Saddam Hussein would have to wait 20 years to realize his dream of a perfect army. And the Donald Trumps of the world would also have to enlist thousands of women to be the mothers of their clones. For all their efforts, those seeking to mass-produce children in this way, as well as others who seek an exact copy of someone else, would almost certainly be disappointed in the end. Although genes contribute to the array of abilities and limits each of us possesses, from conception forward their expression is constantly shaped by environmental factors, by the unique experiences of each individual and by purely chance factors in biological and social development. As one wit has observed, someone trying to clone a future Adolf Hitler might instead produce a modestly talented painter.
Cloning seems to have no ill effects so far.
Dolly, the first mammal ever to be cloned, gave birth in 1998 to Bonnie, who by all accounts is normal. This past year Dolly delivered a healthy set of triplets. Since the birth of Louise Brown, assisted-reproduction technologies have made remarkable progress in helping infertile women and men become parents. Women with blocked or missing fallopian tubes, which carry the eggs from the ovaries to the womb, can now use in vitro fertilization to overcome the problem, and those without a functional uterus can seek the aid of a surrogate mother . A male who produces too few viable sperm cells can become a father using the new technique of intracytoplasmic sperm injection , which involves inserting a single sperm or the progenitor of a sperm cell into a recipient egg.