+1 Recommend
0 collections
      • Record: found
      • Abstract: found
      • Article: found
      Is Open Access

      Sexual selection explains Rensch's rule of allometry for sexual size dimorphism


      Read this article at

          There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.


          In 1950, Rensch first described that in groups of related species, sexual size dimorphism is more pronounced in larger species. This widespread and fundamental allometric relationship is now commonly referred to as ‘Rensch's rule’. However, despite numerous recent studies, we still do not have a general explanation for this allometry. Here we report that patterns of allometry in over 5300 bird species demonstrate that Rensch's rule is driven by a correlated evolutionary change in females to directional sexual selection on males. First, in detailed multivariate analysis, the strength of sexual selection was, by far, the strongest predictor of allometry. This was found to be the case even after controlling for numerous potential confounding factors, such as overall size, degree of ornamentation, phylogenetic history and the range and degree of size dimorphism. Second, in groups where sexual selection is stronger in females, allometry consistently goes in the opposite direction to Rensch's rule. Taken together, these results provide the first clear solution to the long-standing evolutionary problem of allometry for sexual size dimorphism: sexual selection causes size dimorphism to correlate with species size.

          Related collections

          Most cited references47

          • Record: found
          • Abstract: not found
          • Article: not found

          Sexual Dimorphism, Sexual Selection, and Adaptation in Polygenic Characters

            • Record: found
            • Abstract: not found
            • Article: not found

            ALLOMETRY FOR SEXUAL SIZE DIMORPHISM:Pattern and Process in the Coevolution of Body Size in Males and Females

              • Record: found
              • Abstract: found
              • Article: not found

              Prevalence of different modes of parental care in birds.

              Estimates of the incidence of major classes of parental care by birds are drawn from classical studies that preceded both the publication of a massive secondary literature and the revolution driven by molecular approaches to avian phylogeny. Here, I review this literature in the light of new phylogenetic hypotheses and estimate the prevalence of six distinct modes of care: use of geothermal heat to incubate eggs, brood parasitism, male only care, female only care, biparental care and cooperative breeding. Female only care and cooperative breeding are more common than has previously been recognized, occurring in 8 and 9% of species, respectively. Biparental care by a pair-bonded male and female is the most common pattern of care but at 81% of species, the pattern is less common than once believed. I identify several problems with existing hypotheses for the evolution of parental care and highlight a number of poorly understood contrasts which, once resolved, should help elucidate avian social evolution.

                Author and article information

                Proc Biol Sci
                Proceedings of the Royal Society B: Biological Sciences
                The Royal Society (London )
                18 September 2007
                07 December 2007
                : 274
                : 1628
                : 2971-2979
                [1 ]Department of Behavioural Ecology and Evolutionary Genetics, Max Planck Institute for Ornithology PO Box 1564, 82305 Starnberg (Seewiesen), Germany
                [2 ]Department of Biological Sciences, University of Wisconsin-Milwaukee PO Box 413, Milwaukee, WI 53201, USA
                [3 ]Estación Biológica de Doñana, Consejo Superior de Investigaciones Científicas Apartado 1056, 41013 Sevilla, Spain
                [4 ]Bergen Museum, Department of Natural History, University of Bergen Muséplass 3, 5007 Bergen, Norway
                [5 ]Department of Biology and Biochemistry, University of Bath Bath BA2 7AY, UK
                Author notes
                [* ]Author for correspondence ( dale@ 123456orn.mpg.de )

                These authors contributed in equal part to this study.

                Copyright © 2007 The Royal Society

                This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

                : 31 July 2007
                : 5 September 2007
                : 5 September 2007
                Research Article

                Life sciences
                allometry,sexual size dimorphism,sexual selection,mating system,birds,rensch's rule
                Life sciences
                allometry, sexual size dimorphism, sexual selection, mating system, birds, rensch's rule


                Comment on this article