Rebecca Tarvin, Professor

Closed (1) Experimental evolution of toxic flies

Closed. This professor is continuing with Spring 2021 apprentices on this project; no new apprentices needed for Fall 2021.

Evolutionary transitions underlying phenotypic change are difficult to study because they often occur over millions of years. However, the fruit fly has a short generation time and a small genome that is well annotated and cheap to sequence. We are using a large-scale experimental evolution approach to evolve toxin-sequestering fruit flies with a combination of toxin exposure and parasitism as selective agents. Evolutionary changes in the fruit fly genome, transcriptome, and physiology will generate a model of how chemical defense arises that will inform other studies in poison frogs and other organisms.



Undergraduate students are being recruited to help run experimental assays (e.g. metabolic rate, larval competition, LC50, reproductive output, bang-sensitivity, etc) and to help with the day-to-day maintenance of fly and wasp strains. Students will have the opportunity to gain training in evolutionary biology and genetics, experimental design, fly husbandry, and running physiological assays. An overall expected outcome is to develop scientific skills and help prepare for a career in science. Sufficiently motivated and talented students may be able to develop independent thesis projects within the context of this research.

Day-to-day supervisor for this project: Tyler Douglas, Graduate Student

Qualifications: Competitive applicants will have several or all of the following qualities: excellent organization skills, a knack for creative approaches to solving problems, a positive attitude. Experience working with flies is helpful but not necessary. **We will likely recruit for two URAP positions in Fall 2021**

Weekly Hours: 9-11 hrs

Related website: https://www.tarvinlab.org/research

Closed (2) Imperiled frog morphology

Closed. This professor is continuing with Spring 2021 apprentices on this project; no new apprentices needed for Fall 2021.

The Cascades Frog (Rana cascadae) is an imperiled species native to western North America. This frog ranges from northern California along the Cascade mountain range through Oregon and Washington. It also occurs in a disjunct population in the Olympic Mountain range of Washington’s Olympic Peninsula. The goal of this study is to measure Cascade Frog anatomical differences in populations from across its range using specimens at UC Berkeley’s Museum of Vertebrate Zoology and other museums like the California Academy of Sciences in San Francisco. The research apprentice will use calipers and other tools (e.g., x-rays) as needed to assess body shape and size differences among populations. This species is undergoing review for listing under the United States Endangered Species Act and results from this study will help in assessing whether Cascades Frog should become a listed species. The data from this study will be merged with an ongoing genomic analysis by the Washington Department of Fish and Wildlife to determine whether there is any important genetic and anatomical differentiation among Cascades Frog populations. Emphasis will be placed on samples that might differentiate the Olympic Mountain population from the Cascades populations. In addition to informing the possible federal listing of Cascades Frog, data from this work will also be published in the peer-reviewed scientific literature with the apprentice as a co-author.

The research apprentice will be responsible for helping identify relevant specimens at Berkeley’s Museum of Vertebrate Zoology and other museums and coordinating access to these specimens. Additionally, the apprentice will help design the study protocols and will be responsible for measuring specimens, recording detailed measurements, and taking thorough notes throughout the analysis. Time permitting, the apprentice may assist with statistical analyses and writing a report on the results. The apprentice will work with Professor Rebecca Tarvin (UC Berkeley) and Dr. Max Lambert (Washington Department of Fish and Wildlife) on this project. Students will have the opportunity to gain training in conservation biology and amphibian morphology . An overall expected outcome is to develop scientific skills and help prepare for a career in biology, policy, or conservation.

Day-to-day supervisor for this project: Dr. Max Lambert, Aquatic Research Section Manager Science Division, Habitat Program, Washington Department of Fish and Wildlife

Qualifications: Qualified applicants should have a strong attention to detail, the ability to collect clear and detailed data and notes, and have a basic understanding of organismal biology and vertebrate anatomy. Laboratory experience and experience with calipers or studying museum specimens would be valuable but not essential. Preferred qualifications also include an interest in conservation biology, natural history collections, and herpetology.

Weekly Hours: 6-8 hrs

Related website: https://lambertmr.wordpress.com
Related website: https://www.tarvinlab.org

Closed (3) A review of amphibian chemical defenses

Applications for fall 2021 are now closed for this project.

Amphibians -- frogs, salamanders, and caecilians -- exhibit a stunning variety of chemical defenses against predators and parasites, ranging from antimicrobial peptides to antipredator neurotoxins and biological glues! These defenses generally co-occur with physiological, morphological, and behavioral adaptations that sometimes exhibit convergence with distantly related taxa. However, research into amphibian chemical defense has been far from systematic, with many taxa receiving little or no investigation. Furthermore, while hundreds of unique chemical compounds have been identified in amphibian skin, only a fraction have known biological or ecological functions. The goal of this project is to comprehensively survey the known modes and bases of chemical defense across all amphibian taxa. This information will be compiled into a species-level database which, in addition to being a standalone resource, can serve as a foundation for future reviews and research projects.

Undergraduate students are being recruited to perform bibliographic research on amphibian chemical defenses. In this capacity, they will search literature databases (such as Google Scholar and the Berkeley Library Database), read through the papers found, and compile relevant information in an excel spreadsheet. With consideration of their particular interests, students will be assigned amphibian taxa to thoroughly review all published information on toxicity, poisonous chemicals, relevant adaptations, odor, etc. Students will gain valuable experience in navigating and reading scientific literature. They will also have the opportunity to join and participate in lab meetings and journal clubs. An overall expected outcome is to develop research, organization, and information synthesis skills and help prepare for a career in science or any other research-intensive field. Sufficiently motivated and talented students may be able to develop independent thesis projects and co-authorship status within the context of this research.

This position will likely be hybrid, with the bulk of the work being performed virtually and meetings being held in-person. However, we recognize the situation with COVID19 is fluid and the duties of this position can be performed fully virtually if needed.

Day-to-day supervisor for this project: Kannon Pearson, Graduate Student

Qualifications: Diligence, patience, communicativeness, and an enthusiasm for amphibians and/or chemical defense are essential qualities for this position. A background in biology, chemistry and/or herpetology, or prior experience reading scientific literature, would be helpful for URAP students, but is not required.

Weekly Hours: 6-8 hrs

Related website: https://www.tarvinlab.org/research