I'm not a member yet.
A lot of people, myself included, have suspected that, but the problem is that repeated experiments which have tried to induce genetic change by direct environmental stimulus have always turned up negative results. To put it in an over-simplified way, cutting off mice tails doesn't mean their offspring will be born with shorter tails. Giraffes didn't grow longer necks by stretching them feeding from tall trees. It's just the ones with longer necks had a better chance of reproducing more effectively and so passed that on to their offspring.