NSF Postdoctoral Fellowship in Biology

This action funds an NSF Plant Genome Postdoctoral Research Fellowship in Biology for FY 2022. The fellowship supports a research and training plan in a host laboratory for the Fellow who also presents a plan to broaden participation in biology. The title of the research and training plan for this fellowship to Dr.

Benjamin Stone is "Genomic predictability of ecological speciation: insights from replicate hybrid zones". The host institution for the fellowship is the University of South Carolina and the sponsoring scientist is Dr. Carolyn Wessinger.

Identifying the evolutionary mechanisms underlying patterns of genetic differentiation between species as they diverge is a primary goal of speciation genomics. It is important to understand the genomics of speciation in a variety of biological systems, because doing so allows us to compare evolutionary processes across taxonomic groups and assess the degree to which evolution may be repeatable and predictable across the tree of life.

However, our understanding these processes is currently limited, as much of our knowledge stems from controlled experimental crosses in genetic model systems. This project uses whole-genome sequence data to identify genomic features of adaptive divergence and reproductive isolation across natural hybrid zones of non-model plants in the genus Penstemon.

The data and insights generated through this project have applications in evolutionary biology, agriculture management, and conservation biology, and include the development of a comparative framework which addresses the predictability of genomic features of adaptive trait divergence and speciation. Training objectives include the development and integration of new skills in the quantification and analysis of phenotypic and genomic variation in natural populations, as well as the development of mentoring and project management skills through the mentorship of undergraduate researchers and the completion of mentoring training programs.

Broader impacts include broadening diversity in STEM by utilizing well-established programs at the host institution that target undergraduate researchers from historically underrepresented groups in STEM. This includes the recruitment of undergraduate mentees to collaborate on the work, and building mentee research expertise through supervised independent projects.

Adaptive radiation, or the proliferation of ecologically diverse species within a lineage, is a key mechanism of biological diversification. Despite the importance of this process, our understanding of the genomic underpinnings of adaptive trait divergence and reproductive isolation is limited, especially in non-model systems. This limitation inhibits our ability to determine the degree to which genomic processes of species differentiation are predictable and generalizable across the tree of life.

This project integrates complementary methodologies (admixture mapping and genomic cline analysis) across natural replicate hybrid zones in a non-model adaptive radiation to understand whether the genomic basis of adaptive trait divergence involves predictable features. These goals are pursued in two primary Objectives. Objective 1 integrates phenotypic and genomic data to map QTLs for adaptive floral divergence in separate hybrid zones involving secondary contact between distinct species pairs.

Objective 2 identifies genomic regions associated with barriers to gene flow in hybrid zones and determines whether these regions correspond to identified floral QTLs. This project generates novel molecular (population-level whole-genome resequencing data) and phenotypic data for focal taxa in the genus Penstemon, and integrates complementary methodologies across these data sets to contribute to a more phylogenetically diverse perspective of the genetic underpinnings of ecological adaptations and their role in reproductive isolation.

Phenotypic data and scripts for data analysis will be available on the Dryad Digital Repository. Genome assemblies will be archived in the NCBI Genome Assembly repository, and raw reads will be deposited in the NCBI Sequence Read Archive.

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.