IRFP: Eco-Evolutionary Dynamics of Allee Effects and their Mitigating Adaptations

Shaw Allison K, Princeton NJ

Investigators

Abstract

The International Research Fellowship Program enables U.S. scientists and engineers to conduct nine 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-four-month research fellowship by Dr. Allison K. Shaw to work with Dr. Hanna Kokko at the Australian National University (Canberra, Australia) and with Dr. Michael Neubert at the Woods Hole Oceanographic Institution (Massachusetts). An Allee effect describes a positive relationship between an individual's fitness and the number of its conspecifics, the most common example being an individual's increased chance of finding mates at higher population density. It may be tempting to predict that any adaptation that allows an individual to overcome an Allee effect should have been selected for, since Allee effects negatively impact an individual's fitness at low density. However, this may not be the case if periods of low density were rare during a species' evolutionary history. Furthermore, some types of adaptations (including dispersal) may actually exacerbate Allee effects in a population that has been artificially reduced to a low density. Before we can predict the dynamics of low-density populations, we need to develop a solid understanding of how Allee effects and their mitigating adaptations interact. The two broad objectives of this research are 1) to build a theoretical framework integrating Allee effects and counter adaptations in an eco-evolutionary context, and 2) to apply the findings to predict dynamics in the specific example of invasive species. The proposed research will contribute fundamentally to our understanding of the dynamics governing populations at low density, which has potential applications in the control of invasive pest species, management of fisheries, and protection of endangered species. This research will also foster valuable international collaboration between the PI and research groups at the Australian National University, other institutions within Australia, and the Woods Hole Oceanographic Institution.