Modelling the spread of farming in the Bantu-speaking regions of Africa: an archaeology-based phylogeography.
We use archaeological data and spatial methods to reconstruct the dispersal of farming into areas of sub-Saharan Africa now occupied by Bantu language speakers, and introduce a new large-scale radiocarbon database and a new suite of spatial modelling techniques. We also introduce a method of estimating phylogeographic relationships from archaeologically-modelled dispersal maps, with results produced in a format that enables comparison with linguistic and genetic phylogenies. Several hypotheses are explored. The 'deep split' hypothesis suggests that an early-branching eastern Bantu stream spread around the northern boundary of the equatorial rainforest, but recent linguistic and genetic work tends not to support this. An alternative riverine/littoral hypothesis suggests that rivers and coastlines facilitated the migration of the first farmers/horticulturalists, with some extending this to include rivers through the rainforest as conduits to East Africa. More recently, research has shown that a grassland corridor opened through the rainforest at around 3000-2500 BP, and the possible effect of this on migrating populations is also explored. Our results indicate that rivers and coasts were important dispersal corridors, but do not resolve the debate about a 'Deep Split'. Future work should focus on improving the size, quality and geographical coverage of the archaeological (14)C database; on augmenting the information base to establish descent relationships between archaeological sites and regions based on shared material cultural traits; and on refining the associated physical geographical reconstructions of changing land cover.
School of Geography, Archaeology and Environmental Studies, University of the Witwatersrand, Johannesburg, South Africa.
Thembi
T
Russell
Institute of Archaeology, University College London, London, United Kingdom ; School of Archaeology, History and Anthropology, University of Wales Trinity Saint David, Lampeter, United Kingdom.
Fabio
F
Silva
School of Geography, Archaeology and Environmental Studies, University of the Witwatersrand, Johannesburg, South Africa ; Institute of Archaeology, University College London, London, United Kingdom.
James
J
Steele
D017954:Africa South of the Sahara; D000383:Agriculture / Q000266:history*; D001106:Archaeology; D044383:Black People; D005580:Fossils; D049690:History, Ancient; D006801:Humans; D008962:Models, Theoretical; D058974:Phylogeography