Data from: The phenotypic determinants of diet variation between divergent lineages of threespine stickleback

Lineages with independent evolutionary histories often differ in both
their morphology and diet. Experimental work has improved our
understanding of the links between the biomechanics of morphological
traits and foraging performance (trait-utility). However, because the
expression of foraging-relevant traits and their utility can be highly
context-specific, it is often unclear how dietary divergence arises from
evolved phenotypic differences. Here, we explore the phenotypic causes of
dietary divergence between two genetically and phenotypically divergent
lineages of threespine stickleback (Gasterosteus aculeatus) with
independent evolutionary histories of freshwater colonization and
adaptation. First, using individuals from a line-cross breeding design, we
conducted 150 common-garden foraging trials with a community of multiple
prey species and performed morphological and behavioural analyses to test
for prey-specific trait-utility. Second, we tested if the traits that
explain variation in foraging performance among all individuals could also
explain the dietary divergence between the lineages. Overall, we found
evidence for the utility of several foraging traits, but these traits did
not explain the observed dietary divergence between the lineages in common
garden. This work suggests that evolved dietary divergence results not
only from differences in morphology but also from divergence in behaviours
that underlie prey capture success in species-rich prey communities.