The Toba catastrophe theory , which postulates a population bottleneck for '' H. sapiens '' about 70,000 years ago , was controversial from its first proposal in the 1990s and by the 2010s had very little support . Distinctive human genetic variability has arisen as the result of the founder effect , by archaic admixture and by recent evolutionary pressures
Toba catastrophe theory
Toba catastrophe theory
Human evolution