Population regime· The columns of time
Scattered foragers
350 ka → 65 ka
Small, scattered foraging populations, in Africa first and, for a very long time, almost nowhere else.
What the evidence shows
For most of the time this band covers, the whole species is a scatter of small groups on one continent, and genetics can say something surprising about how few of them there were. Reconstructions of effective population size, the number of breeding individuals a modern genome implies, stay in the thousands to tens of thousands across these 285,000 years. Effective size is not a head count and is usually far below it, but the order of magnitude is the point: for nine tenths of our history the species was one scarce African mammal among others.
Bounds and conventions
No census is possible at this depth. Genetic data trace only relative changes in effective population size, never head counts, so the absolute numbers stay unknown.
Sources
- McEvoy, B. P., Powell, J. E., Goddard, M. E., Visscher, P. M. (2011). Human population dispersal "Out of Africa" estimated from linkage disequilibrium and allele frequencies of SNPs. Genome Research 21(6), 821–829.
- Hublin, J.-J., Ben-Ncer, A., Bailey, S. E., et al. (2017). New fossils from Jebel Irhoud, Morocco and the pan-African origin of Homo sapiens. Nature 546, 289–292.