Abstract
Animal groups exhibit a spectacular diversity in the scaling relationships among different body parts or traits, and between these and overall body size; changes in such allometries among traits is clearly a major pathway by which morphology evolves. However, even with over a century of interest in the evolution of allometry, essentially nothing is known about the mechanisms of change in scaling relationships. Developmental processes must play a central role in maintaining the functional scaling relationships among traits as well as in their evolution. To study both process and pattern in evolution we have initiated an integrative, broad ?evo-devo? research program on allometry. In this project we will quantify allometry across species of Lepidoptera for the particular combinations of traits as examined experimentally in previous artificial selection experiments using the tropical butterfly Bicyclus anynana (i.e. forewing size relative to hindwing size, or forewing size relative to body size). We will also perform a range of genetical, developmental and physiological experiments using developmentally-staged individuals from our selected lines to unravel the underlying mechanisms of evolutionary change, and to explore the bases of observed patterns of bias in the evolution of the allometries in terms of how the individual traits contributed to changes in their scaling relationships. A deeper understanding of the roles of proximate mechanisms in the evolution of such complex phenotypes is needed to build a predictive ?evo-devo? theory of trait evolution that can then be generalized to other organisms. This is the overall goal of our multidisciplinary project.
Netherlands