The term "epigenetic" refers to an effect or condition that arises from non-genetic influences on gene expression. Those influences can include environmental conditions, stress, a person's emotional state, or physical trauma. Specifically, these effects are heritable, but that heritability does not occur through the normal mechanisms by which genotypes are passed from one generation to the next--hence the prefix "epi-" which means "on, upon, or above."The idea that experiences, emotions, responses, etc. can influence an individual's genetic makeup is one that has fallen in and out of favor in past decades, which is somewhat understandable in that it seems to violate accepted hereditary science.However, experiments have shown that animals that are subjected to stresses or other stimuli and respond to them will