In evolutionary biology, a group of organisms share common descent if they have a common ancestor. There is strong evidence that all living organisms on Earth are descended from a common ancestor, called the last universal ancestor

Designed by Michael Bancroft.
You can buy this t-shirt from Threadless.
 

When a chameleon dates a rhino… we get the Chamaeceros Unicornis! A beautiful and rare specie.
T-shirt design by vcalahan
You can buy this t-shirt from springleap.com