Washington, June 11 (ANI: A new study has found that guppy populations introduced into new habitats adapt to the surroundings in just a few years, developing new and advantageous traits.
As part of the study, a research team led by Swanne Pamela Gordon from the University of California, Riverside studied 200 guppies that had been taken from the Yarra River in Trinidad and introduced into two different environments in the nearby Damier River, which previously had no guppies.
One Damier environment was predator-free. The other contained fish that occasionally snack on guppies.
Eight years after their introduction, the team revisited the Damier guppies to see what adaptive changes they might have picked up in their new environments.
The researchers found that the females had altered their reproductive effort to match their surroundings.
In the environment where predators were present, females produced more embryos each reproductive cycle.
This makes sense because where predators abound, one might not get a second chance to reproduce.
In less dangerous waters, females produced fewer embryos each time, thus expending fewer resources on reproduction.
Finally, the researchers wanted to see if these adaptive changes actually helped the new population to survive.
So, they took more guppies from the Yarra, marked them, and put them in the Damier alongside the ones that had been there for eight years.
They found that the adapted guppies had a significant survival advantage over the more recently introduced group.
In particular, juveniles from the adapted population had a 54 to 59 percent increase in survival rate over those from the newly introduced group.
According to the researchers, in the long run, survival of juveniles is crucial to the survival of the population.
The fact that fitness differences were found after only eight years shows just how fast evolution can work for short-lived species. (ANI)