Data from: Sexual dimorphism modifies habitat‐associated divergence: evidence from beach and creek breeding sockeye salmon

Studies of parallel or convergent evolution (the repeated, independent
evolution of similar traits in similar habitats) rarely explicitly
quantify the extent of parallelism (i.e., variation in the direction
and/or magnitude of divergence) between the sexes; instead they often
investigate both sexes together or exclude one sex. However, differences
in male and female patterns of divergence could contribute to overall
variation in the extent of parallelism among ecotype pairs, especially in
sexually dimorphic traits. Failing to properly attribute such variation
could lead to underestimates of the importance of environmental variation
in shaping phenotypes. We investigate the extent of parallelism in the
body shape of male and female beach and creek spawning sockeye salmon
(Oncorhynchus nerka) from two lake systems in western Alaska that were
colonized independently after the last ice age. Although both sexes showed
some degree of parallelism, patterns of beach‐creek body shape divergence
vary between the sexes and between lake systems. Phenotypic change vector
analyses revealed highly parallel aspects of divergence between males from
different lake systems (males from beaches had deeper bodies than males
from creeks) but weaker parallelism in females, and high parallelism
between the sexes in one lake system but not the other. Body shape also
had population‐specific components, which were mostly, but not entirely,
explained by environmental variation in the form of creek depth. Our
results highlight the importance of explicitly considering the extent of
parallelism between the sexes, and environmental variation among sites
within habitat types.