Comments on: Any Tutsi genotypes around?

By: Eze

Eze — Sun, 03 Jul 2011 22:57:29 +0000

There are some Rwandan STR genotypes from Tishkoff et al. (2009) available. However, the samples consist of people with mixed Hutu and Tutsi ancestry. I pulled down this data and decided to run a structure analysis on them, using some regional divergent contact groups, such as the Sandawe, Mbuti (Pygmy), Igbo (proto-Bantu), Dinka (Nilotic), Borana (Cushitic), this was the outcome:

http://img835.imageshack.us/img835/5041/structure.png

The Rwandan samples were quite heterogeneous. Two samples show little to no non-Bantu ancestry, and then you have three samples showing significant Nilotic influence, and the remainder showing significant Cushitic admixture (max was 50%, possibly a mostly Tutsi sample?). Pygmy ancestry was pretty much absent.

By: Lank

Lank — Sun, 03 Jul 2011 20:22:05 +0000

I’m glad you got my point; all I ask for is consistency. Bantu peoples are diverse, and we must not forget that it really is just a linguistic classification, although we should also be able to discuss the inferred “Bantu” ancestral component. But then we should also be very clear about what we’re discussing, IMHO.

Regardless of how the Tutsis turn out genetically, I can assure you that you would find people who are similar to them genetically in Kenya, a place where the genetic affinities of different Bantu-speaking groups range from simply “Bantu” to “Bantu-Nilotic”, “Bantu-Cushitic” and everything in between. Yet, no one would suggest that these Bantu Kenyans, or the many “mixed” Bantus around Africa, aren’t Bantus.

If there’s anything that unites Bantus other than the shared language and West/Central African ancestry, it is the fact that Bantus are also generally mixed with the local people from their respective regions.

I got the analogy by the way, you learn a lot through following these ancestry projects.

By: Razib Khan

Razib Khan — Sun, 03 Jul 2011 19:52:59 +0000

By the way, Tutsis and Hutus speak the same language today, so they are both classified as Bantu.

so the twa, hutu, and tutsi are all bantu because they speak the same language?* point taken, but the tutsi seem as bantu as tamil brahmins are dravidian (south indians will understand the analogy).

in any case, i’m hoping that someone of 23andme’s 100,000 customers is part of the tutsi diaspora in the west. and N = 1 would be more useful than N = 0.

* in fact, some pygmies are bantu, and some sudanic, then. so on the boundary the language classifier removes important information.

By: Lank

Lank — Sun, 03 Jul 2011 19:25:33 +0000

I’m afraid you would have a hard time finding any autosomal (SNP-based) Tutsi data. Their genetic affinities will probably remain a mystery for at least a while longer. Tishkoff et al. (2009) did include some mixed “Tutsi/Hutu” samples, but the sample size was low and you would not be able to use them in the AAP. In Tishkoff’s study, some of the samples were more Cushitic than Nilotic, whereas others had more Nilotic influence.

By the way, Tutsis and Hutus speak the same language today, so they are both classified as Bantu.