Meeting Abstract
Understanding how morphology scales with body size is one of the most pervasive topics in evolutionary biology. In the context of static scaling, the extreme products of sexual selection are of particular interest. Ornaments of choice and weapons of battle grow to drastic proportions, and typically scale steeply with body size when viewed across a population. This pattern is widespread, and tests of steep scaling are commonly used to infer a sexual selection function. However, the degree to which patterns of static scaling reflect weapon/ornament evolution and, by extension, the degree to which these patterns provide insight into biological function, remains unclear. Here, we compare a suite of extreme structures (14 signaling, 15 non-signaling) to more typically proportioned ‘reference’ structures within the same organism. We show that steep static scaling relationships are common when structures function as signals of overall quality, but not for comparably extreme structures that function in other contexts. We review the literature surrounding animal signals, discuss our results in the context of sexual selection, signal function, and morphological scaling, and argue that the function of sexually selected signal structures can indeed be inferred from patterns of static scaling.
