We've seen in our simulations that the more brightly colored a male guppy is, the more likely he will be seen -- and eaten -- by a predator. In a simulation or in the wild, where predators are ...

Meet Poecilia vivipara—a small, shiny yellow guppy found in South America. When a group of scientists visited the Fernando de Noronha archipelago a decade ago, they found the tiny freshwater fish.