New research into HIV's genesis:

By comparing the two sequences with more recent ones, Gemmel was able to show that HIV-1 first entered humans about 1908, not 1931, as earlier analyses with just the 1959 sample found. Her analysis also indicates that the virus existed in low levels in humans until the middle of the 20th century. “That matches the rise of population centers,” Gemmel explained, suggesting that urbanization around that time paved the way for the AIDS epidemic.

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