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GENETIC MODELS OF ADAPTATION AND GENE FLOW IN PERIPHERAL POPULATIONS
Author(s) -
GarcíaRamos Gisela,
Kirkpatrick Mark
Publication year - 1997
Publication title -
evolution
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.84
H-Index - 199
eISSN - 1558-5646
pISSN - 0014-3820
DOI - 10.1111/j.1558-5646.1997.tb02384.x
Subject(s) - biology , gene flow , local adaptation , evolutionary biology , population , selection (genetic algorithm) , genetic drift , adaptation (eye) , genetic divergence , range (aeronautics) , trait , genetic algorithm , divergence (linguistics) , ecology , gene , genetics , genetic variation , genetic diversity , linguistics , philosophy , materials science , demography , artificial intelligence , neuroscience , sociology , computer science , composite material , programming language
We investigate the interplay between gene flow and adaptation in peripheral populations of a widespread species. Models are developed for the evolution of a quantitative trait under clinally varying selection in a species whose density decreases from the center of the range to its periphery. Two major results emerge. First, gene flow from populations at the range center can be a strong force that inhibits peripheral populations from evolving to their local ecological optima. As a result, peripheral populations experience persistent directional selection. Second, response to local selection pressures can cause rapid and substantial evolution when a peripheral population is isolated from gene flow. The amount of evolutionary change depends on gene flow, selection, the ecological gradient, and the trait's heritability. Rapid divergence can also occur between the two halves of a formerly continuous population that is divided by a vicariant event. A general conclusion is that disruption of gene flow can cause evolutionary divergence, perhaps leading to speciation, in the absence of contributions from random genetic drift.