Faculty & Staff

General contact

Phone: 507.222.4884
Fax: 507.222.5757


Jennifer Ross Wolff
Jennifer Wolff Profile
Associate Professor of Biology
Chair of Biology

   Dr. Wolff is a developmental biologist interested in the embryonic development of the nervous system. She is currently using genetic and molecular approaches to investigate how male-specific neurons that control mating arise during development in the model organism C. elegans. She teaches Animal Developmental Biology, Developmental Neurobiology, part of Introductory Biology, and Biotechnology, Health, and Society.  Dr. Wolff is Chair of the Department.

Rika Anderson
Rika Anderson ’06 Profile
Assistant Professor of Biology
Off Campus: Fall 2019 through Spring 2020

Rika Anderson ’06 is an environmental microbiologist interested in how microbes and their viruses evolve, adapt, and diversify. She is currently using bioinformatics approaches to investigate how marine microorganisms evolve in response to the extreme environment of deep-sea hydrothermal vents. She is particularly interested in understanding what this can teach us about the origin and early evolution of life on our planet. She teaches Genomics and Bioinformatics and part of Introductory Biology.

Annie Bosacker, Biology
Annie Bosacker ’95 Profile
Lecturer in Biology

Annie Bosacker ‘95, lecturer (Carleton College, BA; University of Minnesota, MS, PhD) is a zoologist who teaches behavioral ecology and introductory biology labs. She also directs the department’s ecology program in Australia, and she is interested in how to promote learning and scientific reasoning skills in a field course.

Dr. Charles Crutchfield
Charles Crutchfield ’82 Profile
Benedict Distinguished Visiting Professor of Biology

Email: Charles@CrutchfieldDermatology.com

   Dr. Crutchfield '82 is a board certified dermatologist with a clinical practice in Eagan, Minnesota. In addition to his M.D. degree, Dr. Crutchfield also has a Master’s degree in Molecular Biology from the Mayo Clinic. He has co-authored the dermatology textbook ‘A Clinical Atlas of 101 Common Skin Diseases’ and authored over 100 scientific articles and publications. His research interests include psoriasis and ethnic skin disorders. Dr. Crutchfield teaches the spring upper level biology seminar “Cutaneous Biology for the Pre-Medical Student”.  Carleton BA; Mayo, MA, MD.

Sarah Deel
Sarah Deel Profile
Senior Lecturer in Biology

   Sarah Deel is trained as an invertebrate biologist with a focus on endosymbiotic relationships in marine invertebrates. She is interested in how students best learn new concepts and skills in biology, and in how students utilize research experiences to deepen their understanding of biology. At Carleton, she has been involved with laboratory sections of Intro Biology, Animal Physiology, and Genetics. Currently she is developing, preparing, and teaching labs for Intro Biology I: Energetics and Genetics (Biol 125).

Andrew Grenfell
Andrew Grenfell Profile
Visiting Assistant Professor of Biology

Dr. Grenfell is a biochemist and microbiologist interested in understanding how bacteria of the intestinal microbiota colonize and persist within host animals. He studies Shewanella species isolated from the zebrafish (Danio rerio) intestinal tract to better understand how secreted molecules from bacteria and unusual CRISPR-Cas systems allow some species to flourish in the gut. He is teaching Biochemistry this winter and Animal Development in the spring.

Daniel Hernandez
Daniel Hernandez Profile
Associate Professor of Biology
Off Campus: Fall 2019 through Winter 2020

   Dr. Hernandez is an ecosystem ecologist researching the effects of changes in plant communities (from disturbance, herbivory, and loss of biodiversity) on carbon and nutrient cycling in savannas and grasslands. Current research includes investigating the consequences of nitrogen deposition and cattle grazing on serpentine grasslands in California and the role of mammalian herbivores in the structure and function of restored prairies in the Arb. He teaches courses on Ecosystems Ecology, Global Change Biology, Grassland Ecology, and Introductory Biology.

David Hougen-Eitzman
David Hougen-Eitzman Profile
Senior Lecturer in Biology

   Dr. Hougen-Eitzman, a senior lecturer (St. Olaf College, BA; Duke University, PhD), teaches entomology and introductory biology, as well as an agroecology class that visits China.  He is Farm Club’s adviser and is conducting research on sustainable agriculture.

Fernan Jaramillo
Fernan Jaramillo Profile
Professor of Biology

Dr. Jaramillo is a neurobiologist interested in sensory systems, the neuromuscular synapse, and the neurobiology of zebrafish. He teaches Neurobiology, Human Physiology, and a Neuroscience seminar.

Mark McKone
Mark McKone Profile
Research Supervisor of Cowling Arboretum
Towsley Professor of Biology
Off Campus: Winter 2020 through Spring 2020

   Dr. McKone is an evolutionary ecologist, pursues research on the interactions between insects and plants. Particular interests include the pollinator community of prairie composites and the evolutionary impact of pre-dispersal seed predators of grasses. He teaches Evolution, Population Ecology, Evolution of Sex and Sexes, and part of Introductory Biology.

Raka Mitra
Raka Mitra Profile
Associate Professor of Biology

Dr. Mitra is a molecular and cellular biologist interested in the interactions between plants and microbes. Her lab studies bacterial pathogens of plant roots with the goal of understanding disease development and plant defense. Current lab projects involve elucidating the role of bacterial effector proteins in pathogenesis of the model plant Arabidopsis thaliana. Dr. Mitra teaches courses in Microbial Pathology, Cell Biology, and part of Introductory Biology. 

Mike Nishizaki
Mike Nishizaki Profile
Assistant Professor of Biology

Dr. Nishizaki is an aquatic biologist interested in the interaction between organisms and their physical environment.  Current research projects use marine/freshwater invertebrates to examine biological responses (e.g., behavior, respiration, gene expression) to fluctuating environmental conditions. Projects typically involve some combination of field work, lab work, computer modeling, and aquarium/animal care.

Matt Rand
Matt Rand Profile
Professor of Biology

Dr. Rand, a vertebrate reproductive biologist, studies the hormonal mediation and function of sexually dimorphic traits. Currently he is looking at the role of genes in determining pigment differences in Sceloporus lizards. He teaches Animal Physiology, Vertebrate Morphology, a seminar on Behavioral Genetics, part of Introductory Biology, and a non-majors course that explores the biological basis of reproduction and sexuality in Humans.


Rou-Jia Sung
Rou-Jia Sung Profile
Assistant Professor of Biology
Debby Walser-Kuntz
Debby Walser-Kuntz Profile
Professor of Biology

Dr. Walser-Kuntz is an immunologist, is interested in the role the immune system plays in the development of autoimmune disorders and the potential impact on this process of environmental contaminants. We are testing how a common plastic component, bisphenol A, affects immune cell activation and cytokine responses. She teaches Immunology, Microbiology, part of Introductory Biology, a seminar on Topics in Virology and Methods of Teaching Science. 

Stephan Zweifel
Stephan Zweifel Profile
Head Coach, Men's Tennis
Professor of Biology
Off Campus: Fall 2019

Dr. Zweifel is a geneticist and molecular biologist, is examining the replication and segregation of mitochondrial DNA in the yeast S. cerevisiae. His lab is interested in identifying and characterizing the nuclear genes responsible for the proper transmission of the mitochondrial genome. He teaches Genetics, Molecular Biology, part of Introductory Biology, and a seminar on Behavioral Genetics.

Emeriti Faculty

Gerry Hill
Gerry Hill Profile
Towsley Professor of Biology, Emeritus
Susan Singer
Susan Singer Profile
Laurence McKinley Gould Professor of the Natural Sciences, Emerita
John Tymoczko
John Tymoczko Profile
Towsley Professor of Biology, Emeritus

  Dr. Tymoczko is a retired biochemist, who taught biochemistry and related courses at Carleton for 40 years. He is a co-author of five editions of Stryer's Biochemistry, with the recent publication of the 9th edition. He is also co-author of four editions of an introductory level biochemistry text, Biochemistry, A Short Course. The 4th edition of this text has just been published.

Gary Wagenbach
Gary Wagenbach Profile
Winifred and Atherton Bean Professor of Biology, Science, Technology, and Society, Emeritus

Dr. Wagenbach, an invertebrate zoologist worked on the population biology of threatened freshwater mussels in regional rivers. He taught a variety of courses during his 39 years at Carleton including at off-campus locations, environmental studies courses, and served a stint as Director of Environmental and Technology Studies.  At present he is helping with teacher professional development in a new K-12 school in Yangon, Myanmar (Burma).  Please contact Dr. Wagenbach at gwagenba@gmail.com.


Lorie Tuma
Lorie Tuma Profile
Administrative Assistant in Biology
Assistant to Pre-Health Advisor

B.A. (cum laude), Concordia University, Organizational Management and Communications. She manages all aspects of department events, recruitment searches and guest speaker visits (budgets, scheduling, publicity, transportation, accommodations, catering). Provides organizational and administrative assistance for Chair and faculty. Maintains faculty hiring procedures. Oversight of department budget, catalog, and course schedule, along with faculty VISA statement reviews. Track majors’ Biology course requirements and comps completion. Builds and maintains Biology Department Website and department Facebook page. Works directly with Student Departmental Advisers (SDAs), Department Curriculum Committee (DCCs), and serves as the Student Work Supervisor for the Biology Office. Fields department and campus questions for students, staff, faculty, alumni, and visitors.


Nancy Braker
Nancy Braker ’81 Profile
Lecturer in Biology
Puzak Family Director of the Cowling Arboretum
Office: Arb 122

Nancy Braker (BA Carleton; MS University of Minnesota - Entomology) is a conservation biologist.  She has 20 years of experience working for The Nature Conservancy in land management, conservation planning, and monitoring of rare species populations, specializing in management of fire adapted natural communities.  Nancy oversees all aspects of management of the Cowling Arboretum and McKnight Prairie, and works with faculty, students and outside users on research and use of the properties.

Shawn Galdeen
Shawn Galdeen Profile
Biology Laboratory Manager

Shawn is a cell biologist who has an unhealthy fascination with microscopy.  His interests have led him to previous work on cellular adhesion, phototoxicity in fluorescence microscopy, and a survey book chapter on microscopy techniques.  As the former chair of a national postdoctoral subcommittee, he also enjoys talking about career options both inside and out of the scientific community.  He is responsible for maintenance of all of the department's scientific equipment, as well as coordinating reagent preparation and distribution to the faculty -- with lots of student help!

Randall Hagen
Animal Colony Supervisor
Greenhouse Supervisor

Randy has a BA in Geology from Gustavus Adolphus College and both an MA in Anthropology and MS in Plant Sciences from the University of Arizona. Prior to joining the Biology department at Carleton in 2009, he had over 20 years of research and commercial experience in plant propagation,hydroponic growing and greenhouse production.  Randy serves as supervisor of the biology greenhouse, zebrafish lab, and animal colony facility. Current research interests include testing new lighting systems, propagation of rare plants,and development of improved hydroponic/aeroponic systems growing systems.