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

At Khmer Rouge Court, Long-Awaited Verdict Approaches

First phase of trial, which is coming to an end, has focused on forced exodus of Phnom Penh in 1975 - and now many are hopeful justice will be served More

Video When Fighting Eases, Gazans Line Up at Bakeries

When there is a lull in the conflict, residents who have been hunkered down in their apartments rush out to stock up on food and other necessities More

Video Information War Rages Alongside Real One in Ukraine

Downing of Malaysian airliner, allegations of cross-border shelling move information war in war-torn country to a new level 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.
Information War Rages Alongside Real One in Ukrainei
X
Al Pessin
July 31, 2014 8:13 PM
The downing of the Malaysian airliner two weeks ago, and allegations that Russians are shelling Ukrainian troops across the border, have moved the information war swirling around the Ukrainian conflict to a new level. VOA's Al Pessin reports from Kyiv.
Video

Video Information War Rages Alongside Real One in Ukraine

The downing of the Malaysian airliner two weeks ago, and allegations that Russians are shelling Ukrainian troops across the border, have moved the information war swirling around the Ukrainian conflict to a new level. VOA's Al Pessin reports from Kyiv.
Video

Video When Fighting Eases, Gazans Line Up at Bakeries

When there is a lull in the conflict in Gaza, residents who have been hunkered down in their apartments rush out to stock up on food and other necessities. Probably the most important destination is the local bakery. VOA’s Scott Bobb reports from Gaza City.
Video

Video US-Funded Program Offers Honduran Children Alternative to Illegal Immigration

President Obama and Central American leaders recently agreed to come up with a plan to address poverty and crime in the region that is fueling the surge of young migrants trying to illegally enter the United States. VOA’s Brian Padden looks at one such program in Honduras - funded in part by the United States - which gives street kids not only food and safety but a chance for a better life without, crossing the border.
Video

Video 'Fab Lab' Igniting Revolution in Kenya

The University of Nairobi’s Science and Technology Park is banking on 3-D prototyping to spark a manufacturing revolution in the country. Lenny Ruvaga has more for from Nairobi's so-called “FabLab” for VOA.
Video

Video Gazans in Shelled School Sought Shelter

Israel's air and ground assault against Hamas-led fighters in Gaza has forced many Palestinians to flee their homes, seeking safety. But safe places are hard to find, as VOA’s Scott Bobb reports from Jabaliya.
Video

Video Rapid Spread of Ebola in West Africa Prompts Global Alert

Across West Africa, health officials are struggling to keep up with what the World Health Organization describes as the worst ebola outbreak on record. The virus has killed hundreds of people this year. U.S. President Barack Obama and other world leaders are watching the developments closely as they weigh what actions, if any, are needed to help contain the disease.
Video

Video Michelle Obama: Young Africans Need to Embrace Women's Rights

U.S. first lady Michelle Obama urged some of Africa's best and brightest to advocate for women's rights in their home countries. As VOA's Pam Dockins explains, Obama spoke to some 500 participants of the Young African Leaders Initiative, a six-week U.S.-based training and development program.
Video

Video Immigrant Influx on Texas Border Heats Up Political Debate

Immigrants from Central America continue to cross the U.S.-Mexico border in south Texas, seeking asylum in the United States, as officials grapple with ways to deal with the problem and provide shelter for thousands of minors among the illegal border crossers. As VOA's Greg Flakus reports from Houston, the issue is complicated by internal U.S. politics and U.S. relations with the troubled nations that immigrants are fleeing.
Video

Video Study: Latino Students Most Segregated in California

Even though legal school segregation ended in the United States 60 years ago, one study finds segregation still occurs in the U.S. based on income and race. The University of California Los Angeles Civil Rights Project finds that students in California are more segregated by race than ever before, especially Latinos. Elizabeth Lee reports for VOA from Los Angeles.

AppleAndroid