[Discussion] Chronology of the Bantu expansion

[Granary]

Hello, I wanted to create this thread to discuss the linguistic, genetic and archeological evidence for a general chronological-spatial model for the Bantu expansion so we can properly answer when Bantus arrived at any given region and why we believe that.

A couple of leading questions/facts I know:

-Do the Shum Laka samples meaningfully change our understanding of the Bantu expansion? I ask this about the late 2nd millennium BCE samples, if the Bantu expansion was already underway why would a place so near their homeland of all places have such a different population? Or is it simply just a isolated pigmy enclave?

-We have evidence of continuity in Malawi in Fingira up to around 500 BCE but we also have evidence of mostly Bantu individual in Botswana around 600 CE, I guess a non-Bantu sample is not necessarily evidence of Bantu absence but the presence of a single Bantu does prove to some extent the existence of Bantus, the extent though I guess is debatable.

-In terms of very early written evidence, when can we put a latest date for East Africa?

[Granary]

Some resources I found:

https://core.ac.uk/download/pdf/157573257.pdf

And maps that shouldn't contradict what is said in the file above:

[NetNomad]

http://yfull.com/tree/E-M2

When E-M2 lineages stop being West African and start becoming Central or Southeast African (and Arabian via the Indian Ocean slave trade) is mostly around 4-2 kyBP.

[Granary]

http://yfull.com/tree/E-M2

When E-M2 lineages stop being West African and start becoming Central or Southeast African (and Arabian via the Indian Ocean slave trade) is mostly around 4-2 kyBP.

That's in line with the evidence, although I think the Bantu expansion beyond the rainforest can't be dated prior to 1000 BCE given what we have now, the evidence there agrees for Bantus coming in the Great Lakes region around 600 BCE(Urewe tradition).

BTW about East Africa, do you have any idea of what happened there to the Cushitic population in Western Kenya and Tanzania? Did they leave any noticeable linguistic and genetic trace in the modern populations? I know of the Iraqw but I was wondering how much of a Cushitic substratum there was and what it could tell us of how widespread Cushites were prior.

[ThaYamamoto]

I like tha idea of this thread bro, right now I don't have any sources etc so these are some observations off the dome. The map in the first image is actually great. I don't think the Bantu homeland is in Nigerian Calabar/NW Cameroon and probably wasn't the dispersal point. I say this cuz Blench believes on linguistic and archaeological grounds, the Bantu may have originated/expanded from the Adamawa plateau, which is more North/Central-East than it is extreme South-East like has been suggested by some others. Ekoid/Enjagham are still spoken in Nigeria particularly in the South-East as well as Cameroon, so that lends support to them originating/expanding from there, but we have Jarawan peoples who speak a language closer to the narrow Bantu cluster [far as I remember I don't got sources rn] still in Nigeria to this day, but apparently linguists ignore this fact to make their explanations more parsimonious.

I'm inclined to the think that the Bantu homeland is much further West as can be seen by the genetic signature even in Ghana (unsupervised of course) - think Razib had them at 40% 'Bantu' in that old unsupervised run of his. When you start allocating clusters things change but I'd reckon Nigerian Delta maybe as the source of the proto-proto-Bantu peoples. Maybe. Again I'm just going off the top here. The Ijaw, with their most isolated/drifted language within Niger-Congo deep in Southern Nigeria, I think would definitely shed light on some things. I say this cuz I came across an Ijaw's ancestry results on Fonte Felipe's blog and surprisingly he/she scored the highest 'Cameroon/Congo/Southern Bantu' than any other Nigerian pop in his database...which is funny considering Efiks are far closer to Cameroon/Bantu peoples today, and don't exhibit as much as that individual. But its one sample, unfortunately. With Ijaws' massive [language] drift and isolation though I've been thinking they are prolly a major key.

That's in line with the evidence, although I think the Bantu expansion beyond the rainforest can't be dated prior to 1000 BCE given what we have now, the evidence there agrees for Bantus coming in the Great Lakes region around 600 BCE(Urewe tradition).

BTW about East Africa, do you have any idea of what happened there to the Cushitic population in Western Kenya and Tanzania? Did they leave any noticeable linguistic and genetic trace in the modern populations? I know of the Iraqw but I was wondering how much of a Cushitic substratum there was and what it could tell us of how widespread Cushites were prior.

In regards to Tanzanians in particular (I'm not gonna get into Kenya etc its messy and I can't really explain Kikuyus etc as well as someone else), you can see in the attached admixture [a pretty nuanced run where they allowed for both supervised and unsupervised after a certain K, shout out to them] that the Tanzanian/Nyamwezi groups like Sukuma, Gogo etc have a significant cushitic/pastoralist and eastafrican hunter gatherer input. You can find tha study here

[ThaYamamoto]

I'm starting to think that Proto-Potou-Tano-Bantu/Proto-Potou-Akanic-Bantu is actually just an even mix of Bangime + Mota, amateur as it sounds. That's why the signal is strong all the way into Ghana (30-40%?). But that wouldn't explain the prevalence of L3b etc on the Atlantic Coast. What yall think?

[Granary]

I like tha idea of this thread bro, right now I don't have any sources etc so these are some observations off the dome. The map in the first image is actually great. I don't think the Bantu homeland is in Nigerian Calabar/NW Cameroon and probably wasn't the dispersal point. I say this cuz Blench believes on linguistic and archaeological grounds, the Bantu may have originated/expanded from the Adamawa plateau, which is more North/Central-East than it is extreme South-East like has been suggested by some others. Ekoid/Enjagham are still spoken in Nigeria particularly in the South-East as well as Cameroon, so that lends support to them originating/expanding from there, but we have Jarawan peoples who speak a language closer to the narrow Bantu cluster [far as I remember I don't got sources rn] still in Nigeria to this day, but apparently linguists ignore this fact to make their explanations more parsimonious.

I believe we should always distinguish between narrow and Bantoid languages, for narrow Bantu langauges the homeland or last place where the population was close must be in Cameroon, the modern linguistic situation is just too in line with that idea.

I can't properly comment on Bantoid, I don't even really know the chronological depth of the branch itself. Even there though I believe the Bantoid branch homeland is East of the Niger, as even Benue-Congo is today concentrated east of there.

I'm inclined to the think that the Bantu homeland is much further West as can be seen by the genetic signature even in Ghana (unsupervised of course) - think Razib had them at 40% 'Bantu' in that old unsupervised run of his. When you start allocating clusters things change but I'd reckon Nigerian Delta maybe as the source of the proto-proto-Bantu peoples. Maybe. Again I'm just going off the top here. The Ijaw, with their most isolated/drifted language within Niger-Congo deep in Southern Nigeria, I think would definitely shed light on some things. I say this cuz I came across an Ijaw's ancestry results on Fonte Felipe's blog and surprisingly he/she scored the highest 'Cameroon/Congo/Southern Bantu' than any other Nigerian pop in his database...which is funny considering Efiks are far closer to Cameroon/Bantu peoples today, and don't exhibit as much as that individual. But its one sample, unfortunately. With Ijaws' massive [language] drift and isolation though I've been thinking they are prolly a major key.

How old is "Volta-Congo"? In any case aren't such genetic patterns just indicative that West Africans and Bantus have recent common origins? This wouldn't be surprising so I'm not sure how much it says about the Bantu homeland.

In regards to Tanzanians in particular (I'm not gonna get into Kenya etc its messy and I can't really explain Kikuyus etc as well as someone else), you can see in the attached admixture [a pretty nuanced run where they allowed for both supervised and unsupervised after a certain K, shout out to them] that the Tanzanian/Nyamwezi groups like Sukuma, Gogo etc have a significant cushitic/pastoralist and eastafrican hunter gatherer input. You can find tha study here

Ngl it's hard for me to read those graphs, I wish they had them in a numerical format.


In any case in terms of linguistic replacement in Nigeria is there a particular region that is today Benue-Congo that was not in the "recent" past(last 3 millennia) or vice versa? Because if the modern situation is roughly the same as it was 2-4 millennia ago then Benue-Congo must have originated also near Cameroon even if within Nigeria.

[Granary]

I'm starting to think that Proto-Potou-Tano-Bantu/Proto-Potou-Akanic-Bantu is actually just an even mix of Bangime + Mota, amateur as it sounds. That's why the signal is strong all the way into Ghana (30-40%?). But that wouldn't explain the prevalence of L3b etc on the Atlantic Coast. What yall think?

I'm not familiar with this linguistic branch, is it more solid than the general Volta-Congo branch?

[Brwn_trd]

Hello, I wanted to create this thread to discuss the linguistic, genetic and archeological evidence for a general chronological-spatial model for the Bantu expansion so we can properly answer when Bantus arrived at any given region and why we believe that.

A couple of leading questions/facts I know:

-Do the Shum Laka samples meaningfully change our understanding of the Bantu expansion? I ask this about the late 2nd millennium BCE samples, if the Bantu expansion was already underway why would a place so near their homeland of all places have such a different population? Or is it simply just a isolated pigmy enclave?

-We have evidence of continuity in Malawi in Fingira up to around 500 BCE but we also have evidence of mostly Bantu individual in Botswana around 600 CE, I guess a non-Bantu sample is not necessarily evidence of Bantu absence but the presence of a single Bantu does prove to some extent the existence of Bantus, the extent though I guess is debatable.

-In terms of very early written evidence, when can we put a latest date for East Africa?

There was no agenda to eliminate hunter gatherer populations which existed alongside agricultural populations. There are several regions where stone using populations were attested even up to the 17th century in Ghana. The point is, the presence of one population does not mean the absence of the other, therefore the Shum Laka samples should not be over intepreted.

Some models of the bantu expansion have a natural expansion after the adoption of a stable economic system. The faster population growth would result in assimilation of populations with less stable economic systems with minimal impact on the genome. In regions where the economic systems result in similar population dynamics, stable boundaries formed from which bidirectional assimilation occurred. In such regions, there was significant impact on the genome of bantu populations. Malawi is of the first type, and botswana of the second.

[ThaYamamoto]

There was no agenda to eliminate hunter gatherer populations which existed alongside agricultural populations. There are several regions where stone using populations were attested even up to the 17th century in Ghana. The point is, the presence of one population does not mean the absence of the other, therefore the Shum Laka samples should not be over intepreted.

Some models of the bantu expansion have a natural expansion after the adoption of a stable economic system. The faster population growth would result in assimilation of populations with less stable economic systems with minimal impact on the genome. In regions where the economic systems result in similar population dynamics, stable boundaries formed from which bidirectional assimilation occurred. In such regions, there was significant impact on the genome of bantu populations. Malawi is of the first type, and botswana of the second.

Can you tell us more about these types in Ghana? Fascinating