Meeting Abstract

S4.4  Monday, Jan. 5  Arthropod Aloft: The Origins and Functional Diversification of Insect Flight DUDLEY, R.*; YANOVIAK, S.P.; Univ. of California, Berkeley; Univ. of Arkansas, Little Rock wings@berkeley.edu

The evolution of wings in the late Paleozoic was the essential innovation underlying subsequent hexapod radiations in the terrestrial biosphere. Although the insect analog of Archaeopteryx has yet to be unearthed, recent demonstrations of directed aerial descent in arboreal arthropods have suggested new evolutionary trajectories for the origins and functional utility of protowings. Phylogenetic studies of ancestrally wingless hexapods indicate that aerodynamic control and maneuverability precede the origin of wings proper. A major feature of subsequent pterygote evolution has been historical change in body size; most of modern insect diversity is associated with body lengths less than 5 mm. Repeated bouts of miniaturization have been enabled by acquisition of asynchronous flight muscle and concomitantly elevated wingbeat frequencies during flight. Ordinal-level patterns of wing transformation for non-aerodynamic purposes have similarly been enabled by the high flapping frequencies of the remaining wing pair, an effect most clearly evidenced by the elytra of Coleoptera and the halteres of Diptera. Major features of insect morphological evolution thus derive indirectly from biomechanical adaptations of the flight apparatus.