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April 11, 2019

Tutsis are genetically very similar to Masai

Filed under: Human Population Genetics,Human Population Structure,Tutsi — Razib Khan @ 9:57 pm


Many years ago, before I used ggplot, I did a little analysis of the genetics of the Tutsi. Actually, it was the genetics of a single Tutsi, or more precisely, someone who was 75% Tutsi ancestry (3 out of 4 grandparents).

I found that the Tutsi individual seemed quite distinct from the Bantu peoples in nearby Kenya. I suggested that it was likely that the Tutsi were then genetically distinct from the Hutu people amongst whom they lived. For many years this was part of the genetics section of the Wikipedia entry on the Tutsi, but recently the reference was removed and the page seems to have been re-edited.

That’s fine. I’m just a random blogger who had one sample. But as it happened recently about a dozen Diasporic Tutsis reached out to me. Over the last decade, the number of people who have been genotyped has increased greatly. So it wasn’t that difficult for interested parties to find these genotypes.

The mission they put before me is simple: “tell us about our genetics”. Over the next few weeks, I’ll do that. As there is no IRB, this won’t be published in a peer-reviewed journal (I am open to putting any researcher in contact with these Tutsis who reached out to me). I’m just going to put what I find out there so that Tutsis who do personalized genetic testing can make sense of what they’re finding out.

I received these genotypes today. A quick merge of samples I have reduced it down to 50,000 markers. I will work on creating a merge with a larger number of markers. But, I’ll report what I have found out so far as a first pass.

As you can see on the PCA plot above the Tutsi overlap almost perfectly with the Masai. Not with the Kenyan Bantu, or the Luo, who are more “African” shifted. But with the Masai. But, they are not as “Eurasian shifted” as the Somali.

Treemix confirms this:

The Tutsi and Masai are right next to each other. Between the Somalis, and other Sub-Saharan Africans.

Running 5 migration edges, you see gene flow into the Tutsi from Cushitic populations.

I ran Admixture at K = 6. You can see the raw results, but the chart makes it clear, the Tutsi are like the Masai:

The same for K = 7:

I think that’s all for now. More later!

August 30, 2011

Tutsi genetics, ii

In my post below, Tutsi probably differ genetically from the Hutu, there were many comments. Some I did not post because they were rude, though they did ask valid questions. I will address those issues, but let me quote one comment:

That’s an interesting possibility, but this admixture run didn’t split the non-hunter-gatherer Africans that well. In one of your previous analyses on East Africa you managed to get a pretty accurate ‘Afro-Asiatic/Cushitic’ and ‘Nilotic’ cluster. Is it possible that you could run this Tutsi sample using the same admixture settings as in the ‘Flavors of Afro-Asiatic’ blog post to see if he carries a significant Nilotic component or is mainly Bantu & Cushitic derived?

So I replicated ADMIXTURE runs for many of the same populations as I did in my post, Flavors of Afro-Asiatic. I also pared down the population set and generated a PCA with EIGENSOFT. Before I get to those results, let me tackle the questions.

1) “Are the Luhya suitable proxies for the Hutus?”

Probably. The reason is that Bantu-speaking populations, from the Congo to South Africa, are surprisingly similar. Not only that, but these populations are very distinctive from groups which are close them ...

August 29, 2011

Tutsi probably differ genetically from the Hutu


Paul Kagame with Barack and Michelle Obama

I first heard about Rwanda in the 1980s in relation to Dian Fossey’s work with mountain gorillas. The details around this were tragic enough, but obviously what happened in 1994 washed away the events dramatized in Gorillas in the Mist in terms of their scale and magnitude. That period was a time when the idea of “ancient hatreds” leading to internecine conflict was in the air. It was highlighted by the series of wars in the former Yugoslavia, and the Tutsi-Hutu civil wars in Rwanda, Burundi, and Congo. Of the latter the events in 1994 in Rwanda were only the most prominent and well known.

After having read Dancing in the Glory of Monsters: The Collapse of the Congo and the Great War of Africa I am relatively conscious of the broader canvas of what occurred in Central and East Africa in the 1990s. Not only was there a conflict between Tutsi and Hutu in Rwanda, but a similar dynamic also flared up in Burundi. The tensions are more complex in Congo and Uganda, in large ...

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