Male fish start making female egg proteins.
Panthers are born with undescended testicles. Male alligators have such small penises they cannot reproduce. Research experiments with laboratory animals also show the effects of endocrine disruption on mammals. Many scientists believe that the weight of evidence points to endocrine disruption as a human reality. For example, pesticide exposure to the pregnant mother has been shown to have a definite effect on children's neurological behavior, and other chemical compounds can even cause lowered intelligence.