title: Moving to mate: the evolution of separate and combined sexes in multicellular organisms.
abstract: Which conditions favour the evolution of hermaphroditism or separate sexes? One classical hypothesis states that an organism's mode of locomotion (if any) when searching for a mate should influence breeding system evolution. We used published phylogenies to reconstruct evolutionary changes in adult mate-search efficiency and breeding systems among multicellular organisms. Employing maximum-likelihood analyses, we found that changes in adult mate-search efficiency are significantly correlated with changes in breeding system, and this result is robust to uncertainties in the phylogenies. These data provide the first statistical support, across a broad range of taxa, for the hypothesis that breeding systems and mate-search efficiency did not evolve independently. We discuss our results in context with other causal factors, such as inbreeding avoidance and sexual specialization, likely to affect breeding system evolution.
authors: Department of Biology, Portland State University, Portland, OR 97207-0751, USA. eppley@pdx.edu
authors: S M
authors: SM
authors: Eppley
authors: L K
authors: LK
authors: Jesson
mesh_terms: D000818:Animals; D005075:Biological Evolution; D003198:Computer Simulation; D012734:Disorders of Sex Development / Q000235:genetics; D007448:Invertebrates / Q000235:genetics; D008954:Models, Biological; D010802:Phylogeny; D010944:Plants; D012098:Reproduction / Q000235:genetics; D012723:Sex; D012727:Sex Characteristics; D014714:Vertebrates / Q000235:genetics