Herpes is one of the most common diseases, and it affects both animals and people. Two-thirds of the world population have been diagnosed with this simplex virus. However, it wasn’t known until now when was the first time that a living being caught genital herpes. According to British researchers, it all started a million years ago due to an ancient primate ancestor: the Paranthropus boisei.

Herpes simplex was genetically passed since the earliest of human-existence through all our lineage split. According to the study published on Sunday in the journal Virus Evolution, the Paranthropus boisei is one of the first primates in the human-evolution history, and today we can blame it for being who started spreading this sexually-transmitted disease that affects both men and women.

This Paranthropus Boise was an ancient chimpanzee with really huge teeth – so great scientists also dubbed it “Nutcracker Man.” It measured about 4 feet tall and had an enormous skull compared to the size of its brain. It had a broad, dish-like face, and massive chewing muscles.

Paranthropus boisei
Researchers claim the primate ancestor measured about 4 feet tall and had a large skull.

However, there are different kinds of herpes which most people don’t know. In fact, there are more than 100, but only eight regularly infect human – provoking painful diseases like chickenpox and mononucleosis.

People mostly know two types of deadly herpes simplex viruses: HSV-1 and HSV-2. The first one is always transmitted orally, and the second is typically sexually transmitted.

All gorillas or chimpanzees can get infected from herpes simplex. “Every other species of primate only has one kind of herpes simplex virus,” said the virologist at the University of Cambridge in England, Charlotte Houldcroft. She and her group believe Paranthropus boisei and Homo erectus are the very reason why people started suffering from this virus.

“We can use data from diseases to reconstruct events that are completely invisible to the archaeological and fossil records,” Houldcroft said. “The signals in the HSV-2 virus are records of direct contact between the ancestors of us and chimps that we can tangibly now ‘see’ and gives us direct insight into the daily lives of our ancestors.”

Researchers said that Paranthropus Boisei only orally transmitted herpes simplex 1, or HSV-1. Unlike HSV-1, genital herpes or HSV-2 indeed has been circulated through sexual activity. This last type of herpes has evolved, and now it could be spread orally.

The Washington Post reported in 2014 that HSV-1 has been present in chimpanzees and been transmitted orally since more than 6 million years ago – compared to HSV-2, which reached the human lineage more recently, around 1.4 million years ago.

How herpes jumped from monkeys to humans

The British team organized the human ancestors using a statistical model called a Bayesian network, thus to determine which link had each chimpanzee that could be related to the beginning of herpes transmission.

The scientists collected half a dozen possible culprits from 30 different prehistoric species. They believe that ancient patient zero had to share paleontological time and geographic space with a human ancestor.

Image result for Paranthropus boisei
The skull of the Paranthropus boisei displayed after intensive cleaning and preserving. Image Source: U Ciencia

Virologist Houldcroft suggested that the most visible link that would explain the beginning of herpes simplex virus would be between boisei and the Homo erectus. “It was almost like a murder mystery: Who had motive and opportunity? Who was in the right place at the right time?” Houldcroft said.

The researchers discovered that this ancient chimpanzee might sexually be transmitted herpes to another of our lineage, but closer to the Homo sapiens sapiens.

How did the Paranthropus boisei spread genital herpes through humankind?

In Africa, in a zone where scientists believe monkeys evolved to modern humans, the Homo erectus sexually encountered the boisei and get infected from HSV-2, between 1.4 million and 3 million years ago. However, the sexual contact is only a hypothesis. This disease could also be transmitted through bites or scratches, which would transfer the virus through sores.

“Essentially, when humans migrated out of Africa, they already carried HSV-2, and wherever humans went, their viruses went too,” Houldcroft said. “HSV-2 infects for life and can be passed from mother to baby or between sexual partners, which made sure it successfully spread wherever humans did.”

It is possible that herpes didn’t start to spread because of sexual intercourse. In fact, Houldcroft believes violence play a bigger role in this puzzle. “You can speculate in any scurrilous way that you like because we can’t be sure.”

Houldcroft said that the Homo erectus maybe killed and ate the Paranthropus boisei, or maybe this closer ancestor wore its skin to protect from the cold and get infected. Perhaps, it was the same boisei who jumped and attacked the Homo erectus as a way to defend itself.

“We can ‘blame’ our ancestors for eating other hominins/great apes, this has been the source of other primate-to-human infections such as HIV,” said Houldcroft. “Eating other species closely related to oneself has risks, because pathogens adapted to species genetically similar to us will find it easier to jump the species barrier.” – CNN reported

The virologists suggested that more research will have to be done to have a better conclusion.

Source: Virus Evolution