The multiple origins of sexual size dimorphism in global amphibians

作者：Daniel Pincheira‐Donoso, Lilly P. Harvey, Florencia Grattarola, Manuel Jara, Sheena C. Cotter, Tom Tregenza, David J. Hodgson · 发表于：Global Ecology and Biogeography · 年份：2020 · DOI：10.1111/geb.13230 · 被引用次数：55 · 研究领域：Amphibian and Reptile Biology、Animal Behavior and Reproduction、Wildlife Ecology and Conservation

Abstract Aim Body size explains most of the variation in fitness within animal populations and is therefore under constant selection from ecological and reproductive pressures, which often promote its evolution in sex‐specific directions, leading to sexual size dimorphism (SSD). Several hypotheses have been proposed to explain the vast diversity of SSD across species. These hypotheses emphasize: (a) the mate competition benefits to larger male size (sexual selection); (b) the benefits of larger female size for fecundity (fecundity selection); (c) the simultaneous benefits of niche divergence for males and females to reduce intersexual competition for ecological resources (natural selection); and (d) the underlying impact of geographical variation in climatic pressures expected to shape large‐scale patterns of SSD in synergy with the above selection pressures (e.g., intensification of fecundity selection as breeding seasons shorten). Based on a new, global‐scale amphibian dataset, we address the shortage of large‐scale, integrative tests of these four hypotheses. Location Global. Time period Extant. Major taxa studied Class Amphibia. Methods Using a > 3,500 species dataset spanning body size, ecological, life‐history, geographical and climatic data, we performed phylogenetic linear models to address the sexual, fecundity, ecological and climatic hypotheses of SSD. Results Evolution of SSD is discordant between anurans and salamanders. Anuran SSD is shaped by climate (male‐b...