Primate phylogeny. The ability of mirror self awareness probably evolved around 18 million years ago with great apes (chimpanzees, bonobos, orangutans and gorillas) common ancestors Image from www. mun.ca
A gibbon seems to be interested in itself, but none tried to get at icing on their own faces (Image: Emma Collier-Baker) Photo from www.newscientist.com
The gibbons sometimes tried to reach around the mirror to get at the ape on the other side (Image: Emma Collier-Baker) Photo from www.newscientist.com
Read more about "The evolution of primate visual self-recognition: evidence of absence in lesser apes" by Suddendorf and Collier-Baker, 2008 (full article) (abstract).
"King of the swingers has no use for mirrors" by Ewen Callaway on Newscientist.com
Suddendorf T. Collier-Baker E. 2008. The evolution of primate visual self-recognition: evidence of absence in lesser apes. Proceedings of the Royal Society B (http://rspb.royalsocietypublishing.org/content/early/2009/02/21/rspb.2008.1754.full