Ancient Viruses in Our DNA

A huge chunk of your DNA is actually ancient viruses. Seriously. About 8% of the

human genome is made up of the leftovers of infections that happened to our ancestors millions

of years ago. These viruses literally wrote themselves into our DNA, and that code got

passed down through generations. Most of it is inactive, just sitting there like old files on

a computer. But some of it has been repurposed by our bodies to do important things,

like helping with pregnancy. So you're basically part human, part ancient viral

fossil. Your body is a living archaeological site.