What Are Endogenous Retroviruses?

An Endogenous Rectrovirus is a viral sequence that has become part of the infected animal's genome. Upon entering a cell, a retrovirus copies its RNA genome into DNA, and inserts the DNA copy into one of the host cell's chromosomes.

Endogenous Retroviruses prove that evolution exists by showing up in other organisms and not just one organism. People share the same endogenous retroviruses that chimpanzees and other animals have.