Meeting Abstract

18.4  Friday, Jan. 4  BEYOND BLACK AND WHITE: COMPARATIVE ECOMORPHOLOGY IN THREE RAPIDLY EVOLVING LIZARD SPECIES AT WHITE SANDS DES ROCHES, S.*; TORRESDAL, J.; MORGAN, T.; BRINKMEYER, M.; HARMON, L.J.; ROSENBLUM, E.B.; University of Idaho; University of Idaho; University of Idaho; University of Idaho; University of Idaho; University of California, Berkeley simone.desroches@gmail.com

Determining which traits enable organisms to colonize and persist in new environments is crucial to understanding adaptation and ecological speciation. Selection can simultaneously act on morphology and behaviour to influence performance. We investigated ecomorphological change during adaptation and incipient ecological speciation for three lizard species in New Mexico that have white and dark forms on White Sands and the surrounding Chihuahuan Desert, respectively. For each species, we compared morphology, startle response behaviour (to a simulated predator), and sprint speed performance (on white sand or dark soil substrate) between colour forms. In all species, the two colour forms exhibited differences in morphology (e.g. body size, limb length) and startle response (on matched and mismatched substrates). Sprint speed also differed between forms on alternate substrates. Although not related to morphological differences between forms, speed was influenced by startle response on alternate substrates in two species: individuals that sprinted immediately when stimulated achieved a faster maximum. Our results demonstrate a relationship between performance and behaviour in White Sands lizards and their dark soil counterparts suggesting that differences in behavioural response across populations may be important during ecological speciation. More generally, our results demonstrate the importance of examining the effect of both morphology and behaviour on performance.