Did Our Species Evolve in Subdivided Populations across Africa, and Why Does It Matter?

“…60 ka. This observation is consistent with recent proposals that the cultural and biological evolution of H. sapiens in Africa occurred as a mosaic of local developments ( 26 ).…”

“…The overall morphological pattern in MSA North African faces suggests there was both regional continuity from the Early to Late Stone Age, as well as gene flow between H. sapiens groups living in other parts of Africa and the southwest Asia (Bergmann et al, 2022;Ferembach, 1976aFerembach, , 1976bHarvati & Hublin, 2012;Röding et al, 2022). These findings are consistent with the view that our species originated and diversified within subdivided populations that were connected by intermittent gene flow (Scerri et al, 2018;Stringer, 2016). The shared maxillary shape in MSA humans across Africa and the southwest Asia is likely a result of such gene flow.…”

“…Nonetheless, the fact that our modeled relationship between ecology and CAHG presence is consistent with the location of past archaeological assemblages and human remains suggests that as well as having remained genetically distinct for a very long time, contemporary African hunter-gatherers occupy similar habitats to their ancestors. It also supports recent morphological and genetic evidence that early hunter-gatherer populations in Africa were highly structured into semi- rather than fully-isolated groups ( 1 , 9 , 23 , 42 ). This form of sociality characterized by a combination of local differentiation and partial connectivity, facilitated by the fluid structure of hunter-gatherer bands, may also explain the ability of early hunter-gatherer groups to maintain relatively large and stable effective population sizes ( 47 – 49 ) despite regular episodes of environmental fragmentation.…”