News / Science & Technology

Study: Environment Speeds Evolutionary Change

Soil mites taken from the wild and raised in test tubes in the University of Leeds laboratory showed evolutionary changes over just 20 generations — a timespan of about 100 weeks — in response to their new environment. (Credit: Tim Benton)
Soil mites taken from the wild and raised in test tubes in the University of Leeds laboratory showed evolutionary changes over just 20 generations — a timespan of about 100 weeks — in response to their new environment. (Credit: Tim Benton)
Rosanne Skirble
A new study challenges the widely held belief that evolutionary changes in living organisms take place slowly, over hundreds, thousands or millions of years.

Researchers have found evidence species can evolve much more quickly when in response to environmental change.

Tim Benton studies how living organisms respond to changes in their environment. In a paper published in Ecology Letters, the professor of biological sciences at the University of Leeds in England examines why marine species, for example, have declined so rapidly in size and number over the past 50 years.

“Is this a response that is due to them having less food or the temperature of the water changing from climate change or is it a response that is due to natural selection working and evolutionary biology happening?” Benton said.

Study: Environment Speeds Evolutionary Change
Study: Environment Speeds Evolutionary Changei
|| 0:00:00
...    
🔇
X

To find out, Benton’s team of researchers conducted a series of laboratory experiments with soil mites, tiny spider-like creatures that, among other things, reproduce rapidly.
 
“We brought them in from the wild and put them in test tubes, where each test tube maintained about 1,000 individuals in a free running population. Every day, we just put in a little bit of food," he said. "And in some of the populations we took out juveniles and in other populations we harvested adults. And then we just left them to it over about 100 weeks.”  

That’s normally long enough for about 20 generations of soil mites. In their new test tube environments, the tiny creatures competed for food, sex and survival in different ways than they would have in the wild. And in charting the mites’ growth rates, genetics and reproduction over this relatively brief span of time, the scientists observed that natural selection produced significant evolutionary changes. For example, Benton said, the length of time the mites needed to reach adulthood doubled during the course of the experiment.

“Because it is taking them so much longer to grow up, then that means that the population responds to changes in a different way," he said. "Population growth rate is slower, which means that there are very large changes in population dynamics, the way the population size responds to environmental change in itself.”

According to Benton, the mite study suggests there is a powerful interplay between environmental and evolutionary change.

“And [after] one or two more complementary studies like ours in different groups, then people will quite happily accept, I think, the force of evolutionary change in ecological time," he said. "So over a single human life time, 100 years, there are likely to be very large changes and if we don’t start thinking about the evolutionary changes as well as the changes in the environment then the things we put in place to protect the species we want to manage won’t actually work.”

One place where this might have a critical impact is in fisheries management.

"Given that we are harvesting large animals all the time, that’s what we do when we go out fishing," he said. "The phenotypic response that we see in the reduction of size is likely to be an evolutionary response and that’s what we found in our laboratory study. So what that means is, if you stop fishing because your stock is getting depleted and the animals are increasingly smaller and smaller and smaller, there is no necessity that they will be able to recover because you’ve had a hard-wired evolutionary change. So they won’t just be able to spring back.”

There’s no guarantee that they will again grow larger and larger.

Benton added that environmentally-induced evolutionary changes could also have serious implications for other wildlife conservation efforts, as well as for disease and pest control programs.

You May Like

Myanmar Fighting Poses Dilemma for China

To gain some insight into conflict, VOA’s Steve Herman spoke with Min Zaw Oo, director of ceasefire negotiation and implementation at Myanmar Peace Center More

Australia Concerned Over Islamic State 'Brides'

Canberra believes there are between 30 and 40 Australian women who have taken part in terror attacks or are supporting the Islamic State terror network More

Recreational Marijuana Use Now Legal in Washington, DC

Law allows adults 21 and over to privately possess and smoke 0.05 kilogram of pot, and to grow small amounts of the plant More

This forum has been closed.
Comments
     
There are no comments in this forum. Be first and add one

Featured Videos

Your JavaScript is turned off or you have an old version of Adobe's Flash Player. Get the latest Flash player.
US Supreme Court Hears Hijab Discrimination Casei
X
Katherine Gypson
February 25, 2015 11:30 PM
The U.S. Supreme Court has heard opening arguments in a workplace religious discrimination case that examines whether a clothing store can refuse to hire a young woman for wearing the headscarf she says is a symbol of her Muslim faith. Katherine Gypson reports from the Supreme Court.
Video

Video US Supreme Court Hears Hijab Discrimination Case

The U.S. Supreme Court has heard opening arguments in a workplace religious discrimination case that examines whether a clothing store can refuse to hire a young woman for wearing the headscarf she says is a symbol of her Muslim faith. Katherine Gypson reports from the Supreme Court.
Video

Video Falling Gas Prices Hurt Nascent Illinois Hydraulic Fracturing Industry

Falling oil prices are helping consumers purchase cheaper petroleum at the pump. But that’s made hydraulic fracturing or “fracking” less economically viable for the companies in the United States invested in the process. VOA’s Kane Farabaugh reports on one Midwestern town that was hoping to change its fortunes by cashing in on the next big U.S. oil boom.
Video

Video Fighting in Sudan's South Kordofan Fuels Mass Displacement

Heavy fighting in Sudan's South Kordofan state is causing hundreds of thousands to flee into uncertain conditions. Local aid organizations estimate as many as 400,000 civilians have been internally displaced since the conflict began more than three years ago, while another 250,000 have fled across the border to refugee camps in South Sudan. VOA's Adam Bailes reports.
Video

Video Lao Dam Project Runs Into Opposition

A Lao dam project on a section of the Mekong River is drawing opposition from local fishermen, international environmental groups and neighboring countries. VOA's Say Mony visited the region to investigate the concerns. Colin Lovett narrates.
Video

Video A Filmmaker Discovers Her Biracial Identity in "Little White Lie

Lacey Schwartz grew up in an upper middle-class Jewish family, in a town in upstate New York where almost everyone she knew was white. She assumed that she was, as well. Her recent documentary, Little White Lie, tells the story of how she uncovered the secret of her true racial background. VOA’s Carolyn Weaver has more on the film.
Video

Video Deep Under Antarctic Ice Sheet, Life!

With the end of summer in the Southern hemisphere, the Antarctic research season is over. Scientists from Northern Illinois University are back in their laboratory after a 3-month expedition on the Ross Ice Shelf, the world’s largest floating ice sheet. As VOA’s Rosanne Skirble reports, they hope to find clues to explain the dynamics of the rapidly melting ice and its impact on sea level rise.
Video

Video US-Cuba Normalization Talks Resume Friday

Negotiations aimed at normalizing diplomatic relations between the U.S. and Cuba resume Friday. On the table: lifting a half-century trade embargo and easing banking and travel restrictions. There's opposition in Congress, but some analysts say there may be sufficient political and economic incentives in both nations for a potential breakthrough this year. VOA's Mil Arcega reports.
Video

Video Pakistan's Deadline For SIM Registration Has Cellphone Users Scrambling

Pakistani cell phone users have until midnight Thursday to register their SIM cards, or their service will be cut off. While some privacy experts worry about government intrusion, many Pakistanis are just worried about keeping their phone lines open. VOA Deewa reporter Arshad Muhmand has more from Peshawar.
Video

Video Myanmar Warns Factory Workers to End Strikes

Outside Myanmar's main city Yangon, thousands of workers walked off their jobs earlier this month demanding a doubling of their wages, pay raises after a year and input from labor unions on industrial regulations. Since Friday, the standoff has grown more tense as police moved in to disrupt the sit-ins, resulting in clashes that injured people from both sides. VOA correspondent Steve Herman visited industrial zones which have become a focus of Myanmar's fledgling workers rights movement.
Video

Video Oscar Winners Do More Than Thank the Academy

The Academy Awards presentation is Hollywood’s night to reward the best movies from the previous year. It’s typically a lot of glitter, a lot of thank you’s, a lot of speeches. But many of this year’s speeches carried messages beyond the thank you's. VOA’s Carolyn Presutti takes a look.

All About America

Circumventing Censorship

An Internet Primer for Healthy Web Habits

As surveillance and censoring technologies advance, so, too, do new tools for your computer or mobile device that help protect your privacy and break through Internet censorship.
More