Horn of Africa owes much to South Arabian influence and migrations.
    The distinct Ethiopic ancestry they're talking about in that study is Mota-like ancestry which is incredibly diluted in most Horner Cushitic and Ethio-Semitc speakers who are all predominantly Dinka-like with the exception of the Oromo who have nearly equal amounts of Mota and Dinka ancestry (likely due to admixture from Omotic speakers)

    Nevertheless Mota-like and Nilotic populations all seem to be deeply related with Mota having deeper African and OOA affinities.

    From what I've seen it seems like the Horn has become progressive more Dinka-like over time with the specific Early_Pastoral Neolithic sample that seems to be ancestral to most of the following populations serving as the starting point.

    The Dinka themselves also seem to have received extra Central and/or West African ancestry which makes them imperfect fits for the Dinka-like ancestry in Horners.

  4. The Following 7 Users Say Thank You to Mnemonics For This Useful Post:

     Alfa (05-13-2021),  diini95 (05-15-2021),  drobbah (05-13-2021),  gihanga.rwanda (05-13-2021),  Lenny Nero (05-19-2021),  NetNomad (05-18-2021),  pgbk87 (05-13-2021)

  5. #14
    Registered Users
    Posts
    165
    Sex

    United Nations African Union
    Quote Originally Posted by Mnemonics View Post
    The distinct Ethiopic ancestry they're talking about in that study is Mota-like ancestry which is incredibly diluted in most Horner Cushitic and Ethio-Semitc speakers who are all predominantly Dinka-like with the exception of the Oromo who have nearly equal amounts of Mota and Dinka ancestry (likely due to admixture from Omotic speakers)

    Nevertheless Mota-like and Nilotic populations all seem to be deeply related with Mota having deeper African and OOA affinities.

    From what I've seen it seems like the Horn has become progressive more Dinka-like over time with the specific Early_Pastoral Neolithic sample that seems to be ancestral to most of the following populations serving as the starting point.

    The Dinka themselves also seem to have received extra Central and/or West African ancestry which makes them imperfect fits for the Dinka-like ancestry in Horners.
    My point was their admixture have skewered results which has led people to formulate admixture hypothesis using modern populations some people have tried to hypothesize that it is from an Nilotic Dinka sources (Which people in this forum accept without question) and subsequently used it as a proxy. In study i have shown above they divided the Ethio-Somali samples from all other African population samples. and they divided/groupe the HOA DNA into African and Non-African. The African DNA they found to be distinct and highly differentiated . They tested it against the Dinka hypothesis that like i explained on the first page and in the 2nd post above you


    It confirms the reason why Dinka populations scores well it's because they are actually admixed populations themselves from cushites(who introduced in them non-African related ancestry) and not purely African and that just gives you distorted African ancestry proportions that is not accounted for. It may not actually show an actual relationship at all but a percieved one created by failing to take account of that. When you do take that into account by homogenizing the gene flow or control for relatively recent origin it removes that distortion so that you can get a clearer picture. What they found was no significant relationship. The African ancestry in HOA highly differentiate and distinct from the neighboring Nilo-Saharan speaking populations.


    The Early Pastoral Neolithic could be good candidate for the source of West Euroasian ancestry for HOA i must say.
    Last edited by Mirix; 05-13-2021 at 03:38 PM.

  6. #15
    Registered Users
    Posts
    229
    Sex
    Location
    Canada
    Ethnicity
    Somali
    Y-DNA (P)
    T-L208
    mtDNA (M)
    N1b2

    Canada Somaliland
    Quote Originally Posted by Mirix View Post
    My point was their admixture have skewered results which has led people to formulate admixture hypothesis using modern populations some people have tried to hypothesize that it is from an Nilotic Dinka sources (Which people in this forum accept without question) and subsequently used it as a proxy. In study i have shown above they divided the Ethio-Somali samples from all other African population samples. and they divided/groupe the HOA DNA into African and Non-African. The African DNA they found to be distinct and highly differentiated . They tested it against the Dinka hypothesis that like i explained on the first page and in the 2nd post above you


    It confirms the reason why Dinka populations scores well it's because they are actually admixed populations themselves from cushites(who introduced in them non-African related ancestry) and not purely African and that just gives you distorted African ancestry proportions that is not accounted for. It may not actually show an actual relationship at all but a percieved one created by failing to take account of that. When you do take that into account by homogenizing the gene flow or control for relatively recent origin it removes that distortion so that you can get a clearer picture. What they found was no significant relationship. The African ancestry in HOA highly differentiate and distinct from the neighboring Nilo-Saharan speaking populations.


    The Early Pastoral Neolithic could be good candidate for the source of West Euroasian ancestry for HOA i must say.
    The Dinka are very unlikely to be admixed with Cushitic populations. They seem to be less Neanderthal than the Yoruba and they lack a strong preference for West Eurasians over East Eurasians, which would be present if they were Cushitic admixed.

    Regardless of whether or not the Dinka themselves contributed to Horn populations it is very evident that Horner populations have become more Dinka-like overtime which is impossible if you believe that this affinity is because of admixture from Cushitic populations to the Dinka.

    The Early pastoralist who seems to be ancestral to the latter PN populations has rather minor Dinka affinity (8-15%) and is one of the most Natufian samples we have period.

    The later pastoralists on the other had are mostly an even split between Dinka-like and Mota-like ancestry ( excluding the less Eurasian ones who are obviously admixed with additional Mota-like hunter gatherer ancestry)

    Modern Horners are even more Dinka-like with the Amhara, Tigray, and Ethiopian Somalis showing high to medium single digits of Mota ancestry and the Somalis from Somalia proper showing even less.

    This pattern wouldn't be present if we assume that any affinity between the populations was from Cushitic admixture into the Dinka.

  7. The Following 7 Users Say Thank You to Mnemonics For This Useful Post:

     Alfa (05-14-2021),  Angoliga (05-13-2021),  drobbah (05-13-2021),  Keneki20 (05-14-2021),  pegasus (05-13-2021),  pgbk87 (05-13-2021),  Typic (05-15-2021)

  8. #16
    Registered Users
    Posts
    165
    Sex

    United Nations African Union
    Quote Originally Posted by Mnemonics View Post
    The Dinka are very unlikely to be admixed with Cushitic populations. They seem to be less Neanderthal than the Yoruba and they lack a strong preference for West Eurasians over East Eurasians, which would be present if they were Cushitic admixed.

    Regardless of whether or not the Dinka themselves contributed to Horn populations it is very evident that Horner populations have become more Dinka-like overtime which is impossible if you believe that this affinity is because of admixture from Cushitic populations to the Dinka.

    The Early pastoralist who seems to be ancestral to the latter PN populations has rather minor Dinka affinity (8-15%) and is one of the most Natufian samples we have period.

    The later pastoralists on the other had are mostly an even split between Dinka-like and Mota-like ancestry ( excluding the less Eurasian ones who are obviously admixed with additional Mota-like hunter gatherer ancestry)

    Modern Horners are even more Dinka-like with the Amhara, Tigray, and Ethiopian Somalis showing high to medium single digits of Mota ancestry and the Somalis from Somalia proper showing even less.

    This pattern wouldn't be present if we assume that any affinity between the populations was from Cushitic admixture into the Dinka.
    What do you mean unlikely to be mixed? Have you actually read my opening post? And its not unlikely at all when they are neighboring population to Afro-Asiatic speakers in the nile valley they could very well have experienced gene flow from.

    Several studies do in fact show that they do carry West Euro Asian paternal haplogroups common to cushitic/Afroc-Asiatic speaking populations. For example in the study on Restricted Gene flow among the Sudanese made by Hassan et al. (2008) observed that around 20% of Shilluk and 15% of Dinka individuals bear the E1b1b/E3b haplogroup, a paternal clade that is most common among Afro-Asiatic speakers. Most strikingly, Balemi (2018) reports that 51.62% of his Nuer sample from southwestern Ethiopia carry the E1b1b-M78 haplogroup, compared to 16.67% of Hassan et al.

    And then another Genome analysis detecting almost 30% non-African ancestry in a sample of Dinka. This Nilotic population was previously assumed to have little-to-no non-African ancestry, and was therefore often used as a proxy for inferring African ancestry (Skoglund et al. (2017))

    Can you define what Dinka Like actually means? because you just repeat it over and over . The African Ancestry in Horn of Africans don't bear any relationship with the neighboring Nilo-Saharan populations as the study i qouted above you shows and when taken with homogenizing of gene flow and controlling for recent common origin they found that it was actually distinct from it. So the question remains how would they be Dinka like ?

    ''Dinka like" sounds like just an assumption being made here considering the above evidence shows Nilo-Saharan populations being considerably admixed with AA populations.

  9. #17
    Registered Users
    Posts
    229
    Sex
    Location
    Canada
    Ethnicity
    Somali
    Y-DNA (P)
    T-L208
    mtDNA (M)
    N1b2

    Canada Somaliland
    Quote Originally Posted by Mirix View Post
    What do you mean unlikely to be mixed? Have you actually read my opening post? And its not unlikely at all when they are neighboring population to Afro-Asiatic speakers in the nile valley they could very well have experienced gene flow from.

    Several studies do in fact show that they do carry West Euro Asian paternal haplogroups common to cushitic/Afroc-Asiatic speaking populations. For example in the study on Restricted Gene flow among the Sudanese made by Hassan et al. (2008) observed that around 20% of Shilluk and 15% of Dinka individuals bear the E1b1b/E3b haplogroup, a paternal clade that is most common among Afro-Asiatic speakers. Most strikingly, Balemi (2018) reports that 51.62% of his Nuer sample from southwestern Ethiopia carry the E1b1b-M78 haplogroup, compared to 16.67% of Hassan et al.

    And then another Genome analysis detecting almost 30% non-African ancestry in a sample of Dinka. This Nilotic population was previously assumed to have little-to-no non-African ancestry, and was therefore often used as a proxy for inferring African ancestry (Skoglund et al. (2017))

    Can you define what Dinka Like actually means? because you just repeat it over and over . The African Ancestry in Horn of Africans don't bear any relationship with the neighboring Nilo-Saharan populations as the study i qouted above you shows and when taken with homogenizing of gene flow and controlling for recent common origin they found that it was actually distinct from it. So the question remains how would they be Dinka like ?

    ''Dinka like" sounds like just an assumption being made here considering the above evidence shows Nilo-Saharan populations being considerably admixed with AA populations.
    I suppose I should have been more clear. The Dinka are unlikely to have "significant" admixture from the Horn. The Gumuz are an excellent example of Nilotic population that have minor but significant admixture from Horner-like populations.

    When I'm talking about Dinka-like ancestry I am referring to the specific strain of AEA ancestry that peaks in Nilotic populations. It is very distinct from the native Mota-like ancestry found in the Horn dispite both populations being likely very related.

    Let us assume that you are correct and that the Dinka have large amounts of Horner ancestry, you have to answer three very important questions.

    Why do they lack the strong preference for West Eurasians present in Horners?

    This is important because if they were significantly admixed with West Eurasian ancestry they should strongly prefer Ancient West Eurasians strongly over East Eurasians. You could get around that by assigning a special relationship between their non-Horner admixture and East Eurasians but that is not a particularly parsimonious explanation.

    Why do they have slightly less Neanderthal than Yoruba?

    Neanderthal can act as a sort of tracer dye for Eurasian ancestry which allows us to determine if a population has significant Crown Eurasian ancestry. Horners obviously have Neanderthal ancestry proportional to their Eurasian admixture. The Dinka on the other hand seem to have a lower affinity to Neanderthals as compared to the Yoruba.

    If we assume that the African ancestors of the Dinka got all of their Neanderthal from Horner populations (which is incredibly unlikely considering they have a minor affinity to Iberomaurusians) we are looking at a peak of about 10-20% Horner admixture which would not explain the strength of the admixture models and has also some how left no strong affinity for Ancient West Eurasians.

    Why does the affinity to Dinka increase in the Horn?

    Populations in the Horn seem to have gotten more Dinka-like overtime with Early_PN followed by Kenya_PastoralN and then Kenya_PastoralIA, each of which is more Dinka-like than the last.

    How is this occurring if admixture did not occur?
    We already know that Mota like populations were native to the Horn and the existence of the Southeast African cline confirms that this population was relatively old in the region. Which means that the the various pastoralists populations got successively less native overtime.

    Is that possible without admixture from an external source?


    The presence of uniparentals like E1b1b in Nilotic populations are pretty easily explained by founder effects after minor admixture from neighboring pastoralists. But, everything else cannot be explained by your thesis.
    Last edited by Mnemonics; 05-15-2021 at 10:50 PM. Reason: Formatting

  10. The Following 5 Users Say Thank You to Mnemonics For This Useful Post:

     Alfa (05-16-2021),  diini95 (05-15-2021),  drobbah (05-15-2021),  Keneki20 (05-15-2021),  pegasus (05-16-2021)

  11. #18
    Registered Users
    Posts
    1,867
    Sex

    Quote Originally Posted by Mnemonics View Post
    I suppose I should have been more clear. The Dinka are unlikely to have "significant" admixture from the Horn. The Gumuz are an excellent example of Nilotic population that have minor but significant admixture from Horner-like populations.

    When I'm talking about Dinka-like ancestry I am referring to the specific strain of AEA ancestry that peaks in Nilotic populations. It is very distinct from the native Mota-like ancestry found in the Horn dispite both populations being likely very related.

    Let us assume that you are correct and that the Dinka have large amounts of Horner ancestry, you have to answer three very important questions.

    Why do they lack the strong preference for West Eurasians present in Horners?

    This is important because if they were significantly admixed with West Eurasian ancestry they should strongly prefer Ancient West Eurasians strongly over East Eurasians. You could get around that by assigning a special relationship between their non-Horner admixture and East Eurasians but that is not a particularly parsimonious explanation.

    Why do they have slightly less Neanderthal than Yoruba?

    Neanderthal can act as a sort of tracer dye for Eurasian ancestry which allows us to determine if a population has significant Crown Eurasian ancestry. Horners obviously have Neanderthal ancestry proportional to their Eurasian admixture. The Dinka on the other hand seem to have a lower affinity to Neanderthals as compared to the Yoruba.

    If we assume that the African ancestors of the Dinka got all of their Neanderthal from Horner populations (which is incredibly unlikely considering they have a minor affinity to Iberomaurusians) we are looking at a peak of about 10-20% Horner admixture which would not explain the strength of the admixture models and has also some how left no strong affinity for Ancient West Eurasians.

    Why does the affinity to Dinka increase in the Horn?

    Populations in the Horn seem to have gotten more Dinka-like overtime with Early_PN followed by Kenya_PastoralN and then Kenya_PastoralIA, each of which is more Dinka-like than the last.

    How is this occurring if admixture did not occur?
    We already know that Mota like populations were native to the Horn and the existence of the Southeast African cline confirms that this population was relatively old in the region. Which means that the the various pastoralists populations got successively less native overtime.

    Is that possible without admixture from an external source?


    The presence of uniparentals like E1b1b in Nilotic populations are pretty easily explained by founder effects after minor admixture from neighboring pastoralists. But, everything else cannot be explained by your thesis.
    I think these are good points, but wouldn't most of it be answered by the alternative of the Eurasian admixture being mostly (not exclusively) Basal Eurasian derived? This would also make E1b1b easier to explain. How would an admixture model with a population which is much more Basal Eurasian shifted than Natufians fare?

  12. The Following 2 Users Say Thank You to Riverman For This Useful Post:

     Alfa (05-16-2021),  Mnemonics (05-16-2021)

  13. #19
    Registered Users
    Posts
    229
    Sex
    Location
    Canada
    Ethnicity
    Somali
    Y-DNA (P)
    T-L208
    mtDNA (M)
    N1b2

    Canada Somaliland
    Quote Originally Posted by Riverman View Post
    I think these are good points, but wouldn't most of it be answered by the alternative of the Eurasian admixture being mostly (not exclusively) Basal Eurasian derived? This would also make E1b1b easier to explain. How would an admixture model with a population which is much more Basal Eurasian shifted than Natufians fare?
    His claim is that the Dinka are admixed with populations from the Horn, which would indicate that they are significantly West Eurasian and/or significant Mota like. Both of which are made unlikely by those factors.

    AEA is likely an admixed component itself but I doubt that is the result of recent admixture.

    I'm not even sure that "Basal Eurasian" proper exists anymore. The assumption that it exists is due to the inability of fstats to find significant relationships between Basal Eurasian rich populations and SSA populations but there is an obvious issue with the ability of the software to detect significant relationships between SSA populations and heavily admixed AEA rich populations like Kenya_PastoralN.

    It gets so bad that you can put two members of the same admixed African population in the fstat and get large significant stats for the Eurasian population even when you switch them.

  14. The Following 4 Users Say Thank You to Mnemonics For This Useful Post:

     Awale (05-16-2021),  Keneki20 (05-16-2021),  Lenny Nero (05-19-2021),  Riverman (05-16-2021)

  15. #20
    Registered Users
    Posts
    165
    Sex

    United Nations African Union
    Quote Originally Posted by Mnemonics View Post
    I suppose I should have been more clear. The Dinka are unlikely to have "significant" admixture from the Horn. The Gumuz are an excellent example of Nilotic population that have minor but significant admixture from Horner-like populations.
    When I'm talking about Dinka-like ancestry I am referring to the specific strain of AEA ancestry that peaks in Nilotic populations. It is very distinct from the native Mota-like ancestry found in the Horn dispite both populations being likely very related.
    Actually Gumuz according to Balemi (2018) 55.55% and 33.33% of Balemi (2018)’s Berta and Gumuz samples, respectively, bear the Eurasian F-M89 clade.

    But it is not just Gumuz or Dinka , for example Non (2010) likewise notes that over 40% of her Sudanese Nuer sample belongs to the mtDNA haplogroups M and N, including around 18% M1 carriers (cf. Table 3-3). The M1 subclade has been found in ancient Maghreban, Egyptian and South Cushitic specimens, and still remains a signature maternal lineage among the modern Afro-Asiatic-speaking populations in Northeast Africa.

    In short, uniparental markers indicate that there was significant gene flow from Afro-Asiatic-speaking groups (especially Cushitic speakers) into neighboring Nilote communities.

    Can you expand on the specific AEA ancestry?

    Let us assume that you are correct and that the Dinka have large amounts of Horner ancestry, you have to answer three very important questions.

    Why do they lack the strong preference for West Eurasians present in Horners? This is important because if they were significantly admixed with West Eurasian ancestry they should strongly prefer Ancient West Eurasians strongly over East Eurasians. You could get around that by assigning a special relationship between their non-Horner admixture and East Eurasians but that is not a particularly parsimonious explanation.
    Why do they have slightly less Neanderthal than Yoruba? Neanderthal can act as a sort of tracer dye for Eurasian ancestry which allows us to determine if a population has significant Crown Eurasian ancestry. Horners obviously have Neanderthal ancestry proportional to their Eurasian admixture. The Dinka on the other hand seem to have a lower affinity to Neanderthals as compared to the Yoruba. If we assume that the African ancestors of the Dinka got all of their Neanderthal from Horner populations (which is incredibly unlikely considering they have a minor affinity to Iberomaurusians) we are looking at a peak of about 10-20% Horner admixture which would not explain the strength of the admixture models and has also some how left no strong affinity for Ancient West Eurasians.
    Aren't these assumptions being made here on your part?. Because we are extrapulating on populations that was assumed to be less admixed then before. For example in various autosomal DNA studies, the northern Nilotes have appeared to be almost completely of African ancestry. For example, in the African Genome Variation Project’s analysis, the Dinka sample showed no extraneous influence at K=2 (cf. Gurdasani et al. (2015))

    But on the studies i have shown above that proves to not be the case.


    Why does the affinity to Dinka increase in the Horn?

    Populations in the Horn seem to have gotten more Dinka-like overtime with Early_PN followed by Kenya_PastoralN and then Kenya_PastoralIA, each of which is more Dinka-like than the last.

    How is this occurring if admixture did not occur?
    We already know that Mota like populations were native to the Horn and the existence of the Southeast African cline confirms that this population was relatively old in the region. Which means that the the various pastoralists populations got successively less native overtime.

    Is that possible without admixture from an external source?


    The presence of uniparentals like E1b1b in Nilotic populations are pretty easily explained by founder effects after minor admixture from neighboring pastoralists. But, everything else cannot be explained by your thesis.

    The presence of uniparentals are more likely to have come ancient Cushites . In 2017, Skoglund et al. compared the same AGVP Dinka sample to that of an ancient South Cushitic pastoralist (Luxmanda), the first such specimen to be genetically analyzed.

    In their admixture analysis, the Dinka individuals now all of a sudden showed almost 30% non-African ancestry at the K=2 level. Judging by the existing uniparental marker data, it’s pretty clear why that is: there was non-African ancestry buried within the northern Nilote gene pool, and that ancestry was specifically derived from earlier Cushitic peoples such as Luxmanda.

    If there is any percieved affinity it could easily be explained when taking the above information in. This taking to together with the fact the ancient Cushitic specimens are devoid of West African affinity , makes modern Nilotic individuals unrealistic proxies for inferring an African admixture component among the ancient Cushitic settlers of the Pastoral Neolithic.

Page 2 of 3 FirstFirst 123 LastLast

Similar Threads

  1. Ancient Swahili East African coins found in Australia
    By SWAHILLI_PRINCE16 in forum African
    Replies: 0
    Last Post: 10-25-2019, 09:25 PM
  2. Replies: 13
    Last Post: 07-29-2019, 09:52 PM
  3. Replies: 12
    Last Post: 02-22-2019, 06:12 AM
  4. African admixture in ancient Europeans
    By sciencediver in forum Ancient (aDNA)
    Replies: 17
    Last Post: 03-08-2016, 04:34 PM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •