STD Origin Solved: The Neanderthals Gave Us Genital Warts

We now know who are to blame for the modern genital warts. A study published in Molecular Biology and Evolution has figured out the origin of human papillomavirus (HPV), the most common sexually transmitted infection in the world.

According to the study, HPV has been introduced to humans because Homo sapiens, our ancestors had sex with Neanderthals and Denisovans roughly around 100,000 years ago.

As explained by Science Alert, researchers from the National Centre for Scientific Research in France and Spain's Catalan Institute of Oncology ran 118 full sequences of HPV16 from five different subtypes of the virus to see how it evolved. HPV16 is the most oncogenic infectious agent among humans and responsible for most genital cancers. While much of the world is struggling to combat it, the sub-Saharan Africa are generally HPV16-free.

After analyzing the viruses' structures, they came up with a genetic timeline that shows how the virus has evolved through the years. The timeline showed that the HPVs go back almost half a million years, and likely arose within Neanderthal and Denisovan populations.

How did the virus spread? And why is the sub-Saharan Africa HPV16-free?

The researchers suggest that early humans already had their own strains of HPV. However, HPV16 specifically plagued the modern humans after our ancestors left Africa some 60,000 to 100,000 years ago and spread across Eurasia.

As they moved, they came across Neandethals and Denisovans who had already developed the HPV 16a after they have left Africa long before humans did. The early humans mated with them and that was when they acquired the HPV 16a.

"In those times, there was no safe sex, everything was transmitted," Ville Pimenoff, a genetics researcher at the Catalan Institute of Oncoloy in Spain told Vox.

The fact that we interbred with other species can explain how humans acquired new DNA after leaving Africa. But as Pimenoff said, "the real big picture is that our history, our evolutionary history is a lot more complex than we thought 5 to 10 years ago. And our history, is also the history of our pathogens."