When and how can Group Composition be locally adapted? A test with Social Spiders.

University Of Pittsburgh, Pittsburgh PA

Investigators

Abstract

Whether or how societies are able to sense poor-performing group compositions and respond to them adaptively across different environments remains unknown. Group composition, or the relative representation of individuals with different traits, is often thought to be a major determinant of social group organization and success. Some groups naturally exhibit compositions which help them flourish and others express mixtures that yield their demise. A tractable society (social spiders) will be used to assess how variation in group composition influences the growth, reproductive rate, and extinction risk of entire societies. Societies of different mixtures will be generated and deployed at different field sites, and the success of these societies will be tracked over time. Additionally, the shifts in societies' composition will be monitored over time, in order to see whether societies are able to sense their ailing compositions and shift them adaptively. The proposed work will further our understanding of how societies, as collective entities, evolve and adjust adaptively to current challenges. This has implications in fields ranging from medicine, to agriculture, and conservation. Virtually every aspect of biology is interested in understanding the drivers of extinction: farmers want to eradicate pests and preserve cultivars; epidemiologists want to drive world pathogens to extinction; while conservation biologists hope to eradicate invasive pest species while preserving dwindling natives. Understanding how groups of organisms (like social spiders) sense and respond to pending extinction risk under normal circumstances might help us predict the factors that can accelerate, slow, or circumvent extinction in other taxa where rigorous experiments are not generally possible. Finally, numerous undergraduates and K-12 students will be involved with elements of the project's implementation as well as the dissemination of the findings. Each year more than a dozen high school teachers help to collect, analyze, and disseminate the findings of these studies, and undergraduates from the University of Pittsburgh gain on-site training on field ecologists and the scientific method.