Fig. 2

Demographic history affects the proportion of deleterious variants in the human population. The proportion of deleterious variants currently segregating in the population can vary depending on the past demographic regime of each population. Under a regime of demographic expansions alone, populations display higher levels of genetic diversity (in total absolute counts) and lower proportions of deleterious variants (in brown) than under regimes in which populations have experienced bottlenecks or recent founder events, where the opposite patterns are observed. The schematic demographic models presented here illustrate the broad demographic history of some modern human populations (e.g., Africans, Europeans, and French Canadians), but they do not attempt to capture their precise changes in population size over time