Untangling intra-and interspecific effects on body size clines reveals divergent processes structuring convergent patterns in Anolis lizards

Abstract

Bergmann’s rule—the tendency for body size to increase in colder environments—remains controversial today, despite 150 years of research. Considerable debate has revolved around whether the rule applies within or among species. However, this debate has generally not considered that clade-level relationships are caused by both intra- and interspecific effects. In this article, we implement a novel approach that allows for the separation of intra- and interspecific components of trait-environment relationships. We apply this approach to body size clines in two Caribbean clades of Anolis lizards and discover that their similar body size gradients are constructed in very different ways.