Departures from neutrality induced by niche and relative fitness differences
MetadataShow full item record
KeywordNeutral theory; Niche difference; Relative fitness difference; Demographic stochasticity; Species abundance distribution
Breaking the core assumption of ecological equivalence in Hubbell’s “neutral theory of biodiversity” requires a theory of species differences. In one framework for characterizing differences between competing species, non-neutral interactions are said to involve both niche differences, which promote stable coexistence, and relative fitness differences, which promote competitive exclusion. We include both in a stochastic community model in order to determine if relative fitness differences compensate for changes in community structure and dynamics induced by niche differences, possibly explaining neutral theory’s apparent success. We show that species abundance distributions are sensitive to both niche and relative fitness differences, but that certain combinations of differences result in abundance distributions that are indistinguishable from the neutral case. In contrast, the distribution of species’ lifetimes, or the time between speciation and extinction, differs under all combinations of niche and relative fitness differences. The results from our model experiment are inconsistent with the hypothesis of “emergent neutrality” and support instead a hypothesis that relative fitness differences counteract effects of niche differences on distributions of abundance. However, an even more developed theory of interspecific variation appears necessary to explain the diversity and structure of non-neutral communities.
© The Author(s), 2015. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Theoretical Ecology 8 (2015): 449-465, doi:10.1007/s12080-015-0261-0.
The following license files are associated with this item:
Showing items related by title, author, creator and subject.
Species-specific relative ahr1 binding affinities of 2,3,4,7,8-pentachlorodibenzofuran explain avian species differences in its relative potency Farmahin, Reza; Jones, Stephanie P.; Crump, Doug; Hahn, Mark E.; Giesy, John P.; Zwiernik, Matthew J.; Bursian, Steven J.; Kennedy, Sean W. (2013-12)Results of recent studies showed that 2,3,4,7,8-pentachlorodibenzofuran (PeCDF) and 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) are equipotent in domestic chicken (Gallus gallus domesticus) while PeCDF is more potent than ...
Bidirectional incompatibility among divergent Wolbachia and incompatibility level differences among closely related Wolbachia in Nasonia Bordenstein, Seth R.; Werren, John H. (2007-03-07)Most insect groups harbor obligate bacterial symbionts from the alphaproteobacterial genus Wolbachia. These bacteria alter insect reproduction in ways that enhance their cytoplasmic transmission. One of the most common ...
Montgomery, Ellyn T.; Guest, Brian J. (Woods Hole Oceanographic Institution, 1999-02)R/V Seward Johnson cruise 98-07 occurred between October 12 and November 5, 1998. The goal of the cruise was to deploy 30 Salinity Profiling Autonomous Lagrangian Current Explorer (S-PALACE) floats in the tropical Atlantic ...