# Quantitative genetics and population genomics of repeated complex trait evolution

> **NIH NIH R35** · UNIVERSITY OF SOUTH CAROLINA AT COLUMBIA · 2022 · $368,168

## Abstract

PROJECT SUMMARY
Complex phenotypes are suites of adaptive traits that contribute to a shared function. An
important challenge is understanding how such phenotypes evolve and are maintained in
populations. Theory predicts that the evolution of complex traits and their preservation in the
face of homogenizing gene flow will depend on the genetic architecture of trait divergence, the
types and sources of genetic variation, and the presence of reproductive isolating barriers.
However, we lack empirical systems to rigorously test these theoretical expectations. While
investigations into the genetic basis of repeated phenotypic evolution in emerging model taxa
provide an opportunity whether, and how often, evolution proceeds through similar genetic
processes, studies of repeated evolution have often involved comparison of only two or three
lineages, and rarely have studied complex traits. My research group will bridge these gaps by
investigating evolutionary genetics of floral pollination syndrome, a complex adaptation, in the
plant genus Penstemon. In this genus, a novel syndrome phenotype has evolved at least 20
independent times. My group will initiate research directions aimed at systematically quantifying
genetic and genomic features governing the evolution and maintenance of complex trait
diversity, leveraging the exceptional parallelism in Penstemon. We will examine the genetic and
genomic architecture of adaptive divergence using replicate QTL analyses, determine which
elements of complex traits display genetic parallelism, assess whether standing variation or
gene flow act as a source of genetic variation, and examine how complex trait variation is
maintained in recently diverged species using population genomic data. This integrative work
will contribute to the development of a general framework for understanding whether, and
through what mechanisms, phenotypic evolution is constrained by genetic mechanisms. In other
words, such data will illuminate the inherent flexibility and limits of an organism's genome to
adapt to novel environmental challenges.

## Key facts

- **NIH application ID:** 10458041
- **Project number:** 5R35GM142636-02
- **Recipient organization:** UNIVERSITY OF SOUTH CAROLINA AT COLUMBIA
- **Principal Investigator:** Carrie Wessinger
- **Activity code:** R35 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2022
- **Award amount:** $368,168
- **Award type:** 5
- **Project period:** 2021-08-01 → 2026-05-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10458041

## Citation

> US National Institutes of Health, RePORTER application 10458041, Quantitative genetics and population genomics of repeated complex trait evolution (5R35GM142636-02). Retrieved via AI Analytics 2026-05-22 from https://api.ai-analytics.org/grant/nih/10458041. Licensed CC0.

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