Mutations alter the information contained in genes. "Epigenetic" marks on genes do not affect the information but do influence gene activity, as the simplified diagrams below show.
For more on epigenetics, check out Epigenetics Offers New Clues to Mental Illness in the December 2011 issue of Scientific American, an online-only animation Inheritance of Acquired Characteristics and an installment of our ScieneTalk Podcast The Mind's Hidden Switches.
Illustrations by AXS Biomedical Animation Studio
