Consider a species of primate that originally lived only in…

Consider a species of primate that originally lived only in Africa expanded its range through Europe, then North Asia, and finally to the Americas. How would you expect heterozygosity for most loci to differ among populations in Africa, Europe, North Asia, and the Americas (where is heterozygosity highest vs lowest)? Why? Compared to the original African populations, which population would you expect to be most genetically similar? Which population would you expect to be the most different?