Impact of epistasis and pleiotropy on evolutionary adaptation.
Proc Biol Sci
; 279(1727): 247-56, 2012 Jan 22.
Article
in En
| MEDLINE
| ID: mdl-21697174
ABSTRACT
Evolutionary adaptation is often likened to climbing a hill or peak. While this process is simple for fitness landscapes where mutations are independent, the interaction between mutations (epistasis) as well as mutations at loci that affect more than one trait (pleiotropy) are crucial in complex and realistic fitness landscapes. We investigate the impact of epistasis and pleiotropy on adaptive evolution by studying the evolution of a population of asexual haploid organisms (haplotypes) in a model of N interacting loci, where each locus interacts with K other loci. We use a quantitative measure of the magnitude of epistatic interactions between substitutions, and find that it is an increasing function of K. When haplotypes adapt at high mutation rates, more epistatic pairs of substitutions are observed on the line of descent than expected. The highest fitness is attained in landscapes with an intermediate amount of ruggedness that balance the higher fitness potential of interacting genes with their concomitant decreased evolvability. Our findings imply that the synergism between loci that interact epistatically is crucial for evolving genetic modules with high fitness, while too much ruggedness stalls the adaptive process.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Adaptation, Physiological
/
Epistasis, Genetic
/
Biological Evolution
/
Genetic Pleiotropy
/
Models, Genetic
Type of study:
Prognostic_studies
Language:
En
Journal:
Proc Biol Sci
Journal subject:
BIOLOGIA
Year:
2012
Type:
Article
Affiliation country:
United States