Most of Us Have Herpes Thanks to Ancient Interspecies Sex (Probably)

Herpes is super common among humans. 50 to 80 percent of U.S. adults and more than
2/3 of the world population have it. And pretty much everyone will be exposed to
it in their lifetime. But where did exactly did it come from? Herpes simplex is a virus and there are two
types. Oral is Type 1 and genital is Type 2 — when
it comes to oral we’ve always had it. The virus has been with us since we before
we were considered “modern humans.” but Type 2 — genital herpes is new! Evidence shows that when we split from our chimpanzee common ancestor about 7 million years ago, we did not have
the herpes simplex 2 virus. Then somewhere between 3 and 1.4 million years
ago, we got it. The carrier, it seems, was an intermediate
species unrelated to humans called Paranthropus boisei, which
was “a heavyset bipedal hominin with a smallish brain and dish-like face.” What a hottie. This hominin likely contracted the virus by
scavenging infected ancestral chimp meat. The virus would have passed from kill to killer
through a bite or open sore. And the new virus then shared mouth-space
with the simplex 1 virus. Over time found a happier home in a different
“mucosal niche.” The genitals. It got to us because P. boisei and our direct ancestors Homo erectus lived
in close enough proximity for the two genetic lines cross and share the virus. There’s evidence that the Homo erectus butchered
and hunted its food, which means our ancestors likely got the herpes type-2 virus by eating
infected meat… But… it’s also possible that we got it
through interspecies intercourse with anthropological hottie P. Boisei. From there it was passed around from mother
to child and plain ol’ exposure. As weird as this is to think about… it actually
says a lot about the resilience of viruses. It’s not common for a virus to transfer
between species, though we are seeing a rise in this happening with things like swine flu,
bird flu, ebola, and even HIV. It can, unfortunately, happen innocuously
in some instances, say a chance encounter with a sick animal while traveling abroad. But in most cross-species cases, the virus
needs a lucky genetic mutation and a lot of fluid exchange for this to happen, which is
consistent with BOTH consuming meat and hot ancient interspecies sex. It also helped that P. boisei [boys-ee-eye],
though not a direct relative, was closer to homo erectus than some other more distant
mammals. Close genes allow a virus to infect a new
host more easily, and now it’s primed to spread through the new species. So, herpes and humans have a pretty long shared
history. Thanks to either meat eating, or … well
you get it. Welcome home herpes, I guess? For more, and only sometimes super gross,
science videos, be sure to subscribe. Luckily, we’re getting better at managing
those cross-species viruses, but how close are we to curing HIV? We did a video about it here. Even worse than trans-species viruses? Two pathogens can also and morph in your gut,
turning into a brand new and potentially deadly virus! Yay!