Sagehen Creek Field Station

02 Oct, 11 AM - 04 Oct, 02 AM

The genus Mimulus has become a model system in evolutionary ecology for the study of speciation and adaptation. The study of population genetic structure across species' ranges is an important first step for understanding mechanisms of population divergence and cohesion across the landscape. The purpose of this study is to examine the population genetic structure of species with similar distributions but different levels of local adaptation. We have chosen two pairs of closely related and interfertile species pairs within the genus Mimulus: M. cardinalis - M. lewisii and M. guttatus - M. tilingii. These species pairs exhibit similar patterns of parapatry, with M. cardinalis and M. guttatus occurring from low - mid elevations and M. lewisii and M. tilingii occurring from mid - high elevations. The guttatus-tilingii pair is notable for the high levels of genetic and morphological polymorphism found within populations as well as for striking local adapation across many environmental gradients. In contrast, the cardinalis-lewisii pair exhibits much lower genetic and phenotypic diversity and no observable local adaptation within species with respect to altitude. Therefore, comparisons of the population genetic structure of these species across altitude and latitude gradients will enable us to investigate how the balance between divergent natural selection and homogenizing gene flow results in different levels of local adaptation in these species. We propose to sample 0.2 g leaf tissue (approximately 1 young leaf) from 10 individuals from each of 30 populations across California. These species are common, locally abundant, and large perennial herbs. The small amount of tissue removed will not adversely affect their survival or reproduction. Leaf tissue will be brought to the Angert Lab at Colorado State University for DNA extraction and PCR amplification of 50 genetic loci with known sequence polymorphisms (single nucleotide polymorphisms, or "SNPs"). This study will be among the first to use powerful SNP markers for a multi-locus investigation of population genetic structure. Patterns of SNP polymorphisms within and among populations can reveal important biological parameters such as genetic diversity, historical population size, and gene flow. Compared across species, these parameters can contribute to our understanding of the factors that promote or hinder adaptation and speciation. This project requires no environmental manipulations. We propose only to collect a small amount of leaf tissue (0.2 g, or about the size of one young leaf) from 10 individuals of each species found on the reserve. These large perennial herb species are locally abundant and widespread, and the small amount of tissue removed will not adversely affect individuals or populations.

Visit #16308 @Sagehen Creek Field Station

Approved

Under Project # 10257 | Research

Comparative population genetic structure of Mimulus species

faculty - Colorado State University

Reservation Members(s)

Amy Angert Oct 2 - 4, 2008 (3 days)

Reserve Resources(s) | Create Invoice

Burnside Cabin (Upper Camp) 1 Oct 2 - 4, 2008