Whether you have recognized it or not, there is a revolution going on in biology, especially in our genes. Traditionally, as far as genetics goes, we eventually become what our genes dictate. Simply put, if 
we inherit a gene from our parents (either our mother or father), then that gene will tell our bodies how to grow, what height, weight, hair or eye color among a million other things we will have. This has been called “the modern synthesis.” Well, it now appears that nothing is so accommodatingly simple when it comes to our bodies.
In the past few years it has become increasingly clear that we have some “control” over our genes after all. Studies have shown that when a normal rat is fed a high fat diet it becomes…well, fat. That’s not the interesting part, however. When that fat rat is mated with a normal rat, the rat pups then have a tendency to become fat, even though they do not have the gene to predispose them to become such. The fat parent rat has managed to pass on the ability to become fat to their offspring by another mechanism not directly involving DNA. This ability is termed “epigenetics,” meaning “around or above” the gene. This and many other studies have shown that in mammals, at least, we can give “good or bad” qualities to our children that aren’t in our genes or DNA by adjusting our “actions.”
Exercise, for example, can pass on favorable characteristics to our children, even if we do not possess those “good” genes to begin with. This has huge ramifications. We are able to turn good genes “on” or bad genes “off” by our own activities. We are not simply slaves to our genes as once thought and we can pass this information on to our children an future generations.