Our Sex Life Tough on Frogs

Read how human pregnancy tests and "the pill" have had negative effects first on African clawed frogs and now on amphibians in general.

"Of equal concern is many of the common drugs we consume. Their contents pass through our bodies, into sewage treatment plants and back into our rivers and streams. Estrogen, the active ingredient in many birth control pills, is one of these. In frogs, low levels of estrogen cause exposed tadpoles to become female; under normal conditions, half develop female and half develop male," wrote Dr. Jeffrey Bonner, president, St. Louis Zoo.