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The accumulation of reproductive isolation in early stages of divergence supports a role for sexual selection
Author(s) -
Martin M. D.,
Mendelson T. C.
Publication year - 2016
Publication title -
journal of evolutionary biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.289
H-Index - 128
eISSN - 1420-9101
pISSN - 1010-061X
DOI - 10.1111/jeb.12819
Subject(s) - reproductive isolation , biology , ecological speciation , sexual selection , genetic algorithm , selection (genetic algorithm) , isolation (microbiology) , evolutionary biology , ecological selection , ecology , zoology , genetic divergence , divergence (linguistics) , genetic variation , genetics , demography , gene flow , population , genetic diversity , linguistics , philosophy , artificial intelligence , sociology , computer science , microbiology and biotechnology , gene
Models of speciation by sexual selection propose that male–female coevolution leads to the rapid evolution of behavioural reproductive isolation. Here, we compare the strength of behavioural isolation to ecological isolation, gametic incompatibility and hybrid inviability in a group of dichromatic stream fishes. In addition, we examine whether any of these individual barriers, or a combined measure of total isolation, is predicted by body shape differences, male colour differences, environmental differences or genetic distance. Behavioural isolation reaches the highest values of any barrier and is significantly greater than ecological isolation. No individual reproductive barrier is associated with any of the predictor variables. However, marginally significant relationships between male colour and body shape differences with ecological and behavioural isolation are discussed. Differences in male colour and body shape predict total reproductive isolation between species; hierarchical partitioning of these two variables' effects suggests a stronger role for male colour differences. Together, these results suggest an important role for divergent sexual selection in darter speciation but raise new questions about the mechanisms of sexual selection at play and the role of male nuptial ornaments.