Data from: Phenotypic rate and state are decoupled in response to river-to-lake transitions in cichlid fishes

Geographic access to isolated ecosystems is an important catalyst of
adaptive radiation. Cichlid fishes repeatedly colonized rift, crater, and
volcanic lakes from surrounding rivers. We test the “lake effect” on the
phenotypic rate and state across 253 cichlid species. The rate of
evolution was consistently higher (~10-fold) in lakes, and consistent
across different dimensions of the phenotype. Rate shifts tended to occur
coincident with or immediately following river-to-lake transitions,
generally resulting in 2- to 5-fold faster rates than in the founding
riverine lineage. By contrast, river- and lake-dwelling cichlids exhibit
considerable overlap in phenotypes, generally with less disparity in
lakes, but often different evolutionary optima. Taken together, these
results suggest that lake radiations rapidly expand into niches largely
already represented by ancestral riverine lineages, albeit in different
frequencies. Lakes may provide ecological opportunity via ecological
release (e.g., from predators/competitors), but need not be coupled with
access to novel ecological niches.