Featured Research

from universities, journals, and other organizations

Interacting mutations promote diversity

Date:
June 28, 2012
Source:
Max-Planck-Gesellschaft
Summary:
Frequency-dependent selection fosters the diversity of populations but does not always increase the average fitness of the population.

Frequency-dependent selection fosters the diversity of populations but does not always increase the average fitness of the population.

Genetic diversity arises through the interplay of mutation, selection and genetic drift. In most scientific models, mutants have a fitness value which remains constant throughout. Based on this value, they compete with other types in the population and either die out or become established. However, evolutionary game theory considers constant fitness values to be a special case. It holds that the fitness of a mutation also depends on the frequency of the mutation. Scientists from the Max Planck Institute for Evolutionary Biology in Plön and the University of British Columbia in Vancouver developed a model to address the scenario of mutations being frequency-dependent but having random fitness parameters. The results demonstrate that the dynamics that arise in random mutants increase the genetic diversity within a population. Fitness, though, may even decline.

Population geneticists generally study mutations with constant fitness values. However, frequency-dependent selection is a recurrent theme in evolution: it enables the evolution of new species without geographical separation (sympatric speciation) or a relatively rapid change in the immune system of a population.

A mutation may be advantageous for low frequencies, for instance, but the fitness of the mutant decreases with rising frequency. A reverse trend in the fitness value is also conceivable. "Our computer model combines aspects of population genetics and evolutionary game theory in order to obtain a new perspective on genetic evolution," says Arne Traulsen from the Max Planck Institute for Evolutionary Biology. Whereas mutations have a random yet fixed fitness value in many mathematical models, this new model also enables a change in random fitness values with the frequency of the different types.

The results of the simulations show that frequency-dependent selection leads to higher genetic diversity within a population of individuals even though diversity per se is not favoured. The interaction of different mutations and the emergence of new mutants support the development of dynamic diversity in the population. One mutant does not always need to replace all other mutations or the original population. "It is possible for different mutations to exist in parallel such that a new mutant does not to completely replace the residents," says Weini Huang, lead author of the study. What is particularly interesting is the fact that diversity in this model remains naturally limited.

Fitness, on the other hand, does not necessarily rise with frequency-dependent selection in contrast to constant selection. By way of example, a mutation may arise within cells which halts the production of substances that are passed on to other cells. This can initially be advantageous; however, if it reaches fixation, the average fitness of the cell population declines. Advantageous mutations can thereby be lost and deleterious ones become established.


Story Source:

The above story is based on materials provided by Max-Planck-Gesellschaft. Note: Materials may be edited for content and length.


Journal Reference:

  1. Weini Huang, Bernhard Haubold, Christoph Hauert, Arne Traulsen. Emergence of stable polymorphisms driven by evolutionary games between mutants. Nature Communications, 2012; 3: 919 DOI: 10.1038/ncomms1930

Cite This Page:

Max-Planck-Gesellschaft. "Interacting mutations promote diversity." ScienceDaily. ScienceDaily, 28 June 2012. <www.sciencedaily.com/releases/2012/06/120628130651.htm>.
Max-Planck-Gesellschaft. (2012, June 28). Interacting mutations promote diversity. ScienceDaily. Retrieved July 24, 2014 from www.sciencedaily.com/releases/2012/06/120628130651.htm
Max-Planck-Gesellschaft. "Interacting mutations promote diversity." ScienceDaily. www.sciencedaily.com/releases/2012/06/120628130651.htm (accessed July 24, 2014).

Share This




More Plants & Animals News

Thursday, July 24, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Stone Fruit Listeria Scare Causes Sweeping Recall

Stone Fruit Listeria Scare Causes Sweeping Recall

Newsy (July 22, 2014) — The Wawona Packing Company has issued a voluntary recall on the stone fruit it distributes due to a possible Listeria outbreak. Video provided by Newsy
Powered by NewsLook.com
Michigan Plant's Goal: Flower and Die

Michigan Plant's Goal: Flower and Die

AP (July 22, 2014) — An 80-year-old agave plant, which is blooming for the first and only time at a University of Michigan conservatory, will die when it's done (July 22) Video provided by AP
Powered by NewsLook.com
Huge Schizophrenia Study Finds Dozens Of New Genetic Causes

Huge Schizophrenia Study Finds Dozens Of New Genetic Causes

Newsy (July 22, 2014) — The 83 new genetic markers could open dozens of new avenues for schizophrenia treatment research. Video provided by Newsy
Powered by NewsLook.com
CDC Head Concerned About a Post-Antibiotic Era

CDC Head Concerned About a Post-Antibiotic Era

AP (July 22, 2014) — Sounding alarms about the growing threat of antibiotic resistance, CDC Director Tom Frieden warned Tuesday if the global community does not confront the problem soon, the world will be living in a devastating post-antibiotic era. (July 22) Video provided by AP
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:
from the past week

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