The explosion of interest in the neutral theory of biodiversity, with the publication of Hubbell’s book in 2001, has reinvigorated the study of patterns of commonness and rarity, a topic that has been studied by ecologists since the seminal work of researchers such as Motomura, Fisher, MacArthur, and Preston nearly a century ago. A major challenge to understanding what drives such patterns in nature is that different mechanisms can give rise to very similar, or in some cases identical, predictions. To improve our ability to use species abundance patterns to critically evaluate biodiversity theory and identify the mechanisms that drive commonness and rarity in nature, we work in two broad areas:
Although alternative “metacommunity” models often predict very similar shapes for species abundance distributions, they typically differ more strikingly in at least some other predictions – changes in the shape of species-abundance distributions with spatial scale, spatial patterns of occupancy, community similarity, overall metacommunity biodiversity, etc. Steve Hubbell once wrote that “a hallmark of good theory is to fail in interesting and informative ways.” By testing whether alternative models for commonness and rarity can successfully, simultaneously explain multiple ecological patterns, we learn more about what processes are, and are not, well-characterized by existing biodiversity theory.
To some extent, the idea that species-abundance distributions do not contain sufficient information to distinguish between alternative models has arisen because researchers choose to conduct tests that are inappropriate, or have low statistical power. In some cases, model fits to data are pronounced “good” even when problems can be seen from simple visual inspection of the model fit. By developing new approaches to fitting and testing species abundance models (including fitting models in ways that facilitate the simultaneous testing of model fits against multiple response variables), we increase our power to discriminate between alternative models, and to quantify how and how much models depart from real patterns in nature.
Connolly, S. R., T. P. Hughes, D. R. Bellwood, and R. H. Karlson. 2005. Community structure of corals and reef fishes at multiple scales. Science 309: 1363-1365.
Dornelas, M. A., S. R. Connolly, and T. P. Hughes. 2006. Coral reef diversity refutes the neutral theory of biodiversity. Nature 440: 80-82.
Dornelas, M., and S. R. Connolly. 2008. Multiple modes in a coral species abundance distribution. Ecology Letters 11: 1008–1016.
Connolly, S. R., M. Dornelas, D. R. Bellwood, and T. P. Hughes. 2009. Testing species-abundance models: a new bootstrap approach applied to Indo-Pacific coral reefs. Ecology 90: 3138-3149.
Karlson, R.H., S.R. Connolly, and T.P. Hughes. 2011. Spatial variance in abundance and occupancy of corals across broad geographical scales. Ecology 92: 1282-1291.
Bode, M, S.R. Connolly, and J.M. Pandolfi. Species differences drive non-neutral structure in Pleistocene coral communities. American Naturalist, in press. Accepted 9 March 2012.