15 ancestral components to bind them all

By Razib Khan | November 17, 2010 11:01 am

Dienekes Pontikos keeps chugging along, and has cranked out a new bar plot from the ADMIXTURE program with 15 putative ancestral components. He has “69 populations, and 1,189 individuals in total.” Most of these were assembled from public data, but some of them are particular to the Dodecad Ancestry Project. He contends:

In comparison to the K=10 analysis, the increased resolution allows us to:

- South Asians belonged primarily to the South Asian and West Asian components; this South Asian component spilt over to Iran and Central Asia. Now, a new Central-South Asian component, corresponding to the Ancestral North Indian of a recent study is inferred, and a corresponding South Indian component.

- HGDP Bedouins and Behar et al. (2010) Saudis take up their own component which I labeled Arabian. This appears to be a subset of the Southwest Asian component of the K=10 analysis

- There are several components in Siberian and Central Asian populations, alread discovered in my regional analysis. These are Central Siberian, Nganasan, Koryak, Chukchi, and Altaic which replace the K=10 Northeast Asian component

Not only has he generated a bar plot, but there is a PCA showing the relationship between the 15 ancestral groups, as well as a hierarchical tree. Since he references to the ANI and ASI of Reich et al., I thought I would note that the South Indian element from Dienekes’ K = 15 is still found in appreciable portions in the Turkic groups which earlier exhibited the South Asian component. And, on the PCA and phylogenetic tree it still clusters with West Eurasians more than East Eurasians, which is not the case with ASI (or the various Indian mtDNA lineages which coalesce back to a more recent common ancestor with East Eurasians).

The bar plot is below. Of interest are the most “pure” European groups, the Sardinians and Lithuanians. Also, compare Scandinavians and Finns.


ADMIXTURE15

CATEGORIZED UNDER: Genetics, History
  • http://dienekes.blogspot.com Dienekes

    ASI is not related to East Asians. This is evident, for example, in S2 Figure 1 of the Reich et al. paper, where most Indian groups (with the exception of a few Mongoloid-admixed ones) form a cline from _third_ pole towards Europeans, representing differential Caucasoid admixture.

    As Reich et al. note:

    “Many of the analyses in this study are based on modeling the history of Indo-European and
    Dravidian speaking groups of the Indian subcontinent in terms of a two-way historical mixture of
    an “Ancestral North Indian” (ANI) population that is genetically close to Central Asians, Middle
    Easterners, and Europeans, and an “Ancestral South Indian” (ASI) population that is not close to
    any large modern group outside the Indian subcontinent.

    Indeed, the Fst distances between components suggests that ANI/my Central South Asian (CSA) is basically Caucasoid, being about Fst=0.04 from the North European and West Asian components. The ASI/my South Indian (SIN) component is Fst=0.085 from Caucasoids and 0.101 from East Asians.

    Of course it’s likely that my SIN is not _exactly_ the same as ASI, as I don’t have as many Indian populations to work with, and my North Kannada speakers (who are my most “southern” population) may not be as “southern” as the tribals that Reich et al. had access to. Still it’s a good approximation.

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  • http://blogs.discovermagazine.com/gnxp Razib Khan

    page 40 of the supplements lays out the model which seems to comport with their results:

    - 4,000 gens ago Split of West African and Eurasian ancestors

    - 2,000 gens ago Split of ANI and ASI ancestors

    - 1,700 gens ago Split of Asian populations (‘proto-East Asia’, ASI, and Onge)

    your quote of reich is correct. my point is that they should be closer to ESA than any of the west eurasian groups, albeit it would be a close thing. ASI is clearly not a linear combination of west eurasians and east asians; it went on its own path. also, remember that the lowbound proportion of ANI is 40%, and highbound is 70%, by population. so the indians should be a little biased toward europeans, especially when considering that ANI is very close to west eurasians, while ASI is only closer to to ESA than west eurasians, not close.

  • Nasir

    Razib,

    Can you please elaborate on your comments on “Beharis”. Why are they lumped up with Arabs? Answer as if I am a 10 years old, plz :)

    A Bihari immigrant in the US.

  • http://blogs.discovermagazine.com/gnxp Razib Khan

    behar is a surname. he’s referring to a data set within a paper, where the first author had the name behar.

  • JLikens

    It’s interesting that whereas Finns have significant (~5-8%) NE Asian/Siberian ancestry, this component is negligible among Lithuanians. And yet a substantial proportion of the y-chromosomes of both groups belong to haplogroup N (the Finns obviously have more N, but not by a lot).

  • manju

    Can’t help noticing that purest ANI and purest ASI are both Dravidians.

  • http://washparkprophet.blogspot.com ohwilleke

    @JLikens

    The distinction between Finns and Lithuanians holds for mtDNA analysis as well. The people of the Baltics are more closely related genetically to the hunter-gatherer populations of pre-Neolithic Europe than the Finns once you get down to the specific hg sublineages.

  • http://washparkprophet.blogspot.com ohwilleke

    Expanding on Comment 8 per Helena Malmström et al., “Ancient DNA Reveals Lack of Continuity between Neolithic Hunter-Gatherers and Contemporary Scandinavians” via Dienekes:

    “Fst between the PWC and modern populations ranged between 0.036 (Latvians) and Saami (0.25). For Swedes and Norwegians they were 0.051 and 0.061.”

    PWC stands for Pitted Ware Culture, the last hunter-gatherer culture of Scandinavia before the food producing Funnel Beaker Culture (TRB) arrived. The PWC ancient DNA sample consisted of “19 PWC individuals “from three different sites on the Baltic island of Gotland dated to 4,800–4,000 years BP” which were found to belong to haplogroups J, T, V (one each), “Other” (two), U5 and U5a (three each), and U4/H1b (eight samples).”

  • JLikens

    Thanks Ohwilleke. That clarifies things somewhat.

    In your opinion, is the presence of haplogroup N within the populations of NE Europe unrelated to the Siberian/NE Asian admixture also found within (some of) those same populations?

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This blog is about evolution, genetics, genomics and their interstices. Please beware that comments are aggressively moderated. Uncivil or churlish comments will likely get you banned immediately, so make any contribution count!

About Razib Khan

I have degrees in biology and biochemistry, a passion for genetics, history, and philosophy, and shrimp is my favorite food. In relation to nationality I'm a American Northwesterner, in politics I'm a reactionary, and as for religion I have none (I'm an atheist). If you want to know more, see the links at http://www.razib.com

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