Explainer

ADMIXTURE

Do note that the admixture components do not necessarily represent real ancestral populations. Also, the names I have chosen for the components should be thought of as mnemonics to ease discussion. I chose them based on which modern populations in my data these components peaked in. They do not tell anything directly about ancestral/ancient populations. The best way to look at these admixture results is by comparing individuals and populations.

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24 Comments.

  1. Hi Zack

    Apologies if it's somewhere and I missed it, but how do you create the interactive barcharts for structure/admixture results?

  2. Hi Zack,

    I was just overlooking my Admixture results that you posted (tanks, btw!), and i'm wondering about the American classification. Is there something that can be found in DNA that is specific to Americans? It has been a long time since i took biology and i am guessing i missed something since then. Thanks again

  3. Okay, that makes perfect sense. Thanks again.

  4. Zack,

    Two questions, which I think belong in the explainer.
    a) Read thru most of your early posts and the earliest post where K=11 and you have S Asian and Onge components is the post on April 21 2011. I understand the concept of forcing the data into 11 components. What I dont get is how those components are equated to S. Asian, Onge etc.

    Does
    1)ADMIXTURE have the Reference SNP's equating to pure S. Asian Onge etc
    2)or do you create reference SNP's equating to pure S. Asian Onge and use those when you do the analysis in ADMIXTURE.

    b) I am trying to understand the relationship between the Fst Dendogram and Reich et al, phylogenic tree. I see that you say "Just remember it's not a phylogeny". Saw one comment " Would the statement "C1 S. Asian and C4 SW Asian may be similar to the AN1+ASI of Reich et al" be correct. Would that be correct. I am sure this has been asked before, please direct me to that post.

    • Don't think of the ancestral components, like South Asian, Onge etc, as pure ancestral allele frequencies. The names of the components are just mnemonics to make it easy to remember and discuss. These labels are based on which present populations that component peaks in.

      The components are computed by ADMIXTURE using a maximum likelihood algorithm. These allele frequencies do not, in general, represent any populations in the distant past. The best way to think of admixture results is in comparison with others, both the reference populations and project participants.

      • Thanks.

        Just dropped my 23andme sample at the Jersey City USPS (In NYC at the moment). So in about six weeks or so you will have another Sri Lankan participant.

      • Thanks for the explanation.
        Just dropped my 23andme sample at Jersey City USPS (I live in NYC). So in about 6 weeks should have another Sri Lankan participant.

        Sorry if you have had many of the same. Seems like my comments dont show up.

  5. Thanks for the explanation. Its starting to make sense now.
    Just dropped the 23andme sample at Jersey City USPS (I am in NYC). So hopefully in six week you will have another Sri Lankan participant.

  6. Hi,
    Am I correct in understanding that:
    S-Indian= South American Native American
    Caucasian=caucasus region
    San=southern Japan?

  7. What group of people does San reference?

  8. Hi Zack,
    Just have a query regarding the "American" component of the test. I am half Punjabi and half Trinidadian (Indian, Scottish and Portuguese). The results from Harappa World showed up my Asian ancestry as well as the expected European ancestry however also showed up 0.67% American. My question is whether this could be real Amerindian DNA (as there are Amerindians in Trinidad) or whether people who are mainly South Asian would show any similar American DNA?
    Hope you can clear this up. Thanks,
    Kyle

  9. Hi Mr Zack,
    I did dna tests and I coudn't understand something.How can I find my paternal and maternal ancestry?I have a kit number from 23andme.My kit number is m343300.I know my mother's ancestry,they said to me,They are Armenian but father's side I dont know.I asked my paternal side,they dont know anything about their ancestry.Can you help me please?Thank you.

    Best Regards

  10. I was told that Harrappa Gedmatch and K9 or 7 ? and other calculation formulas were on hand to calculate by some other way the distribution of a Genome. I am really a beginner and would like to know where all that is available online?
    Somebody can help me?
    Thanks

  11. So does this study conclude south asians are a racially admixed population with negritid,caucasoid and mongloid elements. Like the average indian looks 75 percent caucasoid 5 percent mongloid and 20 percent negritid and is close to that genetically

  12. Hello,
    I was wondering if the onge component is actually the component from andaman islanders? I can actually believe that most indians do range from 10-50 percent onge the ones that come to america are like around 10-20 and are like north indians and south indian brahmins are like 15-25 percent so i think thats why many people equate indians to not have features between andaman islanders. Also if you go to india you will see many indians in fact to look like an intermediate of onge and mediteranean european as they have wavy to curly hair which is in between straight and nappy and also have a medium nose in between thin and broad. Also the skin color ranges from white to black. South asians do look mixed. I would say average north indian is 65caucasoid-35 percent onge (australoid) and south indians approach 60 percent onge-40 percent caucasoid. But keep in mind some north indians can have more onge(australoid) than south indians. This is just a general average.
    This pca i put link on website shows how south asians cluster between australoids and caucasoids.

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