Figure 1.

Hominin host-switch model (modified from [1]). Schematic diagram of the pathogen evolution and distribution out-of-Africa with the corresponding ancestral hominin group. Since the migration of modern human ancestors to Eurasia 120,000–60,000 years ago, sexual transmission from Neanderthals, Denisovans, or other hominin groups (i.e., introgression and pathogen host-switch) likely introduced certain human papillomavirus, herpesvirus, and ectoparasitic pathogens to the arriving group of modern human ancestors in Eurasia.