This text challenges the accepted theory on the genetic mechanism of evolution. The traditional neo-darwinian view is that we are at the mercy of our genes which we inherit, largely unchanged, from our parents, apart from random mutations which accumulate and lead to change over evolutionary time. The work shows that for one adaptive body system there is strong molecular genetic evidence that aspects of acquired immunities developed by parents during their lifetime may be passed on to their children. This gives new credibility to the Lamarckian heresy - the notion of the inheritance of acquired characteristics, which has, until now, been refuted.