Meeting Abstract

P2.59  Saturday, Jan. 5  Stepwise Flight Reduction Evolved Along Ecological Gradient ZENG, Y*; TANG, J; SINGHAL, S; GONZALES, C; RAHIM, F; NAING, G; AZIZ, A; DUDLEY, R; Univ. of California, Berkeley; Univ. of California, Berkeley; Univ. of California, Berkeley; Univ. of California, Berkeley; Universiti Kebangsaan Malaysia; Univ. of California, Berkeley; Universiti Kebangsaan Malaysia; Univ. of California, Berkeley dreavoniz@berkeley.edu

Progressive wing reduction associated with altitudinal gradient is found in different populations of a single species of stick insect native to Malay Peninsula. We used integrative approaches to investigate the functional consequence, ecological correlates and evolutionary process of this scenario. Morphometric analysis showed a disproportional reduction of wing size and flight musculature, in addition to overall body size reduction towards higher altitudes. Using high-speed filming, motion reconstruction and mechanical models, we discovered that different sized wings serve distinctive aerodynamic functions, leading to various flight performances with different adaptive significance. The morphological and functional transitions of wings are correlated with the gradient of several environmental factors, as revealed by our ecological niche modeling based on distribution of each flight morph. Furthermore, our phylogenetic analyses based on molecular data suggested a stepwise model of wing reduction during diversification toward high altitudes.