NSF PRFB FY23: Investigating the genomic consequences of hybridization in the Mimulus guttatus complex

This action funds an NSF Postdoctoral Research Fellowship in Biology for FY 2023, Integrative Research Investigating the Rules of Life Governing Interactions Between Genomes, Environment, and Phenotypes. The fellowship supports the research and training of the fellow that will contribute to the area of Rules of Life in innovative ways. Speciation, the process by which new species evolve, is a fundamental process of evolution that must be studied by exploring the relationships between different groups of organisms. This is often done with a focus on factors that keep groups separated, known as isolating barriers. Research on isolating barriers is often approached through laboratory experiments or surveys of natural variation. This project will unite these approaches to investigate the progression of speciation in a group of monkeyflowers that are known to have rapidly evolved such barriers—in particular, the inability to create healthy seeds when crossed. Genomic investigations of monkeyflower plants from regions where two species meet and produce progeny will be combined with greenhouse crosses to study naturally occurring variation and its consequences. This work will also allow them to make direct connections between barrier phenotypes and the flow of genetic information between two young species. The fellow will use accessions from 5 replicated hybrid zones to genomically dissect the dynamics of introgression between recently diverged Mimiulus guttatus and M. decorus. Patterns of ancestry will be used to identify the rate, timing, and directionality of gene flow. Next, by assessing ancestry correlation among sites in the genome (i.e. patterns of ancestry disequilibrium), the fellow will identify putative incompatibility alleles. Lastly, the fellow will resurrect inbred lines derived from the originally sequenced plants to assess the phenotypes associated with putative incompatibility. The fellow will also mentor undergraduate researchers and provide workshops for graduate students on essential computational research skills. The fellow will also contribute to the public understanding of speciation by developing educational modules that aim to explain speciation research through gameplay. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.