Guppies, a perennial pet store favorite, have helped a UC Riverside scientist unlock a key question about evolution:
Do animals evolve in response to the risk of being eaten, or to the environment that they create in the absence of predators? Turns out, it’s the latter.
Guppies, a perennial pet store favorite, have helped a UC Riverside scientist unlock a key question about evolution:
Do animals evolve in response to the risk of being eaten, or to the environment that they create in the absence of predators? Turns out, it’s the latter.
David Reznick, a professor of biology at UC Riverside, explained that in the wild, guppies can migrate over waterfalls and rapids to places where most predators can’t follow them. Once they arrive in safer terrain, Reznick’s previous research shows they evolve rapidly, becoming genetically distinct from their ancestors.
“We already knew that they evolved quickly, but what we didn’t yet understand was why,” Reznick said. In a new paper published in American Naturalist, Reznick and his co-authors explain the reason the tiny fish evolve so quickly in safer waters.
To answer their questions, the scientists traveled to Trinidad, guppies’ native habitat, and conducted an experiment. They moved guppies from areas in streams where predators were plentiful to areas where predators were mostly absent. Over the course of four years, they studied how the introduced guppies changed in comparison to ones from where they originated.
Read more at University of California-Riverside
Image: Guppies swim near the Quare River in Trinidad, where conditions are right for observation with and without predators. (David Reznick/UCR)
