There’s “herpes” and then there’s “Oh my God, I’ve got herpes!” The former is the herpes simplex virus 1 (HSV1) which results in cold sores. The latter is the herpes simplex virus 2 (HSV2) which results in genital herpes and causes sores in the groin area, fever and body aches. There’s no cure for herpes so there’s usually a lot of animosity towards those who spread this STD. Some of that anger is also directed towards the prehistoric male (you know it was a male) who got the first case of herpes from an ape or chimpanzee. He’d probably say (or grunt) that he picked it up from eating their flesh, but his many sore mates would undoubtedly suspect otherwise. Researchers have recently discovered the Herpes Caveman Zero – a mysterious hominin species nicknamed Nutcracker Man. Did he get it from one of his mates who used a club to make sure no one else got his herpes?

Anthropologists have known that the last common ancestor of apes and humans carried HSV2 but only passed it on to the ape side some 7 million years ago. However, somewhere between 3 and 1.4 million years ago, our human ancestors got it back. In research published in Virus Evolution, Dr. Charlotte Houldcroft of the University of Cambridge has identified the first infectee as the Plio-Pleistocene hominin Paranthropus boisei, — the Nutcracker Man. Discovered in Tanzania in 1959 by the famous archaeologist-paleontologist Mary Leakey, he got the nickname because his thick skull, enormous teeth and massive jaw made him look like a chestnut-crunching caveman.

But how did he get herpes and how did he pass it on to Homo erectus? This is where it gets gross – and not in the way you might think. Study co-author Simon Underdown, a paleoanthropologist at Oxford Brookes University in England, tells how they found the answer.

“Climate fluctuations over millennia caused forests and lakes to expand and contract. Layering climate data with fossil locations helped us determine the species most likely to come into contact with ancestral chimpanzees in the forests, as well as other hominins at water sources.”

The researchers determined that Nutcracker Man liked to eat his nuts with a side of raw chimpanzee meat and that’s how he picked up HSV2. While Homo erectus, the human ancestor roaming around at the time, didn’t have the same craving for chimp, he did have a taste for his smaller and slower counterpart – Nutcracker Man. By eating the flesh of P. boisei, along with drinking from the same ponds, Homo erectus picked up genital herpes and began passing it around to his female friends and down to his offspring.

So the demise of poor misshapen Nutcracker Man was caused by his love of chimp meat and his own tasty legs, thighs and breasts. Will that make you likely to forgive him for giving us herpes? That probably depends on whether you have it or not.