Immigration counter-acts local micro-evolution of a major fitness component: Migration-selection balance in free-living song sparrows.

ABSTRACT: Ongoing adaptive evolution, and resulting "evolutionary rescue" of declining populations, requires additive genetic variation in fitness. Such variation can be increased by gene flow resulting from immigration, potentially facilitating evolution. But, gene flow could in fact constrain rather than facilitate local adaptive evolution if immigrants have low additive genetic values for local fitness. Local migration-selection balance and micro-evolutionary stasis could then result. However, key quantitative genetic effects of natural immigration, comprising the degrees to which gene flow increases the total local additive genetic variance yet counteracts local adaptive evolutionary change, have not been explicitly quantified in wild populations. Key implications of gene flow for population and

SUBMITTER: Reid JM 

PROVIDER: S-EPMC7857281 | biostudies-literature | 2021 Feb

REPOSITORIES: biostudies-literature