Is it possible to characterize the phenotypic space from the relationship among the elements of a body plan? A systemic analysis in the lizard Uta stansburiana

Abstract

Quantitative relationships among the elements of the body plan of Uta stansburiana were analyzed to evaluate their influence on the structure and limits of its phenotypic space. A methodology based on conceiving organisms as systems was developed. The relations among the elements of the body plan are described by a system of simultaneous equations (SES) of the type xi = mxj + b, where xi and xj are morphometric variables, and m and b are constants. This system was employed to simulate the phenotypic variation of U. stansburiana and to characterize its phenotypic space. The results indicate that the structure and limits of the phenotypic space of a taxon are emergent properties of the system that constitutes the body plan. These properties can be considered internal constraints, which act jointly with natural selection generating discontinuous phenotypic spaces. In this paper we propose a methodology that defines and analyzes with a systemic approach the phenotypic space of a taxon. This may be useful for proposing and testing hypothesis related with the causal factors of this space.