Fig 1.
Irisk (lowest value of inbreeding depression parameter I that results in at least one extinction event in ten simulation runs) and Isure (lowest value of inbreeding depression that results in extinction in all simulation runs) for various initial population sizes N0 and fi = 50% (for fi = 30;70, see S1 Appendix). The horizontal dotted lines mark the range of values of I observed in AMHs.
Fig 2.
Allee effects, with and without stochasticity.
(a) Arisk (lowest value of Allee parameter A that results in at least one extinction event in ten simulation runs) and Asure (lowest value of Allee parameter A that results in extinction in all simulation runs) for various initial population sizes N0. (b) Birth intervals corresponding to Arisk and Asure, as well as birth intervals corresponding to the Asure values obtained in the non-stochastic matrix model (labeled Asure(MM)). The horizontal dotted lines mark the range of values of birth intervals observed in contemporary hunter-gatherers.
Fig 3.
Inbreeding, Allee effects, and stochasticity.
Arisk (lowest value of Allee parameter A that results in at least one extinction event in ten simulation runs) for a scenario without inbreeding (blue triangles; Arisk(0)) and a scenario with inbreeding (orange squares; Arisk(3.2)) (inbreeding depression parameter at I = 3.2).