International Research Fellowship Program: When Does Nature Favor Chaos?: Metapopulation Dynamics, Life History Evolution, and Multi-Level Selection

Fletcher Jeffrey A, Portland OR

Investigators

Abstract

0402136 Fletcher The International Research Fellowship Program enables U.S. scientists and engineers to conduct three to twenty-four months of research abroad. The program's awards provide opportunities for joint research, and the use of unique or complementary facilities, expertise and experimental conditions abroad. This award will support a twenty-two-month research fellowship by Dr. Jeffrey A. Fletcher to work with Dr. Leticia Aviles at University of British Columbia in Vancouver, British Columbia, Canada. This project is about metapopulation dynamics, life history evolution and multilevel selection. The social spiders and malaria parasites are two examples of strongly subdivided metapopulation systems where biased sex ratios and fast rates of local growth may be associated with intrinsic dynamical instability and multiple levels of selection. With such model systems in mind and a combination and empirical and theoretical methods, the PI and host will explore: (1) the factors that allow locally chaotic dynamics to evolve and be evolutionary stable, (2) how different degrees of population subdivision and rates of extinction and recolonization influence multilevel selection on life history traits that affect population dynamics; and (3) how natural selection acting among and within groups partitions changes in brood size and sex ratio to arrive at a particular local population growth rate. These questions are investigated with: (1) an individual-based computer simulation model with coevolving traits for sex ratio and clutch size, and variable degrees of population subdivision; (2) a cross-species study using existing population census time series data as well as existing literature on relevant life history traits and degrees of population subdivision; (3) collaborative empirical studies on various related species of neotropical social spiders. This project is expected to take two years and involve two month-long trips to Latin America. Expected outcomes of this work include: (1) development of sharable software to study the relationship between levels of selection, life history traits, and population dynamics; (2) enhanced understanding of how life history traits influence population dynamics in other highly subdivided populations including endangered species living in highly fragmented environments and parasites living in hosts (e.g. malaria); (3) involvement of undergraduate and graduate students in this project; and (4) sharing findings through guest lectures in classrooms and seminars for audiences of various educational levels.