Connecting Community Ecology to Macroecology: Size and Diversity Relationships
Compiling both extinct and extant datasets of mammals, current work examines the macroecological patterns of mammal body size. To do so, I create body size distributions through time, and use mathematical models to connect the macroecological patterns to underlying mechanisms from both the community ecology and evolution literature. In collaboration with Aaron Clauset, we examine patterns in ancient horses (Equidae), whales (cetaceans), primates, and terrestrial mammals.
We find that the evolution of mammalian body sizes within sub-clades tends to follow a similar pattern, with an initial expansion primarily into larger body sizes. Then, many sub-clades, regardless of underlying environmental conditions exhibit a relatively stable right-skewed distribution, where the majority of species are relatively small but a few species are orders of magnitude larger than the mean body size observed. Using a system of partial differential equations coupled with simulation models, we are exploring the underlying mechanisms creating this pattern as well as special cases where this general pattern breaks down.