Monsanto’s Roundup, which is the most popular herbicide used today, has been found to ignite morphological changes in amphibians. The research, conducted using tadpoles, found that environmentally relevant concentrations of Roundup are enough to cause two species of amphibians to actually change shape. This is the first research to show that herbicides can have such an affect on animals. 

Setting up outdoor tanks closely resembling the environment of natural wetlands, study researcher Rick Relyea, University of Pittsburgh professor of biological sciences in the Kenneth P. Dietrich School of Arts and Sciences and director of Pitt’s Pymatuning Laboratory of Ecology, added 3 tadpoles to each tank and exposed them to a range of Roundup concentrations over a 3 week period. The cages also contained large predators, which naturally cause changes in tadpole morphology. These natural changes include a larger tail, due to chemical emissions. 

While it wasn’t surprising to see morphological changes take part due to the naturally emitted chemicals from predators, it was rather shocking to find out that Roundup had the same effects — causing the tails of the tadpoles to grow in size. What’s more, the combination of the naturally emitted chemicals and Roundup caused the tadpoles’ tails to grow twice as large. Seeing as tadpoles alter body shape in order to properly survive in its environment, the forced changes from herbicides like Roundup can put the animals at a disadvantage.

“This discovery highlights the fact that pesticides, which are important for crop production and human health, can have unintended consequences for species that are not the pesticide’s target. Herbicides are not designed to affect animals, but we are learning that they can have a wide range of surprising effects by altering how hormones work in the bodies of animals. This is important because amphibians not only serve as a barometer of the ecosystem’s health, but also as an indicator of potential dangers to other species in the food chain, including humans,” says Relyea.

In addition to physically altering tadpoles, Roundup has also been shown to be contributing to the decline of butterfly populations, though in a different way. Similar to how pesticides have been contributing to the bee decline, Monsanto’s Roundup has been tied to the decrease in the population of monarch butterflies by killing the very plants that the butterflies rely on for habitat and food.

As more research continues to be done, researchers continue to keep finding more pitfalls caused by Monsanto’s creations. We currently know enough to cease use of the corporation’s products, but there are undoubtedly further concerns yet to be revealed.