Meeting Abstract
Within geckos, elaborately integrated toe pads holding highly branched setae confer dynamic attachment on a variety of substrates. While frictional adhesion is considered key to diversification, penetrating and interlocking claws are ancestral and nearly ubiquitous features within lizards. Geckos exhibit multiple attachment character states through claw and pad loss that may reflect different selective regimes, such as a mixed substrate environment favoring the presence of both features. Recent experiments have only scratched the surface of the pad-claw functional interplay but do show texture-dependence (e.g., claws dominant on rough substrate). That geckos also display multiple pad types and degrees of claw reduction calls for a more holistic approach to understand their association and evolutionary significance. How do these features covary, and does phylogeny and/or habitat use drive these patterns? We dissected and imaged the fourth pedal digit of specimens within Gekkonoidea, from which we scored and measured aspects of the pad and claw. After size and phylogenetic correction, we saw little correlation between trait measurements, but PGLS models indicated that pad type predicted some variables, such as more strongly curved claws in leaf-padded species. PhyANOVAs revealed smaller pads in generalist and terrestrial species relative to scansorialists and longer setae in saxicolous geckos. Smaller pads have been noted in more terrestrial anoles and thus may reflect reduced functional demands, but the relationship between setal length and actual performance has yet to be resolved in padded lizards. This project provides important evolutionary and ecological insights into gecko autopodial diversity and perspective for the evolution of complex functional systems.
