My Research


Broadly, my research focuses on using a population genetics approach to elucidate evolutionary processes of wildlife populations.

I also have an interest in programming and statistics, and frequently use these tools in my research.

Current Position:

I am currently a postdoctoral scholar in the Evolution, Ecology and Organismal Biology department at the Ohio State University. For my postdoctoral research I am characterizing patterns of local adaptation using genotype-environment associations in a panmictic population of Douglas squirrels that occur in an ecological gradient. Further, I am also using genomic methods to explore how the environment and host genetics shape the gut microbiome in two tree squirrel species across the Pacific Northwest.

Previous Positions:


Ph.D. Biology 2014-2019

Advisor: Emily K Latch

University of Wisconsin-Milwaukee


M.S. Biology 2011-2014

Advisor: Emily K Latch

University of Wisconsin-Milwaukee


B.S. Ecology and Conservation Biology 2005-2009

Advisors: John Byers and Janet Rachlow

University of Idaho


Research Projects:


Unraveling Plague Ecology through Pathogen, Vector, and Host Genetics

Plague is a flea-borne, zoonotic disease caused by the bacterium Yersinia pestis. Since its introduction to North America >100 years ago, it has spread to native rodents, thereby establishing a sylvatic cycle. Plague is typically detected during outbreaks, referred to as epizootics, in prairie dog colonies. The disease sweeps through colonies, moving from group to group, until nearly the entire colony has been killed. When no susceptible hosts remain, the outbreak dies down. However, it is not well understood how plague is maintained or how it is transmitted between prairie dog colonies. Prairie dogs are likely poor transmitters of plague since they live in highly structured social groups and do not regularly travel between colonies. Some have hypothesized that Y. pestis is maintained in resistant hosts, such as small mammals, in an enzootic cycle. These resistant hosts may transmit plague-infected fleas among prairie dog colonies. The aim of my PhD study is to investigate the role that small mammals play in plague ecology using tools from the field of population genetics to examine relationships between rodents, fleas, and Y. pestis. By examining the genetic structure of Y. pestis, fleas, and mammalian hosts, we can begin to clarify how plague is maintained and dispersed as well as which hosts are most likely to be involved. Plague has caused major ecological disruptions in grassland ecosystems, extirpating whole colonies of prairie dogs and contributing to the decline and near extinction of several species [e.g. the endangered Utah prairie dog (Cynomys parvidens) and black-footed ferret (Mustela nigripes)]. Thus, understanding the role of small mammals and prairie dogs in maintaining Y. pestis in prairie ecosystems is an important step in designing targeted management strategies to reduce the incidence of plague.


Evaluation of Alternative Management Strategies for the Maintenance of Genetic Variation in Wildlife Populations

Bison (Bison bison bison) once numbered in the millions and roamed across much of the lower 48 states. By the late 1800s, overhunting had reduced the population to around 1,000 individuals. Strong efforts to establish managed herds have resulted in a steady bison population increase. Currently, six herds are maintained by the U.S. Fish and Wildlife Service (FWS) at National Wildlife Refuges (NWRs) and are intensively managed through annual culling to keep herd size at targeted levels. Although various criteria have historically been used to select individuals for culling, the FWS currently employs an allele frequency based strategy that we have generalized as the ‘mean allele frequency (MAF)’ strategy, with the goal of keeping at least a few individuals that represent each element of genetic variation. We developed an individual-based model to compare the ‘MAF’ and ‘random removal of young’ culling strategies to a ‘pedigree-based’ strategy based on the field of zoo biology to cull individuals based on kinship. The model was parameterized using existing long-term demographic and genetic data from the herd located in the Fort Niobrara NWR, Nebraska. Additionally, a separate panel of loci was generated to determine the effects of genetic-based culling on non-target loci that are not considered during management decisions. We found the pedigree-based strategy performed the best at maximizing the retention of genome-wide variation.

Find Me On:

ResearchGate

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@rachael_giglio

Contact Me At:

giglio.20[at]osu.edu