Table 1.

Description of demographic models tested with modern and ancient genetic data. Model 1 is based on BEMs calculated independently ‘within’ each time period, whereas model 2 is based on a conglomerate of ‘pooled’ climatic niche conditions experienced by the species throughout the Quaternary. Model 3 variants are based on models 1 and 2, but include potential bison population declines owing to hunting by humans.

	model 1	model 2
BEMs demographic model	single population between 42 and 30 ka; population splits between 30 and 21 ka; population merge between 11 and 8 ka, and split between approximately 5 and 1 ka	single population between 42 and 30 ka; population splits between 30 and 21 ka; population merge between 11 and 8 ka
BEM + end Pleistocene/Mid–Late Holocene decline (M3a)	BEM Model 1 + population decline between approximately 5 and 0.9 ka (M3a1)	BEM Model 2 + population decline between approximately 5 and 0.9 ka (M3a2)
BEM + historic decline (M3b)	BEM Model 1 + population decline between the approximately 0.3 ka and the present (M3b1)	BEM Model 2 + population decline between approximately 0.3 ka and the present (M3b2)
BEM + end Pleistocene/Mid–Late Holocene decline + historic decline (M3c)	BEM Model 1 + population decline between approximately 5 and 0.9 ka + decline between the approximately 0.3 ka and the present (M3c1)	BEM Model 2 + population decline between approximately 5 and 0.9 ka + decline between approximately 0.3 ka and the present (M3c2)