I’D RATHER NOT: Meet the hominin species that gave us genital herpes.

Somewhere between 3 and 1.4 million years ago, HSV2 jumped the species barrier from African apes back into human ancestors – probably through an intermediate hominin species unrelated to humans. Hominin is the zoological ‘tribe’ to which our species belongs.

Now, a team of scientists from Cambridge and Oxford Brookes universities believe they may have identified the culprit: Paranthropus boisei, a heavyset bipedal hominin with a smallish brain and dish-like face.

In a study published today in the journal Virus Evolution, they suggest that P. boisei most likely contracted HSV2 through scavenging ancestral chimp meat where savannah met forest – the infection seeping in via bites or open sores.

Hominins with HSV1 may have been initially protected from HSV2, which also occupied the mouth. That is until HSV2 “adapted to a different mucosal niche” say the scientists. A niche located in the genitals.

Close contact between P. boisei and our ancestor Homo erectus would have been fairly common around sources of water, such as Kenya’s Lake Turkana. This provided the opportunity for HSV2 to boomerang into our bloodline.

Thanks for nothin’.