Featured Research

from universities, journals, and other organizations

How organisms can tolerate mutations, yet adapt to environmental change

Date:
January 25, 2010
Source:
University of Pennsylvania
Summary:
Biologists studying the processes of evolution appear to have resolved a longstanding conundrum: how can organisms be robust against the effects of mutations yet simultaneously adaptable when the environment changes?

A pea growing over two weeks. New research suggests that an optimal level of robustness maintains the phenotype in one environment but also allows adaptation to environmental change.
Credit: iStockphoto/Lachlan Currie

Biologists at the University of Pennsylvania studying the processes of evolution appear to have resolved a longstanding conundrum: How can organisms be robust against the effects of mutations yet simultaneously adaptable when the environment changes?

Related Articles


The short answer, according to University of Pennsylvania biologist Joshua B. Plotkin, is that these two requirements are often not contradictory and that an optimal level of robustness maintains the phenotype in one environment but also allows adaptation to environmental change.

Using an original mathematical model, researchers demonstrated that mutational robustness can either impede or facilitate adaptation depending on the population size, the mutation rate and a measure of the reproductive capabilities of a variety of genotypes, called the fitness landscape. The results provide a quantitative understanding of the relationship between robustness and evolvability, clarify a significant ambiguity in evolutionary theory and should help illuminate outstanding problems in molecular and experimental evolution, evolutionary development and protein engineering.

The key insight behind this counterintuitive finding is that neutral mutations can set the stage for future, beneficial adaptation. Specifically, researchers found that more robust populations are faster to adapt when the effects of neutral and beneficial mutations are intertwined. Neutral mutations do not impact the phenotype, but they may influence the effects of subsequent mutations in beneficial ways.

To quantify this idea, the study's authors created a general mathematical model of gene interactions and their effects on an organism's phenotype. When the researchers analyzed the model, they found that populations with intermediate levels of robustness were the fastest to adapt to novel environments. These adaptable populations balanced genetic diversity and the rate of phenotypically penetrant mutations to optimally explore the range of possible phenotypes.

The researchers also used computer simulations to check their result under many alternative versions of the basic model. Although there is not yet sufficient data to test these theoretical results in nature, the authors simulated the evolution of RNA molecules, confirming that their theoretical results could predict the rate of adaptation.

"Biologists have long wondered how can organisms be robust and also adaptable," said Plotkin, assistant professor in the Department of Biology in Penn's School of Arts and Sciences. "After all, robust things don't change, so how can an organism be robust against mutation but also be prepared to adapt when the environment changes? It has always seemed like an enigma."

Robustness is a measure of how genetic mutations affect an organism's phenotype, or the set of physical traits, behaviors and features shaped by evolution. It would seem to be the opposite of evolvability, preventing a population from adapting to environmental change. In a robust individual, mutations are mostly neutral, meaning they have little effect on the phenotype. Since adaptation requires mutations with beneficial phenotypic effects, robust populations seem to be at a disadvantage. The Penn-led research team has demonstrated that this intuition is sometimes wrong. 

The study, appearing in the current issue of the journal Nature, was conducted by Jeremy A. Draghi, Todd L. Parsons and Plotkin from Penn's Department of Biology and Gόnter P. Wagner of the Department of Ecology and Evolutionary Biology at Yale University.

The study was funded by the Burroughs Wellcome Fund, the David and Lucile Packard Foundation, the James S. McDonnell Foundation, the Alfred P. Sloan Foundation, the Defense Advanced Research Projects Agency, the John Templeton Foundation, the National Institute of Allergy and Infectious Diseases and the Perinatology Research Branch of the National Institutes of Health.


Story Source:

The above story is based on materials provided by University of Pennsylvania. Note: Materials may be edited for content and length.


Journal Reference:

  1. Draghi et al. Mutational robustness can facilitate adaptation. Nature, 2010; 463 (7279): 353 DOI: 10.1038/nature08694

Cite This Page:

University of Pennsylvania. "How organisms can tolerate mutations, yet adapt to environmental change." ScienceDaily. ScienceDaily, 25 January 2010. <www.sciencedaily.com/releases/2010/01/100120131203.htm>.
University of Pennsylvania. (2010, January 25). How organisms can tolerate mutations, yet adapt to environmental change. ScienceDaily. Retrieved October 31, 2014 from www.sciencedaily.com/releases/2010/01/100120131203.htm
University of Pennsylvania. "How organisms can tolerate mutations, yet adapt to environmental change." ScienceDaily. www.sciencedaily.com/releases/2010/01/100120131203.htm (accessed October 31, 2014).

Share This



More Plants & Animals News

Friday, October 31, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Watch Baby Goose Survive A 400-Foot Cliff Dive

Watch Baby Goose Survive A 400-Foot Cliff Dive

Buzz60 (Oct. 31, 2014) — For its nature series Life Story, the BBC profiled the barnacle goose, whose chicks must make a daredevil 400-foot cliff dive from their nests to find food. Jen Markham has the astonishing video. Video provided by Buzz60
Powered by NewsLook.com
World's Salamanders At Risk From Flesh-Eating Fungus

World's Salamanders At Risk From Flesh-Eating Fungus

Newsy (Oct. 31, 2014) — The import of salamanders around the globe is thought to be contributing to the spread of a deadly fungus. Video provided by Newsy
Powered by NewsLook.com
Alcoholic Drinks In The E.U. Could Get Calorie Labels

Alcoholic Drinks In The E.U. Could Get Calorie Labels

Newsy (Oct. 31, 2014) — A health group in the United Kingdom has called for mandatory calorie labels on alcoholic beverages in the European Union. Video provided by Newsy
Powered by NewsLook.com
Malaria Threat in Liberia as Fight Against Ebola Rages

Malaria Threat in Liberia as Fight Against Ebola Rages

AFP (Oct. 31, 2014) — Focus on treating the Ebola epidemic in Liberia means that treatment for malaria, itself a killer, is hard to come by. MSF are now undertaking the mass distribution of antimalarials in Monrovia. Duration: 00:38 Video provided by AFP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:

Strange & Offbeat Stories

 

Plants & Animals

Earth & Climate

Fossils & Ruins

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins