June 16 2010

12:00 LSB 2320

James Rosindell
The University of Leeds, UK

Island biogeography, speciation and the neutral theory of biodiversity


The species diversity on islands has fascinated ecologists, geographers and evolutionary biologists for many decades. A seminal contribution to the field was McArthur and Wilson's 1967 "Theory of Island Biogeography", which envisages an equilibrium in diversity, where immigration balances out local extinction. The theory of island biogeography later motivated Hubbell's 2001 "Unified Neutral Theory of Biodiversity and Biogeography" which predicts species abundances as well as species richness. It seems that the unified neutral theory should be useful in island biogeography, but still relatively little work has been done in this direction. Here we explore extensions to the unified neutral theory to make it more suitable as a general model for island biogeography. Allowing for island endemics to exist is an important component and the way that speciation and immigration is modeled turns out to be very important in order to get realistic results. Many existing verbal arguments, observations and predictions exist in island biogeography and remain largely unsupported by any mechanistic model. The neutral model shows many of these predictions involving species abundances, ages and origin as emergent behaviors. We conclude that neutral models can and should be used as null models for island biogeography, but that care needs to be taken in choosing which assumptions should be made besides the neutrality assumption itself.











































































































































































































































































































































































































































































































































































































this is idtest: