Retrovirus invading a cell and integrating with its DNA
ERVs provide clear evidence that different kinds of living things are related.

ERV stands for Endogenous RetroVirus. Don't be put off by the technical-sounding vocabulary. The ideas behind it are simple to understand, and this wiki is aimed at explaining them.

A retrovirus is a virus that infects the cells of a creature. Once inside a cell, the retrovirus inserts a copy of itself into a cell's DNA.
The cell's normal DNA reading facilities are 'fooled' into reading the copy and producing more retroviruses. Click on more.jpg for more details about the operation of retroviruses.

The word 'endogenous' just means originating from within the body, rather than outside of the body.
But how can a virus originate from inside the body? Surely, they originate from outside the body? They invade it, don't they? Click on next.jpgto find out how.

(Note to contributors. The plan is to produce a resource explaining what ERVs are and how they provide evidence for common ancestry, presenting it in a manner that is as accessible as possible. I think this is best done in a top-down way, providing links so that people can drill down into any aspect of the topic for more and more detail. There is plenty of good material on the web, but it is not always pulled together, and is not always as accessible as it could be. If you think you can contribute this project, please click on the 'Join' link at the bottom of the page.)