James F. Crow as men age their sperm have more and more mutations

http://www.pnas.org/cgi/content/full/94/16/8380
When I'm not in class or in lab, I'm attending a seminar. Today's speaker James F. Crow gave a lecture on population genetics. His talk was remarkably coherent considering that the only genetics lectures I attended before were undergraduate classes taught by quirky professors who had the knack of zonking me out one-third of the way through despite their surreal humor.

I found this interesting: He concluded that many diseases caused by mutations in offspring were the result of fertile old men. His rationale was that the gametes of older men had gone through more cell divisions. More cell divisions mean more mutations since it increases the chance that there is a mistake whenever the genome divides. For women, it's different. By the time a female is born, all the eggs that she will ever produce during her lifetime are already present in the ovary.

A woman in the audience wondered about the social implications of this observation and inquired whether or not Dr. Crow was considering on pitching a proposal to Congress to discourage men 40 or over to not have children. Dr. Crow had no comment on that particular question.