Friday, September 4, 2009
"In biology, the term epigenetics refers to changes in phenotype (appearance) or gene expression caused by mechanisms other than changes in the underlying DNA sequence, hence the name epi- (Greek: over; above) -genetics. These changes may remain through cell divisions for the remainder of the cell's life and may also last for multiple generations. However, there is no change in the underlying DNA sequence of the organism; instead, non-genetic factors cause the organism's genes to behave (or "express themselves") differently."
- from Wikipedia: Epigenetics.
Basically, epigenetic factors like molecular structures suppressing or activating sections of DNA by pressing on them or pulling them out a bit can cause the genetic code to cause the body to react in certain ways. Things like smoking, activity level (exercise), diet and various environmental factors can affect this.