Researchers have traced the origin of genital herpes back to an ancient hominin relative, LiveScience reports.
"Herpes [viruses] infect everything from humans to coral, with each species having its own specific set of viruses," Cambridge University's Charlotte Houldcroft says in a statement. "For these viruses to jump species barriers, they need a lucky genetic mutation combined with significant fluid exchange. In the case of early hominins, this means through consumption or intercourse — or possibly both."
Herpes simplex virus 2, which causes genital herpes, didn't co-speciate alongside humans, as did HSV1, which causes cold sores, Houldcroft and her colleagues say in Virus Evolution. Instead, HSV2 jumped into humans from another species between 1.4 million and 3 million years ago. The researchers then turned to a network analysis to work out how HSV2 moved from the ancestors of modern chimpanzees to the ancestors of modern humans. From this, they homed in on Paranthropus boisei as the likely source of genital herpes as it was in the right place at the right time and overlapped with Homo erectus.
LiveScience notes that P. boisei is also known as the "Nutcracker Man" as it has large jaws and molars.