Levi Morran, PhD


Levi Morran, PhD
(he/him)

Associate Professor, Department of Biology, Emory College of Arts and Sciences

Lab Website

Graduate Programs

  • Full Member - Population Biology, Ecology, and Evolution

Education

PhD, University of Oregon, 2009
BS, Indiana University, 2004

Contact Information

Email: levi.morran@emory.edu

Phone: 404-727-7092

Address:
O. Wayne Rollins Research Center, Room 1029 1510 Clifton Road NE Atlanta, GA 30322 1940-001-1AC

Adaptation driven by natural selection is a fundamental mechanism of evolutionary change. However, the underlying selective pressures and genetic underpinnings that shape the evolutionary process within and among populations are not always clear. The primary goal of my research program is to identify and characterize factors that either facilitate or constrain adaptive evolution. I seek to determine the influence of such factors on the genetic architecture and evolutionary trajectory of populations. I utilize experimental evolution coupled with microbiology as a means to test evolutionary theory, which allows me to study the adaptive process in real-time at the phenotypic, genotypic, and genomic levels. My current research explores both coevolutionary dynamics and mating system evolution as factors that influence and potentially dictate the role of adaptive evolution in populations.

Coevolution accounts for a significant proportion of the evolutionary change that occurs in nature. My goal is to determine the role that selective pressures derived from reciprocal interspecific interactions play in shaping the genetic composition and evolutionary trajectories of coevolving populations. The nature of these interspecific interactions spans a continuum from highly mutualistic to highly parasitic, and I seek to understand the evolutionary implications of interactions at both ends of the spectrum using several nematode/bacteria systems.

My work on mating system evolution utilizes the nematode Caenorhabditis elegans and is built upon a hypothesis-testing framework that is motivated by evolutionary theory. My goal is to understand the widespread maintenance of outcrossing in nature that seems to defy evolutionary theory. My previous work established two selective pressures, both elevated mutation rates and exposure to novel environments (including pathogens), as conditions that can favor outcrossing over self-fertilization. Additionally, my research demonstrated the ability of coevolving pathogens to favor the evolution and maintenance of outcrossing despite the cost of males. This work further established the Red Queen hypothesis as a plausible explanation for the widespread prevalence of outcrossing in nature. I am now working to understand the underlying genetic change and phenotypic evolution that occurred as result of antagonistic coevolution.

Unconscious Bias Training
Culturally Aware Mentoring (iCAM), National Research Mentoring Network (NRMN)

Milon Barmon

Milon Barmon (he/him)

Population Biology, Ecology, and Evolution

Entrance Year: 2022

Andrew Cameron

Andrew Cameron (he/him)

Population Biology, Ecology, and Evolution

Entrance Year: 2024

Emily Smith

Emily Smith (she/her)

Population Biology, Ecology, and Evolution

Entrance Year: 2021

Topic: Mating System Evolution

Michelle McCauley

Population Biology, Ecology, and Evolution

PhD, 2024

"An Experimental Test of the Pluralistic Approach to the Maintenance of Outcrossing"


Jordan Lewis

Population Biology, Ecology, and Evolution

PhD, 2022

"The influence of evolutionary reciprocity and genetic architecture on the evolution of host defense in Caenorhabditis elegans"


Kayla Stoy

Population Biology, Ecology, and Evolution

PhD, 2022

"The persistence of host-symbiont mutualisms: Investigating the roles of genetic variation, coevolution, and transmission mode"


Amanda (Shurzinske) Smith

Genetics and Molecular Biology

PhD, 2021

"FUNGAL PATHOGEN GENOME STABILITY AND ADAPTIVE POTENTIAL DEPEND ON HOST IMMUNE STATUS AND PATHOGEN PLOIDY"


Kim Hoang

Population Biology, Ecology, and Evolution

PhD, 2019

"ESTABLISHING A NOVEL BENEFICIAL ASSOCIATION USING A NEMATODE-BACTERIUM MODEL THROUGH EXPERIMENTAL EVOLUTION"


P. Signe White

Population Biology, Ecology, and Evolution

PhD, 2019

"THE EVOLUTION OF VIRULENCE IN HETEROGENEOUS HOST POPULATIONS"


Dorian Feistel

Population Biology, Ecology, and Evolution

MS, 2017