Some plant and animal species are rare while others are widespread but all species occupy a limited number of areas. This leads to the question of what prevents a species from expanding its range by adapting to conditions at and beyond current range margins. The aim of this research is to test the hypothesis that range limits arise because genetic variation in ecologically important traits is lower at range edges than at the center of a species? range. To address this hypothesis, the investigators will combine artificial selection experiments that quantify genetic variation in key traits for populations from the center and edges of a species? range, with field estimates of the strength of natural selection on those traits at the range center and edges of the scarlet monkeyflower.
The proposed research addresses the broader issue of understanding the processes that may constrain adaptation in populations. Populations at the edges of species? geographic distributions may be particularly important to the persistence of species in the face of global change. Consequently, investigations of whether populations at the peripheries of species? geographic ranges can adapt to marginal environments are crucial to understanding how ranges may shift in response to environmental change. This is important information for wildlife managers and conservation biologists. In addition, this research will provide many opportunities for undergraduates to obtain research experience in field ecology, greenhouse experiments, and data analysis and interpretation.
