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Evolution of drift robustness in small populations.

ABSTRACT: Most mutations are deleterious and cause a reduction in population fitness known as the mutational load. In small populations, weakened selection against slightly-deleterious mutations results in an additional fitness reduction. Many studies have established that populations can evolve a reduced mutational load by evolving mutational robustness, but it is uncertain whether small populations can evolve a reduced susceptibility to drift-related fitness declines. Here, using mathematical modeling and digital experimental evolution, we show that small populations do evolve a reduced vulnerability to drift, or 'drift robustness'. We find that, compared to genotypes from large populations, genotypes from small populations have a decreased likelihood of small-effect deleterious mutations, thus causing small-population genotypes to be drift-robust. We further show that drift robustness is not adaptive, but instead arises because small populations can only maintain fitness on drift-robust fitness peaks. These results have implications for genome evolution in organisms with small effective population sizes.

SUBMITTER: LaBar T

PROVIDER: S-EPMC5647343 | biostudies-literature | 2017 Oct

REPOSITORIES: biostudies-literature

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Evolution of drift robustness in small populations.

LaBar Thomas T Adami Christoph C

Nature communications 20171018 1

Most mutations are deleterious and cause a reduction in population fitness known as the mutational load. In small populations, weakened selection against slightly-deleterious mutations results in an additional fitness reduction. Many studies have established that populations can evolve a reduced mutational load by evolving mutational robustness, but it is uncertain whether small populations can evolve a reduced susceptibility to drift-related fitness declines. Here, using mathematical modeling a ...[more]

PMID: 29044114

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Dataset Information

Evolution of drift robustness in small populations.

Publications

Evolution of drift robustness in small populations.

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