Meeting Abstract
133.3 Monday, Jan. 7 Correlational Selection on Resting Metabolic Rate and Body Mass in the Common Lizard ARTACHO, P*; LE GALLIARD, JF; Univ. Austral de Chile, Valdivia; Univ. Pierre et Marie Curie, Paris paulinaartacho@gmail.com
Phenotypic selection, the differential survival or reproduction of individuals with different phenotypic characters, is widely accepted as the primary cause of adaptive evolution in natural populations. Its impact on evolutionary dynamics has been documented profusely during the last decades for both simple morphological characters and life-history traits. Comparatively, the strength and shape of selection acting on more complex functional properties (e.g. physiological traits), still remain poorly investigated. Further, most current studies of phenotypic selection have been performed by analyzing phenotypic traits separately or in a small subset of functional traits. However, behavior, morphology, physiology and performance traits should evolve in concert and their interactions should affect fitness significantly. This study wished to address these issues by performing a field phenotypic selection experiment on locomotor performance, thermal behavior and energy metabolism using as a model the common lizard, Zootoca vivipara. We captured 200 individuals (males and females of different ages) in field for measuring body mass (Mb), resting metabolic rate (RMR), maximal sprint speed and preferred body temperature at the laboratory. After measurements, animals were released in outdoor enclosures between the end of one reproductive season and the end of the next one, after which they were recaptured and its survival evaluated. The dataset was analyzed with logistic regression which indicated a complex picture with a combination of positive correlational selection between Mb and RMR, and disruptive selection on RMR. In conclusion individuals that showed high Mb and high RMR were promoted by selection, but also individuals that had low RMR. This is one of the few studies that have demonstrated correlational selection on a proxy of energy expenditure.
