Weed killer causes animal shape changes

PITTSBURGH, April 2 (UPI) -- The world's most popular weed killer can induce morphological changes in vertebrate animals, U.S. biologists studying its effect on amphibians say.

University of Pittsburgh researchers said the weed killer Roundup, in sub-lethal and environmentally relevant concentrations, caused two species of amphibians to change their shape.

The study is the first to show that a pesticide can induce morphological changes in a vertebrate animal, biological sciences Professor Rick Relyea said in a university release Monday.

Roundup is a systemic, broad-spectrum herbicide produced by the U.S. company Monsanto.

The presence of predators can cause tadpoles to change shape by altering the tadpoles' stress hormones, Relyea said, causing them to grow bigger tails to better escape. Read More