Dissertation Research: Comparative Analyses of Life History Evolution in Variable Environments: Cole's Paradox Revisited

University Of Arizona, Tucson AZ

Investigators

Abstract

Venable 0105145 The researchers are studying the annual vs. perennial habit as alternative strategies for persistence in variable environments in a group of related plants native to the arid western United States. They will be using DNA sequence data to infer the ancestor-descendant relationships in the Section Anogra of the genus Oenothera (Onagraceae). They will test the association of the annual habit with aridity in the context of this hypothesis of relationships. In addition, they will use demographic studies of an annual species and a closely related perennial species to test for patterns of survival and fecundity predicted to favor the annual vs. perennial habit. The combination of large-scale (phylogenetic) and small-scale (demographic) comparative studies will allow the researchers to examine both the pattern of evolutionary change and specific mechanisms driving this change. It has long been suggested that the transition from the perennial to annual habit is an important pathway of diversification and adaptation in arid lands. In this study of the selective forces driving changes in habit, the researchers will further the understanding of the drivers of biotic diversity in arid lands, and the means by which plants persist in variable environments in general.