Adaptive Radiation in Toepad Characteristics in Mainland and Caribbean Anolis Communities


Meeting Abstract

44.2  Monday, Jan. 5  Adaptive Radiation in Toepad Characteristics in Mainland and Caribbean Anolis Communities FRANK, H.K.*; MAHLER, D.L.; REVELL, L.J.; LOSOS, J.B.; Harvard University, Cambridge, MA; Harvard University, Cambridge, MA; Harvard University, Cambridge, MA; Harvard University, Cambridge, MA hkfrank@fas.harvard.edu

Caribbean Anolis lizards are a model system for the study of evolutionary divergence and adaptive radiation as species on the different islands of the Greater Antilles living in similar habitats have converged onto similar morphologies. Toepads, which bear lamellae that allow lizards to adhere to complex surfaces, are crucial in allowing lizards to inhabit different niches. In the Caribbean, toepad width and lamella number show distinct evolutionary patterns that correlate with ecological characteristics. However, comparatively little is known about mainland Anolis species despite the fact that these animals comprise over half of the total radiation of the genus. Based on previously published data, we hypothesized that mainland species will show significantly less adaptive divergence (higher phylogenetic signal) than Caribbean species. We calculate phylogenetic signal (Blomberg’s K) based on measurements of lamella number and toepad width taken from scans of the fore and hindfeet of over 2,131 individuals from 203 species of Anolis. Preliminary results based on a subset of the data support previous findings and indicate extensive adaptive divergence of toepad structure in the Caribbean (K < 1), but suggest toepad evolution in mainland species is significantly more correlated with phylogenetic relationships (Kmainland > KCaribbean). Further studies exploring the ecological and functional differences between mainland and Caribbean anoles that may drive the observed differences are needed.

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