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Natural Selection On Body Size Is Mediated By Multiple Interacting Factors: A Comparison Of Beetle Populations Varying Naturally And Experimentally In Body Size, Angela R. Amarillo-Suárez, R Craig Stillwell, Charles W. Fox

Entomology Faculty Publications

Body size varies considerably among species and among populations within species, exhibiting many repeatable patterns. However, which sources of selection generate geographic patterns, and which components of fitness mediate evolution of body size, are not well understood. For many animals, resource quality and intraspecific competition may mediate selection on body size producing large-scale geographic patterns. In two sequential experiments, we examine how variation in larval competition and resource quality (seed size) affects the fitness consequences of variation in body size in a scramble-competing seed-feeding beetle, Stator limbatus. Specifically, we compared fitness components among three natural populations of S. limbatus …