One of the most important characteristics of organisms is their body size -- influencing all physiological processes, life history traits and, ultimately, each of the fundamental processes affecting the diversity and geography of life (immigration, evolution and extinction). Despite its fundamental and pervasive importance, body size varies tremendously among as well as within species. This variation, however, is far from random, exhibiting ecological, geographic and temporal trends that are so general and intriguing that they are termed ecogeographic "rules" of nature (e.g., Bergmann's rule, the island rule and Cope's rule). The investigators will conduct empirical research to develop an integrative theory that will provide a single conceptual construct in which to understand patterns of body size variation across space and time; patterns that are typically viewed as unrelated phenomena. The international and integrative research program the investigators have developed combines theoretical, experimental and comparative approaches across a range of disparate, but strategically selected species and over a broad range of time scales (from the recent and historic periods through the Pliocene), thus allowing them to explore the generality, antiquity and causality of geographic variation in this fundamental feature of life. The principal approach in this project will be to compare body sizes of museum specimens to test for predicted geographic and ecological trends among three focal groups of mammals: 1) mammals inhabiting paleo-islands during the Pliocene and Pleistocene; 2) extant, native mammals inhabiting islands across the globe, and 3) mammals introduced onto islands by Polynesians and by Europeans during the past 2000 years.
This research will provide an integrative understanding of the factors influencing one of life's most fundamental characteristics -- body size, and its variation over space and time. Given that body size influences all physiological, behavioral and ecological characteristics of organisms, these studies will provide important information on the capacities of animals to adapt to environmental challenges including climate change and modification of native landscapes. The products of the fully funded research will include development of international partnerships between research labs in Europe, New Zealand and Hawaii, web access to all scientific data, mentoring of a Ph.D. level graduate research assistant and undergraduate assistants, development of an undergraduate field course in Biogeography, Evolution and Conservation of Insular Biotas, partnership with natural history museums to create an exhibit on The Evolution of Body Size on Islands, and consultations with conservation organizations to assist them in developing effective strategies for conserving not just diversity per se, but also a fundamental aspect of the natural character of native species -- their body size.
