population expansion

Aimé C & Austerlitz F 2017 Different kinds of genetic markers permit inference of Paleolithic and Neolithic expansions in humans. Eur J Hum Genet 25:360-365.

• previous Paleolithic demographic expansions may have promoted the emergence of farming during the Neolithic period

• if two successive expansions occurred in the studied population, signals of the more ancient event might be masked by more recent signals and thus be undetectable

• using mitochondrial and autosomal DNA sequences, we detected expansion events predating the Neolithic transition in multiple African and Eurasian populations
• these results were consistent with previous genetic studies
• we detected signals of expansion events concomitant with the Neolithic transition in the same African and Eurasian populations using microsatellite data
• we also found expansion events concomitant with the Neolithic transition in Eurasia using Y0chromosome microsatellites
• these apparently contrasted results might be explained by two successive expansion events, one during the Palaeolithic and one during the Neolithic
• the results from the present simulation study demonstrate clearly that it is a plausible scenario
• the finding of a Paleolithic expansion event in Africa is consistent with some paleoanthropolofical data
• radiocarbon dating suggested a demographic expansion in Africa 60 000-80 000 YBP

• it will be interesting to analyze the efficiency of methods like MSMC¹² or PopsizeABC,³⁷ which assume a model in which populations go through successive events of instantaneous changes in population size through time
• these methods cannot assume a parametric model with for example one or two expansions with an exponential growth rate