When evolution is not so slow and gradual

Jun 02, 2009

What's the secret to surviving during times of environmental change? Evolve…quickly.

A new article in The American Naturalist finds that guppy populations introduced into new habitats developed new and advantageous traits in just a few years. This is one of only a few studies to look at adaptation and survival in a wild population.

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 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. In the long run, survival of juveniles is crucial to the survival of the population, the researchers say.

The fact that fitness differences were found after only eight years shows just how fast evolution can work—for short-lived species anyway.

"The changes in survival in our study may initially seem encouraging from a conservation perspective," the authors write. "ut it is important to remember that the elapsed time frame was 13-26 guppy generations. The current results may therefore provide little solace for biologists and managers concerned with longer-lived species."

More information: Swanne P. Gordon, David N. Reznick, Michael T. Kinnison, Michael J. Bryant, Dylan J. Weese, Katja Räsänen, Nathan P. Millar, and Andrew P. Hendry, "Adaptive Changes in Life History and Survival following a New Guppy Introduction," The , July 2009.

Source: University of Chicago (news : web)

Explore further: How hummingbirds evolved to detect sweetness

add to favorites email to friend print save as pdf

Related Stories

Do female guppies risk their lives to avoid sex?

Jun 08, 2006

Sexual harassment is burden that females of many species face, and some may go to extreme lengths to avoid it. In a paper published in The American Naturalist, Dr Darren Croft from the University of Wales, Bangor and a rese ...

Female guppies risk death to avoid sexual harassment

Aug 06, 2008

Sexual harassment from male guppies is so bad that long-suffering females will risk their lives to escape it, according to new research from Dr Safi Darden and Dr Darren Croft from Bangor University. Their work, which was ...

Recommended for you

Researchers look at small RNA pathways in maize tassels

Aug 22, 2014

Researchers at the University of Delaware and other institutions across the country have been awarded a four-year, $6.5 million National Science Foundation grant to analyze developmental events in maize anthers ...

How plant cell compartments change with cell growth

Aug 22, 2014

A research team led by Kiminori Toyooka from the RIKEN Center for Sustainable Resource Science has developed a sophisticated microscopy technique that for the first time captures the detailed movement of ...

Plants can 'switch off' virus DNA

Aug 22, 2014

A team of virologists and plant geneticists at Wageningen UR has demonstrated that when tomato plants contain Ty-1 resistance to the important Tomato yellow leaf curl virus (TYLCV), parts of the virus DNA ...

User comments : 0