When evolutionary biologist John Endler began studying Trinidad's wild guppies in the 1970s, he was struck by the wide variation among guppies from different streams, even among guppies living in ...

The male guppies that were depicted in this sexual selection model only begin to demonstrate the vast range of colors and patterns expressed by wild guppies. Below are some examples of wild ...

The researchers exposed progeny of wild-caught guppies to varying levels of fluoxetine, the antidepressant commonly sold ...