Frogs, salamanders and other amphibians have shown high rates of deformation in recent years, and scientists are trying to find out why. Possible causes include inbreeding, parasites or pollution that seeps in through the amphibians’ skin.
The deformities include five-legged salamanders and frogs with extra limbs. One new study of tiger salamanders rules out inbreeding as the cause. That conclusion shifts the blame to human activity as the most likely culprit.