Evolution: ain't it grand?

When I think about evolution, I think about that beardy guy, you know, what’s his face, Chuck Darwin, and his Snoopy ship, studying finches or whatever at Easter Island. Or the Galapagos, whichever one has the giant super old turtles. Or I think about Lucy, or that picture where the guy gets increasingly better posture. Anywho, all that stuff happened like forever ago, right? And it takes a gazillion years for things to change perceptibly. That's what I thought, too. Turns out, we were wrong.

A new study shows that guppies (little fishies; not to be confused with yuppies, who are also evolving as they lose a little bit more relevance every single day), can adapt to new environments pretty quickly.

Scientists at the University of California, Riverside performed an experiment on 200 guppies in Trinidad. They removed the guppies from one river and introduced them to a river where no guppy population existed. They split the guppies into two groups, and placed one half in a predator-free area. They placed the other group in an area where fish who might consider the occasional guppy to be a tasty snack lived.

Just eight years later, the scientists found that the guppies had changed their reproductive habits. The guppies in the area where predators existed produced more eggs all at once, because they might only have the one chance to reproduce. The guppies in the less dangerous part of the river produced less embryos, in order to conserve energy and resources.

The scientists then wanted to see if these changes were actually making the guppies more successful at survival, so they took a new sample from the first river, marked them, and placed them in the second river with the population that had been there for eight years. The adapted guppies had a significantly higher rate of survival. The adolescents, especially, had a 54-59 percent increase in survival rate.

It’s pretty amazing that such a change was achieved after only eight years, but the scientists who conducted the study want to remind us that this time frame actually represents about 13-26 guppy generations. So such a rapid change in a longer lived species would be pretty unlikely.

(I wrote this for Science Buzz)