Corrigendum: Dimensionality and modularity of adaptive variation: Divergence in threespine stickleback from diverse environments

Populations are subjected to diverse environmental conditions that affect
fitness and induce evolutionary or plastic responses, resulting in
phenotypic divergence among populations. Some authors contend such
divergence is concentrated along a single major axis of trait covariance,
even if that axis does not lead populations directly toward fitness
optimum. Other authors argue that divergence can occur readily along many
phenotype axes at the same time. We use populations of threespine
stickleback (Gasterosteus aculeatus) from 14 lakes with contrasting
ecological conditions to find some resolution along the continuum between
these two extremes. Unlike many previous studies, we included several
functional suites of traits (defensive, swimming, trophic) potentially
subject to different sources of selection. We find that populations
exhibit dimensionality of divergence that is high enough to preclude a
history of constraint along a single axis – both for divergence in
multivariate mean trait values and for the structure of trait covariances.
Dimensionality varied among trait suites and were strongly influenced by
the inclusion of specific traits, and integration of trait suites varied
between populations. We leverage this variation into new insights about
the process of divergence and suggest that similar analyses could increase
understanding of other adaptive radiations.