Healthy frogs can mysteriously reverse their sex
Frogs have been shown to reverse their sex in polluted suburban ponds. Now, the same has been shown to happen in more pristine forests.
What determines whether an animal becomes male or female? For frogs, sex is much more complicated than we thought.
For some creatures, like reptiles and fish, sex can be heavily influenced by the environment. Sea turtles that grow up in warmer sand are more likely to become female, for example. Mammals, however, are much more bound to genetics: If you’re genotypically male in the womb, you’re likely to develop outwardly as such.
Amphibians such as frogs lay somewhere in the middle. They’re mainly influenced by genetics, but the environment also plays a role. In the laboratory, certain pollutants like synthetic estrogens and herbicides have been shown to induce genetically male frogs to develop outwardly as females.
Research has also begun to