Morranlab:Research

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Research interests

We are broadly interested in factors that either facilitate or constrain adaptive evolution. Currently we are exploring the roles that mating systems and coevolutionary dynamics play in adaptive evolution.

We often utilize experimental evolution to directly test hypotheses and determine the manner in which evolution proceeds by characterizing both the phenotypic and genotypic changes that occur in evolving populations.

• MATING SYSTEM EVOLUTION

Mating systems dictate the manner in which genes are transmitted from parent to offspring, and therefore determine the level of genetic variation within and between lineages of a population. Mating systems are a key component of reproduction, and reproduction is a basic requirement in biology. Despite this ubiquitous importance, many different mating systems exist in nature. We are interested in the selective pressures that favor specific mating systems, the genetic consequences of different mating systems, and their overall role in shaping the evolutionary trajectory of a population and/or lineage over time.

We generally work with the nematode Caenorhabditis elegans to study mating systems because this species utilizes two different mating strategies, outcrossing and self-fertilization.

• COEVOLUTIONARY DYNAMICS

Coevolution accounts for a significant proportion of the evolutionary change that occurs in nature. This is quite reasonable because most, if not all, species live as members of communities composed of many species. As a result of interactions between members in a community, many species utilize not only their own genome, but also the genome of other species to facilitate survival and reproduction in context of mutualistic interactions. Conversely, antagonistic interactions between species are capable of driving rapid evolutionary change between interacting species. Thus intergenomic interactions, resulting from both mutualistic and antagonistic coevolution, play a major role in shaping the evolutionary trajectory of many species. We are interested in learning how coevolutionary interactions affect each interacting species, and also understanding the role that mating systems play in determining the outcome of coevolutionary interactions.

We work with C. elegans and the bacterial pathogen, Serratia marcescens, to study antagonistic coevolution. Though we are branching out into other systems and we are always excited to work with new species that will allow us to answer new questions. We also work with the nematode Steinernema carpocapsae and its bacterial symbiont, Xenorhabdus nematophila, to study mutualistic coevolution.

Collaborators

• Farrah Bashey-Visser, Indiana University
• Jaap deRoode, Emory University
• Nicole Gerardo, Emory University
• Heidi Goodrich-Blair, University of Wisconsin-Madison
• Matt Hahn, Indiana University
• Kayla King, University of Oxford
• Curt Lively, Indiana University
• Patrick McGrath, Georgia Tech
• Patrick Phillips, University of Oregon