Pregnant Males

Strange and disturbing news from National Geographic News this month that a new study shows that one of the most common weed killers in the United States can make male frogs lay eggs.

Atrazine, a widely-used pesticide used croplands in the U.S., is an endocrine disruptor. That means that it is a substance that interferes with animals' reproductive systems.

Previous research had shown that atrazine could give male amphibians female characteristics. New research has discovered that the chemical transforms male frogs into fully functioning females.

Atrazine "Keeps Coming Back"

Of 40 genetically male African clawed frogs used in the experiment, 4 of the adult frogs—or ten percent—developed into what looked like perfectly normal females.

As always with this type of discovery, if you're not concerned with the impact on wildlife, consider the human implications. Though there haven't been many studies on the chemicals' impacts on people, some recent research has linked atrazine exposure to breast cancer.
The U.S. Environmental Protection Agency recently announced it's reevaluating atrazine. The chemical has been banned in the European Union since 2004.