Fig 1. The geographic distribution and population history of chimpanzees.

A, The ranges of each chimpanzee subspecies within western and central Africa. Range data extracted from the map of chimpanzee geographic range from [21]. Map of Africa modified from public domain source [88]. B, Phylogenetic relationships amongst chimpanzees and the timing of their population divergence, modified from [20]. 1 kya: Long term effective population sizes until 1 kya; present: effective population sizes from 1 kya to present. C, Heterozygosity, reflective of relative differences in effective population sizes. Box plots show median central interquartile range, whiskers the upper and lower interquartile range. Points show individual heterozygosity. For all panels, colour designates subspecies: Blue = western, red = Nigeria-Cameroon, green = central, orange = eastern.