Meeting Abstract
Evolutionary innovations, adaptive traits that allow species access to a new niche, are thought to promote diversification in clades that possess them. Pharyngognathy, an extensive series of modifications to the pharyngeal jaws, has been suggested to facilitate diversification by allowing access to novel trophic niches via functional decoupling of prey capture with the oral jaws and prey processing with the pharyngeal jaws. Pharyngognathy has been proposed as a major driver of ecological and species diversity in iconic fish families like cichlids (Cichlidae), wrasses (Labridae), and damselfishes (Pomacentridae). However, the effects of pharyngognathy on diversification have not been tested using modern phylogenetic comparative methods. We generated a time calibrated megaphylogeny of over 10,000 species of acanthomorph fishes with 119 fossil constraints. We used hidden state speciation and extinction models to assess the macroevolutionary impact of pharyngognathy on acanthomorph diversification. Our results strongly support state-independent diversification models, suggesting that pharyngognath taxa do not exhibit higher diversification rates relative to non-pharyngognaths. This is also consistent with results from nonparametric approaches. We discuss possible reasons for why pharyngognaths do not have elevated diversification rates relative to non-pharyngognaths and highlight how pharyngognathy may promote ecological diversity without promoting diversification rate.
