Data from: Non-uniform evolutionary response of gecko eye size to changes in diel activity patterns

Geckos feature a large range of eye sizes, but what drives this phenotypic
diversity is currently unknown. Earlier studies point towards diel
activity patterns (DAP) and locomotory mode, but phylogenetic comparative
studies in support of the proposed adaptive mode of eye evolution are
lacking. Here we test the hypothesis of DAP as the driver of eye size
evolution with a dataset on 99 species of gecko. Results from phylogenetic
generalized least square analysis (PGLS) and multivariate model-fitting
reveal smaller eyes in diurnal geckos consistent with different phenotypic
optima. However, Bayesian analyses of selective regime shifts demonstrate
that only 2 of 9 transitions from nocturnal to diurnal activity are
coupled with decreases in eye size, and 2 other regime shifts are not
associated with DAP transitions. This non-uniform evolutionary response
suggests that eye size is not the only functionally relevant variable.
Evolutionary adaptations may therefore include different combinations of
several traits (e.g., photoreceptors), all with the same functional
outcome. Our results further demonstrate that DAP only partially explains
eye size diversity in geckos. As open habitats favor the evolution of
large eyes while obstructed habitats favor small eyes, the degree of
habitat clutter emerges as another potential axis of eye diversification.