View Full Version : IBD Sharing in the Horn

02-07-2018, 02:52 AM
Has anyone seen any data on IBD sharing amongst East African groups? I know that Dodecad looked at this back in 2012, but not sure if more has been learned since then. Obviously neighbors share dna, but I have been surprised at how random matches between neighbors can be (>10cm). Somali and Ethiopians for example are neighbors, but from what I have seen the few gedmatch samples, there are very few IBD matches between the two. Conversely, I have seen matches from Ethiopians/Eritreans in the far north share IBD with adoptees in the far southern regions of Ethiopia and Sudanese/Egyptians outside of the country.

I guess if a group stays isolated for a few hundred years, smaller segments can drop off. Please share any insights.

02-07-2018, 03:52 AM
Well it makes total sense considering Habeshas and Somalis don't share a border and have never encountered one another.Also I think you are forgetting "Ethiopian" isn't an ethnic group but rather a nationality of many different ethnic groups including many Somalis.

That being said I do believe that if a lot more Eastern Oromos and Djoubitian/Ethiopian Afars were tested they would definently share common segments.Heck I personally have a half Oromo uncle back home in Somaliland (his mother is from Wellega) and there are many Oromized Somali clans and vice versa on our western borders.

02-07-2018, 05:51 AM
Shewa sits center to the ancient Adal trading route that included Afar and Harrari at times. Sure, those who boarder the area will share more dna. My point is that there may be more than geography at play when considering IBD sharing levels, especially between geographically close groups. I am thinking namely culture and to some degree religion may be significant factors. For example, some of these groups are more patriarchal and endogamous than others. We saw this play out in the Lacovacci STR analysis where both Somali and Saho samples were extremely bottlenecked, as an example. Anyway, more samples will clarify.

02-08-2018, 02:10 PM
ethnic Somalis are generally very different from other Horners, despite the same origins (Cushitic) they have been more isolated from the others in the past 3,000 years. Somalis from the far Eastern parts even more so than those from Ethiopia.