Research
The Stoy lab research focuses on developing an understanding of the coevolutionary dynamics underlying the persistence and stability of mutualism. How does genetic variation arise in mutualisms and what are the consequences? How do community dynamics alter pairwise evolutionary trajectories? How are mutualisms stabilized in rapidly changing environments? How does organismal integration evolve?
Stoy Lab Research Overview
Our lab aims to advnace understanding of the evolutionary genetics and coevolutionary dynamics underlying mutualism stability. We use natural systems, including interactions between Coreid insects and bacterial Caballeronia symbionts. We also leverage experimental evolution and synthetic biology using Saccharomyces ceresivisae. Using this multi-faceted approach, we use an evolutionary genetics framework to address oustanding questions in the field of mutualism, such as....
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Are horizontally transmitted symbiotic mutualisms characterized by network structure?
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Does community-level coevolution shape the evolutionary trajectories of horizontally transmitted symbiotic mutualisms?
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What is the distribution and intensity of coevolutionary interactions within communities?
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How does genetic variation arise in mutualistic interactions and what are the eco-evolutionary consequences?
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What mechanisms underlie the evolution of organismal integration for interspecific mutualims?
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Dr. Stoy's Current Research: NSF Postdoctoral Research Fellow
Georgia Institute of Technology
Ongoing Projects
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1) How does pairwise vs. diffuse coevolution alter the evolutionary trajectory of mutualism?
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Much of our understanding of coevolution comes from empirical work and theory evaluating how pairs of species reciprocally evolve in response to one another. However, these pairwise trajectories are likely altered by the range of interactions experienced within species-rich communities. Increasingly, empirical evidence from mutualisms in nature suggest these community-level interactions play an important role. New theory also suggests that community level coevolution and the indirect effects species have on one another alter the evolutionary trajectories of pairwise interactions and stabilize communities. By pairing experimental evolution with a model system of Saccharomyces cerevisiae strains obligately dependent on one another for amino acid cross-feeding, Dr. Stoy is evaluating the eco-evolutionary consequences of coevolutionary interactions involving multiple partners. Specifically, she is testing how pairwise vs. diffuse coevolution alters the evolutionary trajectories of mutualism.
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The Stoy Lab will continue to use this system and experimental evolution to gain an understanding of how multi-partner interactions alter the evolutionary trajectories of mutualistic partners.
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Plant and animal hosts often acquire microbial symbionts from their environments through horizontal transmission. This transmission mode is predicted to be costly for the maintenance of mutualism: symbiont transmission does not depend on host fitness, which potentially favors exploitative symbiont traits. How do these mutualisms persist? Does transmission mode alter the direction of symbiont evolution?
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Dr. Stoy addressed these questions using field based analysis, population genetics, and experimental evolution. Leveraging interactions between three Coreid insects (Anasa tristis, Anasa andresii, and Anasa scorbutica) with their bacterial Caballeronia symbionts, she demonstrated that pairwise coevolution does not play a dominant role in the maintenance of these horizontally transmitted mutualisms. Using experimental evolution of an A. tristis commensal symbiont, Serratia marcescens, she also demonstrated that, contrary to expectations, tightly coupling symbiont evolution to the host can favor the evolution of antagonism.
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The Stoy Lab will continue to evaluate coevolution in this system to gain an understanding of how host-symbiont mutualisms persist.
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Dr. Stoy's Dissertation Research: NSF Graduate Research Fellow
Emory University