http://www.youtube.com/watch?v=hLZ7GqWpEqM 
The Biology of change- Bruce Lipton:

It’s not genes that control our lives?? Genes don’t control biology as was thought.  So what does? Bruce Lipton describes a different theory:

Continuously changing environmental signals influence our cellular signals, that influence the movement of proteins in our cells, which altogether influence our behaviour ... So basically our perception of our environment controls our genes' responses, which controls our reactions/behaviour.

So our genes are programmed but they have less to do with our behavioural response, they just provide the blue print and only once activated respond. So we are not a victim to our genes but a product of our perception and belief system.

This means that as we change our perception of our environment we can rewrite our genes.

So this can work in a positive/ growth direction, essential for health and healthy evolution but also can work in a defensive direction/ protecting the system, ie not growing... So if our perception of the environment is toxic- our response will be defensive and therefore not reproductive/ positive. Living in fear, for example, hinders positive growth, but feeling loved (the most influential signal, above nutrition!) enhances the growth of the individual.

Physiologically what’s happening is the Pituatory gland sends responses to environmental stress and responds in fight or flight.  If we are living predominantly in this stress response then we are shutting down the growth aspect ie the immune system suffers and we get sick. Also under stress we are less intelligent due to the blood flowing to the back brain (for flight or fight), not the frontal cortex. In general the population is stressed, therefore we are living less intelligently than what we could be.

Therefore our perception dictates individual health and thus our species’ evolution. The key lies in being able to adjust our perception.