Human DNA is comprised of roughly eight percent ancient viral fragments, left over from infections that plagued our evolutionary ancestors millions of years ago.

A closer look

Human DNA is comprised of roughly eight percent ancient viral fragments, left over from infections that plagued our evolutionary ancestors millions of years ago. These retroviruses managed to embed their genetic code directly into the sperm and egg cells of early hominids, ensuring that their viral legacy would be copy-pasted into every single human born since. Placental development is actually dependent on one of these ancient viral proteins, meaning mammalian pregnancy literally would not exist without a prehistoric biological hijacking. We spend our lives taking vitamins, washing our hands, and aggressively avoiding sick people, completely ignoring the fact that our own genome is basically a scrapyard for extinct infectious diseases. It is a delightful paradox that humanity owes its very existence to a random viral infection that decided to make itself a permanent roommate in our evolutionary blueprint