Meeting Abstract

104.1  Wednesday, Jan. 7  Alternate pathways in the evolution of body elongation, locomotor performance and kinematics in two clades of lizards. BERGMANN, P.J.*; IRSCHICK, D.J.; University of Arizona; University of Massachusetts Amherst pjbergma@email.arizona.edu

Variation in body shape is associated with variation in function in many animals. Body elongation and limb reduction has evolved repeatedly, frequently and to varying degrees in all major clades of vertebrates. However, phylogenetically-informed studies of locomotion and functional morphology in animals ranging from elongate to stocky are lacking, as is a consideration of the evolution of stockiness as a corollary of elongation. We study the evolution of body shape in lizards of the genus Lerista and the phrynosomatines, and relate these different body shapes to locomotor kinematics, performance and habitat selection. We show that Lerista evolve an elongate body shape through changes in different body parts from those involved in the evolution of stockiness in the phrynosomatines. The former lengthen their bodies and shorten their limbs, while the latter broaden their heads and bodies while shortening their bodies and limbs. In general, species with relatively longer limbs increase their velocity by taking longer, quicker strides. The two clades adopt different locomotor strategies that are related to their body shapes. Namely, more elongate Lerista rely on axial bending to move quickly, while the phrynosomatines rely on changes to their limb kinematics to achieve faster locomotion. However, locomotion in unaffected by different substrates, and differently shaped species do not select different substrate habitats. Evolution of these lizards follows multiple pathways, and species with different body shapes can exploit a similar range of habitats through modulation of their locomotor kinematics.