Sexual selection forms the structure and dynamics of ecological communities
- Department of Biology, Division of Zoology, University of Oslo, P.O. Box 1050 Blindern, N-0316 Oslo, Norway
The fields of community ecology and evolutionary ecology have in the past, to a large extent, been moving along separate paths. However, occasionally the two fields do meet, as in the article by Doherty et al. (1) in this issue of PNAS, in which the authors interpret new and exciting results obtained through statistical analysis of ecological monitoring data (2) within the framework of sexual selection (3). Through a powerful statistical analysis of data collected by volunteers, the authors are able to show, at a continent-wide scale, that sexual selection is associated with higher local extinction and turnover rates in natural bird communities, which affects biodiversity across the continent (Fig. 1). The insight thus obtained is both novel and highly interesting from an ecological point of view. In addition, the results reported (1) might have important implications for our understanding of the ecological dynamics and evolution of biotic communities, as well as for how we are to best protect threatened species.
Sexual selection accounts for the occurrence of elaborate displays such as the bright plumage color of the male hooded warbler Wilsonia citrina (Upper). The intensity of sexual selection is apparently much weaker in species such as the Canada goose Branta canadensis (Lower), where the sexes have similar plumage colors. In this issue of PNAS, Doherty et al. (1) demonstrate that sexual selection can have dramatic effects on the structure and dynamics of North American bird communities: sexually dichromatic species experience much higher local extinction and turnover rates than monochromatic ones. (Photograph taken by Paul Doherty.)
The article by Doherty et al. (1) uses several advances within the currently very active field of statistical modeling of ecological data (2, 4). The paper specifically addresses the dynamics of communities, through the analysis of extinction and turnover rates estimated from North …
