An interesting study in historical genetics

HIV dates back to around 1900, study shows

Scientists have take three samples: One from the earliest known infection in the US--1981, one from the earliest known infection in Africa--1959, and lymph node tissue from a woman who died in Africa in 1960, and have traced through the mutations to a time period between 1884 and 1924. The study suggests that the building of colonial cities at the time allowed the virus to take hold, as there was a higher, urban population and prostitution to help its spread. They believe AIDS was not initially recognised at that time because of the general conditions in colonial Africa and the many Africans who died of diseases and wasting at that time.