Quick question about the Beja

[Ryukendo]

If you look at the analysis of Gopalan et. al. (2019) you can see that the Hadendowa Beja have almost 25% "Nilotic" ancestry. 3 quick questions:

1. Is this also the case among other Beja?
2. How did this come about? Do we know/think that this is ancient, rather than a result of the slave trade?
3. What do we know about the ethnohistory of the Beja? Did they expand from south up North (doesn't seem to be the case, what with their conquests of Sudan and so on) or from the north down South? If from the North, how did this Cushitic-speaking group end up in the Eastern desert right beside former Egyptian-speakers?

Edit: I see that people connect through onomastic evidence the speech of Northern Nubians such as the Blemmnyes with the languages of the present-day Beja, explaining how they could have ended up so far north.
Follow-up question: this is interesting, because the Beja seem to be repeatedly placed in a basal position in classifications of Cushitic languages, or at least South Cushitic is repeatedly placed as being deeply nested within a clade containing most other Cushitic languages, where Beja is not. Since we have genomes from the Pastoral Neolithic (PN) associated with Southern Cushitic speakers which are something like Natufian+Dinka+Mota, but the only HG element in the Beja looks like Dinka, plus the fact that the admixture with the two different HG groups seems to have occurred through a two-step process via admixture dating, this seems to suggest a stage of acquisition of Ethiopian HG ancestry (Mota) with the spread of the Cushites south through the Horn, with the distribution of proto-Cushites ultimately extremely far to the north without contact with HGs of Ethiopia, would you agree?

[Ryukendo]

Lank has discussed his views here. The picture he paints seems quite coherent.

The entire discussion is super interesting, wish I had come across it earlier!

[Awale]

If you look at the analysis of Gopalan et. al. (2019) you can see that the Hadendowa Beja have almost 25% "Nilotic" ancestry.

Well, they technically have much more than that. Nilotic-like ancestry in these guys seems on level with the Nilotic-like + Mota-related ancestry in Tigrinyas (~50%) based on where they cluster:

 

But yes, they seem to have about 25% or so outside of what basically looks like a repeat of the typical Ethio-Somali cluster which seems to contain most of the rest.

1. Is this also the case among other Beja?

Seems so. The Beni-Amer are a Beja tribe and their results don't seem that different in the paper. The Beni-Amer are more like a Horner-admixed Beja tribe that tends to sometimes speak Tigre (Ethiosemitized) though but yeah.

2. How did this come about? Do we know/think that this is ancient, rather than a result of the slave trade?

Part of it probably has the same source as the excess "Nilotic" in Horners outside of Ethio-Somali whereas a notable amount of it is probably real admixture from Eastern-Sudanic speakers. Bejas seem affected by the same admixture events as Sudani-Arabs and Nubians. Eastern-Sudanic speakers carrying Yoruba-like ancestry, historic period Egyptian admixture and probably real Arabian ancestry given many Sudanese J1 subclades basically being Arabian from what I hear. I doubt any of it has much to do with the slave-trade. You can see what I mean when you observe Beja and other north Sudanese groups' uniparental lineages where, for example, Bejas have the same African (xM&N) skew as other north Sudanese groups in terms of mtDNA lineages (though to a lesser degree). A skew Horners don't share. In fact, Horner mtDNA frequencies interestingly tend to sync closely with Horners' African:Eurasian scores using formal-stats like Somalis appearing 38-40% Eurasian in formal-stats and showing a frequency of about 38-40% for M&N lineages and Tigrinyas being pretty much 50:50 in terms of both auDNA according to formal-stats and mtDNA frequencies.

3. What do we know about the ethnohistory of the Beja? Did they expand from south up North (doesn't seem to be the case, what with their conquests of Sudan and so on) or from the north down South? If from the North, how did this Cushitic-speaking group end up in the Eastern desert right beside former Egyptian-speakers?

They are, linguistically speaking at least, the successors of the Cushitic speakers who stayed behind in the areas north of the Horn. I did some decent reading on this a couple of years back and Agamemnon shared some sources and rundowns himself in private that I now don't have on me (hopefully he does and sees this thread) but the fact that they seemingly remained in the general area of Southern Egypt and Northern Sudan whereas other Cushites went south is pretty clear linguistically speaking.

Now linguistic issues are solved through linguistics first and foremost but if you want to look at some of the genetics for some hints too then there's also the fact that the Hadedowa don't seem to show any Mota-related ancestry unlike all Horners in that study's ADMIXTURE run. The Beni-Amer show some but this can be explained by their being Horner admixed compared to other Beja tribes. This pretty much implies these guys' ancestors were likely never in the Horn.

Follow-up question: this is interesting, because the Beja seem to be repeatedly placed in a basal position in classifications of Cushitic languages, or at least South Cushitic is repeatedly placed as being deeply nested within a clade containing most other Cushitic languages, where Beja is not. Since we have genomes from the Pastoral Neolithic (PN) associated with Southern Cushitic speakers which are something like Natufian+Dinka+Mota, but the only HG element in the Beja looks like Dinka, plus the fact that the admixture with the two different HG groups seems to have occurred through a two-step process via admixture dating, this seems to suggest a stage of acquisition of Ethiopian HG ancestry (Mota) with the spread of the Cushites south through the Horn, with the distribution of proto-Cushites ultimately extremely far to the north without contact with HGs of Ethiopia, would you agree?

Beja is the most "basal" Cushitic branch. Then you have Proto-Agaw-East-South Cushitic then Agaw cuts off and East-South remain together for a time and split as well. East & South are very close. I recall some linguists even trying to argue that South-Cushitic is basically just a subbranch of East-Cushitic.

 

this seems to suggest a stage of acquisition of Ethiopian HG ancestry (Mota) with the spread of the Cushites south through the Horn, with the distribution of proto-Cushites ultimately extremely far to the north without contact with HGs of Ethiopia, would you agree?

Yes. Though I wouldn't say "extremely" far to the north but definitely north of the Horn.

[Granary]

According to our best guesses when did Beja split from the other Cushitic languages?

[Awale]

According to our best guesses when did Beja split from the other Cushitic languages?

Beja or "North-Cushitic" seems to have split by at least 8,500ybp (6500 BCE):

The evidence that Proto-sahelian borrowed its words for “goat” from an already distinct ancestral beja language in the later seventh millennium6 supports the conclusion that the initial divergence of Proto-Cushitic into the Beja (North Cushitic) branch and Agäw-East-South-Cushitic branches began before 6500 BCE - History and the Testimony of Language by Christopher Ehret

And you start seeing evidence of pastoralists across areas south of what is now Eritrea like the Ethiopian Highlands and northern Somali territory (see also here) by at least 5,000ybp (3000 BCE) based on the large array of rock-art depicting things like humpless cattle (not Zebu admixed), goats, sheep and people who keep these animals and also practice some hunting. These people are, from what I gather, also the source of the rock-carving, stelae raising, burial mound and cairn raising traditions of the Horn found among Cushites and Ethiosemites until relatively recently.

The so far proposed Proto-Cushitic Urheimat more or less aligns with the historical spread of the Beja people as well:

 

[Atlas]

So, do most Somalis actually have some trace of West African-like ancestry as shown in page 16 of the study by Gopalan et. al.? I wasn't aware this was present in Somalis, or does it represent something else? It seems strange that it's at higher levels in Somalis than in all the other Horner groups, too. I wonder if this may tie in with what I've seen of some results from the 23andMe subreddit where some southern Somalis occasionally have trace amounts of (<1%) Southeast African, which is interesting, but perhaps not wholly unexpected.