Data from: Disentangling the role of phenotypic plasticity and genetic divergence in contemporary ecotype formation during a biological invasion

The occurrence of contemporary ecotype formation through adaptive
divergence of populations within the range of an invasive species
typically requires standing genetic variation but can be facilitated by
phenotypic plasticity. The relative contributions of both of these to
adaptive trait differentiation have rarely been simultaneously quantified
in recently diverging vertebrate populations. Here we study a case of
intraspecific divergence into distinct lake and stream ecotypes of
threespine stickleback that evolved in the past 140 years within the
invasive range in Switzerland. Using a controlled laboratory experiment
with full-sib crosses and treatments mimicking a key feature of ecotypic
niche divergence, we test if the phenotypic divergence that we observe in
the wild results from phenotypic plasticity or divergent genetic
predisposition. Our experimental groups show qualitatively similar
phenotypic divergence as those observed among wild adults. The relative
contribution of plasticity and divergent genetic predisposition differs
among the traits studied, with traits related to the biomechanics of
feeding showing a stronger genetic predisposition, whereas traits related
to locomotion are mainly plastic. These results implicate that phenotypic
plasticity and standing genetic variation interacted during contemporary
ecotype formation in this case.