A Toxic Hand-Me-Down

Environmental contamination can cause cancer and birth defects. Of particular concern are a group of toxic chemicals called endocrine-disrupters, which interfere with reproductive hormones and may cause sterility. A new study, published online this week in the Proceedings of the National Academy of Sciences, suggests that these chemicals can change reproductive behavior as well, and that these behavioral changes can be passed on from parents to offspring. If correct, these changes could alter the course of evolution by giving natural selection new targets to act on.