Linguistic and genetic perspectives on Central African history

  • Date: –17:00
  • Location: Engelska parken 22-0031
  • Lecturer: Tom Güldemann Gwenna Breton
  • Contact person: Harald Hammarström
  • Seminarium

The prehistory of the Central African rainforest continues to be an enigmatic research area, in particular as it pertains to the so-called Pygmy forager populations who are universally assumed to have undergone a complete shift to the languages of their farming neighbors.

Speaker: Tom Güldemann (Humboldt U, Berlin, joint work with B. Winkhart)
Title: From local Pygmy to wider Central African history: *Baakaa forager, Ubangi and Bantu peoples in the western part of the rainforest
Abstract: The prehistory of the Central African rainforest continues to be an enigmatic research area, in particular as it pertains to the so-called Pygmy forager populations who are universally assumed to have undergone a complete shift to the languages of their farming neighbors. The situation of the two largest "Western Pygmy" populations, Baka and (Y)aka, found on both sides of the Sangha River, is particularly enigmatic. On the one hand, they speak very different languages, the former from the Mundu-Baka (Ubangi) family and the latter from the Bantu (Benue-Kwa) family. On the other hand, they share a historically diagnostic body of linguistic and other cultural features, which has led to the quite plausible conclusion that the two groups once formed a single ancestral population called *Baakaa (Bahuchet e.g., 1992, 1993). The currently avalaible historical explanation for this modern picture has been intimately intertwined with a far more general but poorly substantiated population modeling proposed by Bouquiaux and Thomas (1980) for the entire north of the Central African rainforest. Our recent reassessment of the forager-farmer interaction pertaining to the *Baakaa complex, based on both old and new data, turns out to not only concern local population history along the Sangha River but has repercussions for hypotheses about the past of the entire rainforest, offering, in particular, a different perspective on the interaction between Bantu and non-Bantu populations, both foraging and food-producing, and thus the geographical conceptualization of the Bantu expansion into and within the rainforest as a whole.

Bahuchet, S. 1992. Histoire d'une civilisation forestière I: dans la forêt d'Afrique centrale; les Pygmées Aka et Baka. Leuven/ Paris: Peeters.

Bahuchet, S. 1993. Histoire d'une civilisation forestière II: la rencontre des agriculteurs - les pygmées parmi les peuples d'Afrique centrale. Leuven/ Paris: Peeters.

Bouquiaux, L. and J. M. C. Thomas. 1980. Le peuplement oubanguien. In Bouquiaux, L. (ed.), L'expansion bantoue. Paris: SELAF, vol. 3: 807-822.

Güldemann, Tom and Benedikt Winkhart. 2020. The *Baakaa and other puzzles: forager, Ubangi and Bantu peoples in the western Central African Rainforest. submitted to Anthropological Linguistics.

 

 


Speaker: Gwenna Breton (Uppsala U, joint work with Sjödin, P., Zervakis, P.I., L
Title: Deciphering early human history using Approximate Bayesian Computation and whole genomes from Central and Southern Africa.
aurent, R., Sjöstrand, A.E., Hewlett, B.S., Barreiro, L.B., Perry, G.H., Soodyall, H., Heyer, E., Schlebusch, C.M., Verdu, P., Jakobsson, M.)
Abstract: Human evolutionary history in Africa before and after the out-of-Africa event remains largely unexplored, due to lack of genome sequence data, limited representation of populations and limitations of presently available inference methods. We generated high-coverage genomes from from five rainforest hunter-gatherer populations and four neighbouring populations from Central Africa, and from five Khoe-San populations from Southern Africa. We analysed these genomes jointly with comparative genomes from worldwide populations. We showed that rainforest hunter-gatherers and Khoe-San populations define two distinct major axes of genetic variation both at the worldwide and Sub-Saharan scales. This new data provides unprecedented resolution to unravel complex genetic differentiation among rainforest hunter-gatherer populations in particular. For example, the Baka and Aka individuals, who are geographically distant and speak languages from different language families, are genetically similar. Using both deterministic and Approximate Bayesian Computation inferences, we found strong support for gene flow throughout the entire history of Central and Southern Africa, and an early divergence, some 250-370 kya, of Khoe-San ancestors from the lineage ancestral to all Central African populations. This event was followed, still in the presence of gene-flow, by the divergence of lineages ancestral to rainforest hunter-gatherers and their neighbours. Finally, divergence between the different Khoe-San populations likely predated that of eastern and western rainforest hunter-gatherers which occurred 16-44 kya. Altogether, our results indicate that a tree-like history of Central Africa incorporating gene-flow among ancient lineages as well as among recent lineages can explain genomic variation observed among populations today.