Data from: Population genetics and independently replicated evolution of predator-associated burst speed ecophenotypy in mosquitofish

Many species show replicated ecophenotypy due to recurring patterns of
natural selection. Based on the presence or absence of pursuit predators,
at least 17 species of fish repeatedly differentiated in body shape in a
manner that increases burst swimming speed and the likelihood of predator
escape. The predator-associated burst speed (PABS) ecophenotype is
characterized by a small head and trunk and enlarged caudal region.
Mechanisms promoting replicated phenotype-environment association include
selection (without evolution), a single instance of adaptive evolution
followed by biased habitat occupation, repeated instances of local
adaptation, or adaptive phenotypic plasticity. Common garden rearing of
mosquitofish, Gambusia affinis, demonstrated a likely heritable basis for
PABS phenotypy, but it is unknown whether populations are otherwise
genetically distinct or whether replicated ecophenotypy represents a
single or replicated instances of adaptation. To genetically characterize
the populations and test hypotheses of single or multiple adaptations, we
characterized variation in 12 polymorphic DNA microsatellites in the
previously studied G. affinis populations. Populations were genetically
distinct by multilocus analysis, exhibited high allelic diversity, and
were heterozygote deficient, which effects were attributed to G. affinis’s
shoaling nature and habitat patchiness. Genetic and phenotypic distances
among populations were correlated for non-PABS but not PABS morphology.
Multilocus analysis demonstrated ecophenotype polyphyly and scattered
multivariate genetic structure which support only the
replicated-adaptation model. As all of the diverse tests performed
demonstrated lack of congruence between patterns of molecular genetic and
PABS differentiation, it is likely that divergent natural selection drove
multiple instances of adaptive evolution.Many species show replicated
ecophenotypy due to recurring patterns of natural selection. Based on the
presence or absence of pursuit predators, at least 17 species of fish
repeatedly differentiated in body shape in a manner that increases burst
swimming speed and the likelihood of predator escape. The
predator-associated burst speed (PABS) ecophenotype is characterized by a
small head and trunk and enlarged caudal region. Mechanisms promoting
replicated phenotype-environment association include selection (without
evolution), a single instance of adaptive evolution followed by biased
habitat occupation, repeated instances of local adaptation, or adaptive
phenotypic plasticity. Common garden rearing of mosquitofish, Gambusia
affinis, demonstrated a likely heritable basis for PABS phenotypy, but it
is unknown whether populations are otherwise genetically distinct or
whether replicated ecophenotypy represents a single or replicated
instances of adaptation. To genetically characterize the populations and
test hypotheses of single or multiple adaptations, we characterized
variation in 12 polymorphic DNA microsatellites in the previously studied
G. affinis populations. Populations were genetically distinct by
multilocus analysis, exhibited high allelic diversity, and were
heterozygote deficient, which effects were attributed to G. affinis’s
shoaling nature and habitat patchiness. Genetic and phenotypic distances
among populations were correlated for non-PABS but not PABS morphology.
Multilocus analysis demonstrated ecophenotype polyphyly and scattered
multivariate genetic structure which support only the
replicated-adaptation model. As all of the diverse tests performed
demonstrated lack of congruence between patterns of molecular genetic and
PABS differentiation, it is likely that divergent natural selection drove
multiple instances of adaptive evolution.