1. 2009

2. FOXP2  = forkhead box 2  mutation in this gene were found in families that have a high incidence of abnormalities in speech and grammar  only one aminoacid substitution had occured in the 130 Myr separating mice and ancestor of humans and chimpanzees  two substitution occured in the human lineage during the 4-6 Myr since it separated from chimpanzees!  this gene is virtually invariant in another 28 orders of mammals that last shared common ancestor around 100 million years ago  (Futuyma, D.J., (2005) Evolution. Sinauer Associates, INC. Sunderland, MA,USA. p. 455)

3. MYH  = sarcomeric myosin heavy chain  MYH is highly expressed in the chewing muscles of chimpanzees and is responsible for the large size of these muscles in this and other non-human hominins  in humans, MYH has been inactivated by a frameshift mutation that occured about 2,4 Myr

4. OR  = olfactory receptor genes  these are approximately 1200 functional OR genes in the mouse genome, but only 550 in humans  = apparently selective pressures to maintain OR gene functionally are relaxed in humans

5. Olfactory Receptor Genes  the remote ancestor of mammals carried a single gene for detecting odors that has been duplicated many times  as a result, humans today have about 1 000 olfactory receptor genes  mice have 1 300  more recently, about 60% of human olfactory receptor genes have been inactivated by mutations  whereas mice have lost only 20% of theirs  …this dramatic difference demonstrates that a versatile sense of smell is more important to mice than it is to us!