TY - JOUR
T1 - Genetic differentiation and selection against migrants in evolutionarily replicated extreme environments
AU - Plath, Martin
AU - Pfenninger, Markus
AU - Lerp, Hannes
AU - Riesch, Rüdiger
AU - Eschenbrenner, Christoph
AU - Slattery, Patrick A.
AU - Bierbach, David
AU - Herrmann, Nina
AU - Schulte, Matthias
AU - Arias-Rodriguez, Lenin
AU - Rimber Indy, Jeane
AU - Passow, Courtney
AU - Tobler, Michael
PY - 2013/9
Y1 - 2013/9
N2 - We investigated mechanisms of reproductive isolation in livebearing fishes (genus Poecilia) inhabiting sulfidic and nonsulfidic habitats in three replicate river drainages. Although sulfide spring fish convergently evolved divergent phenotypes, it was unclear if mechanisms of reproductive isolation also evolved convergently. Using microsatellites, we found strongly reduced gene flow between adjacent populations from different habitat types, suggesting that local adaptation to sulfidic habitats repeatedly caused the emergence of reproductive isolation. Reciprocal translocation experiments indicate strong selection against immigrants into sulfidic waters, but also variation among drainages in the strength of selection against immigrants into nonsulfidic waters. Mate choice experiments revealed the evolution of assortative mating preferences in females from nonsulfidic but not from sulfidic habitats. The inferred strength of sexual selection against immigrants (RIs) was negatively correlated with the strength of natural selection (RIm), a pattern that could be attributed to reinforcement, whereby natural selection strengthens behavioral isolation due to reduced hybrid fitness. Overall, reproductive isolation and genetic differentiation appear to be replicated and direct consequences of local adaptation to sulfide spring environments, but the relative contributions of different mechanisms of reproductive isolation vary across these evolutionarily independent replicates, highlighting both convergent and nonconvergent evolutionary trajectories of populations in each drainage.
AB - We investigated mechanisms of reproductive isolation in livebearing fishes (genus Poecilia) inhabiting sulfidic and nonsulfidic habitats in three replicate river drainages. Although sulfide spring fish convergently evolved divergent phenotypes, it was unclear if mechanisms of reproductive isolation also evolved convergently. Using microsatellites, we found strongly reduced gene flow between adjacent populations from different habitat types, suggesting that local adaptation to sulfidic habitats repeatedly caused the emergence of reproductive isolation. Reciprocal translocation experiments indicate strong selection against immigrants into sulfidic waters, but also variation among drainages in the strength of selection against immigrants into nonsulfidic waters. Mate choice experiments revealed the evolution of assortative mating preferences in females from nonsulfidic but not from sulfidic habitats. The inferred strength of sexual selection against immigrants (RIs) was negatively correlated with the strength of natural selection (RIm), a pattern that could be attributed to reinforcement, whereby natural selection strengthens behavioral isolation due to reduced hybrid fitness. Overall, reproductive isolation and genetic differentiation appear to be replicated and direct consequences of local adaptation to sulfide spring environments, but the relative contributions of different mechanisms of reproductive isolation vary across these evolutionarily independent replicates, highlighting both convergent and nonconvergent evolutionary trajectories of populations in each drainage.
KW - Ecological speciation
KW - Isolation-by-adaptation
KW - Local adaptation
KW - Poecilia mexicana
KW - Reinforcement
KW - Sexual isolation
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U2 - 10.1111/evo.12133
DO - 10.1111/evo.12133
M3 - Article
C2 - 24033173
AN - SCOPUS:84883560575
SN - 0014-3820
VL - 67
SP - 2647
EP - 2661
JO - Evolution
JF - Evolution
IS - 9
ER -