Population biology is a central field that integrates aspects of ecology, evolutionary biology, bioinformatics and mathematical modeling. UNL has strength in applied, basic, and theoretical population biology, addressing such diverse topics as modeling of population dynamics, population genetics, community diversity and structure, speciation, behavioral ecology, endangered species, invasive species, disease biology, and wildlife biology. The goal of our Program of Excellence is to add to that expertise, and thus increase intellectual collaborations and vibrancy across the UNL campus.
With our Population Biology Program of Excellence (PoE) Postdoctoral Fellowships, we are one of only a few universities to have post-doctoral fellowships that are not tied to a particular PI and grant. The goal of the Population Biology POE Postdoctoral Fellowship is to stimulate synergistic interactions between faculty and postdoctoral scholars interested in the broad area of Population Biology.
Appointed postdocs develop a single, coherent 2-year research project under the guidance of one, two or more faculty advisors, one of whom is in the Ecology, Evolution & Behavior (EEB) section in the School of Biological Sciences.
Applications Now Being Accepted
Population Biology Postdoctoral Research Fellowship
THE UNIVERSITY OF NEBRASKA-LINCOLN is seeking applications for a 2-year postdoctoral position in the Population Biology Program of Excellence.
The goal of the Population Biology-POE Postdoctoral Fellowship is to stimulate synergistic interactions between faculty and postdoctoral scholars interested in the broad area of Population Biology. We are seeking applications from recent PhDs who show promise of conducting cutting edge research related to, and expanding upon, faculty research areas in the Ecology, Evolution & Behavior (EEB) section in the School of Biological Sciences (https://biosci.unl.edu/research-areas). The POE also seeks to identify potential postdoctoral fellows who will enhance graduate education, serve as a model for graduate students in career development, and promote interactions among faculty at UNL. Qualified candidates are required to submit a 2-3 page research proposal detailing the two-year program of research to be completed under the guidance of a faculty member in the Ecology, Evolution & Behavior (EEB) section in the School of Biological Sciences. Applicants are encouraged to reach out to potential faculty mentors before developing a proposal for additional guidelines and suggestions. The position does not include research funds so the extent of contributions from the faculty sponsor should be addressed in the proposal. While in residence, the postdoctoral fellow will be expected to lead a seminar, symposium or outreach project that will appeal to Population Biologists across campus. Applications must include a CV, a 1-page description of previous or current research and the description of proposed research. In addition, the applicant must arrange for two recommendation letters from non-UNL faculty, and one from the UNL faculty sponsor (a total of 3 letters) to be emailed to the address below. The expected salary will be $45,000 per year with a start date of August 19, 2018. Priority will be given to applicants who have completed their degree and are new to UNL. Research descriptions for past and current POE postdoctoral fellows can be viewed at http://biosci.unl.edu/population-biology/
Application materials should be emailed to: Dr. Johannes Knops at: firstname.lastname@example.org. The subject line should read “Population Biology Post-doc application”. Applications should be received by March 1, 2018. We anticipate notifying the successful applicant by April 1, 2018, with a starting date of August 19 or later in 2018. We strongly encourage applications from women and members of minority groups. The University of Nebraska is committed to a pluralistic campus community through affirmative action, equal opportunity, work-life balance, and dual careers. We assure responsible accommodation under the Americans with Disabilities Act. See http://www.unl.edu/equity/notice-nondiscrimination.
School of Biological Sciences, University of Nebraska-Lincoln
Manter Hall 335
My research interests are focused on identifying specialized adaptations in organisms and understanding how they work and how they evolved. I consider myself a highly collaborative and integrative biologist, and I explore research questions that cut across traditional disciplinary boundaries. Consequently, I design my studies to investigate broad-scale patterns of organismal evolution as well as mechanisms of adaptation at different hierarchical levels of biological organization, from organismal physiology to molecular function. Currently, I am applying this interdisciplinary approach to researching the mechanisms of toxin resistance in predators of toxic prey.
My research as a PoE fellow is aimed at using the predator/toxic prey system to answer fundamental questions of evolution. For example, how do novel phenotypes evolve in an incremental, step-by-step fashion? Specifically, I am investigating a protein adaptation that allows certain species of snakes to feed on toxic toads. Toads synthesize potent cardiotonic steroids known as bufadienolides. These toxins exert their effect by inhibiting ion transport by the Na+/K+-ATPase. Inhibition of this ubiquitous transmembrane protein leads to a cascade of intracellular ion imbalances, which are lethal in most organisms. Molecular resistance to bufadienolides in snakes has been attributed to two amino acid substitutions in the Na+/K+-ATPase. As a PoE fellow I am working on better understand how this adaptation evolved by statistically reconstructing ancestral Na+/K+-ATPase sequences in a phylogenetically broad sample-set of snakes and experimentally “resurrecting” ancestral proteins at keys points in evolution using a protein engineering approach. I plan to utilize the “resurrected” proteins to assay bufadienolide sensitivities and functional efficiencies. With these data I can trace the trajectory of change in bufadienolide resistance in all mutational intermediates that connect the ancestral (sensitive) Na+/K+-ATPase and the descendant (resistant) Na+/K+-ATPase in the common ancestor of bufadienolide-resistant clades. This work will provide a complete genetic and physiological reconstruction of the evolution of bufadienolide resistance in snakes, and can be applied to an array of other adaptation systems.
PoE Advisor: Jay Storz
School of Biological Sciences, University of Nebraska-Lincoln
Manter Hall 424
My research combines theory from community ecology and evolutionary epidemiology to understand how feedbacks between individual-level and population-level processes shape both ecological and evolutionary dynamics. Ultimately, this research contributes to a more general understanding how global change (in e.g., resources, diet, dissolved organic carbon, UV radiation) influences host physiology and behavior and how these individual-level processes scale up to influence population dynamics, disease epidemics, and parasite evolution.
With the PoE fellowship I am working with Dr. Clay Cressler to examine how changes in resources (diet) influence physiological trade-offs between host defense and basic life history traits in ways that modulate host-parasite evolution. Host physiology governs host defense against parasites, from avoidance of infection via altered behavior or mechanical barriers to strategies that reduce or offset fitness consequences once infected. These energetically-expensive mechanisms all carry different costs and benefits for the host and parasite, and strongly influence evolution. To date, however, most research has focused on only subsets of these interactions. Hence, we lack a fundamental understanding of feedbacks between these different mechanisms. To address this gap, Dr. Cresller and I are combining experiments and theory that incorporates principles from food web ecology and evolutionary epidemiology to study interactions between environmental factors, individual-level traits, and population-level dynamics.
PoE Advisor: Clay Cressler
School of Biological Sciences, University of Nebraska-Lincoln
Manter Hall 410
My research investigates interactions between ecology and life-history evolution. My work with amphibians focusses on how life history strategies affect ecosystem processes such as energy and nutrient cycling. Small isolated wetlands can produce tons of amphibian mass (recently metamorphosed juveniles) that moves into the surrounding terrestrial environment as nutrient-rich packets of energy. Similarly, adults transfer terrestrial nutrients and biomass into wetlands during the breeding season (eggs). Life history strategies shape the nutrient content and mass of each of these biomass vectors (eggs, juveniles) and, when combined with trophic interactions, determine the direction, magnitude, and stoichiometry of nutrient and energy transfers between ecosystems.
One of my ongoing projects investigates how body size in a size-structured population of large aquatic salamanders responds to environmental perturbations. This research has given me insight into how long-lived ectotherms can demonstrate patterns of positive body size selection during severe droughts (a pattern counter to that seen in other groups of ectotherms). Longitudinal studies of vertebrates in the field are useful, but come with limitations that are not easily overcome. For example, manipulating climatic variables and studying several generations of vertebrates in multiple replicated populations is generally infeasible.
As a PoE fellow, I will be working with Drs. DeLong and Brassil to continue my line of inquiry into how organisms respond to environmental perturbations, but will utilize the fast generation times and easily manipulated environments of algae and protists. We are primarily interested in how organisms respond to increased climatic variation and changes to resource stoichiometry (C:P ratio). The effects of these factors on body size, population dynamics and thermal performance will be used to inform mechanistic models already in development by the population ecology work group at the University of Nebraska. The multi-generational approach of these experiments will reveal how climate variability and resource stoichiometry shape the evolution of thermal performance curves. These findings and resulting models will contribute to our understanding of how human-altered systems will affect organisms across ecological as well as evolutionary time scales.
My research focuses on understanding the processes guiding the evolution of animal communication systems, and how divergence in communication systems relates to speciation. During my PhD, I utilized the recently diverged barn swallow species complex as a model for understanding the role of sexual selection in shaping phenotypes within and across populations. In particular, a three year study within a Colorado population highlights that male-male competition and female choice seem to involve different acoustic and visual signals. My PhD work also characterizes broad patterns of signal variation in feather plumage and male song across 19 sample populations distributed across the Northern Hemisphere, highlighting divergence in one song element (trill rate) among subspecies. A further playback experiment in Colorado demonstrates important interactions between dynamic traits (such as trill rate) and static traits (such as breast feather color) in mediating competitive interactions. Collectively this work provides insight into the evolutionary dynamics of complex sexual signaling at multiple spatial scales.
As a UNL Program of Excellence Postdoctoral Fellow, I will work with Drs. Dai Shizuka and Eileen Hebets to apply network statistical approaches to the study of complex signaling. We will use data on barn swallows from my PhD, as well as new data from a number of Schizocosa wolf spider species in order to draw broad conclusions about the functions of intra- and intersexual selection in divergence in communication systems across diverse animal taxa. Because sexual selection studies have often focused on a small number of traits, whereas signals often comprise many elements and modalities (e.g. visual, acoustic, or olfactory), a network approach to complex signaling offers many benefits for identifying constraints, trade-offs, and the potential for redundancy affecting the evolution of communication.
Current Position: Adjunct Faculty at University of Colorado-Denver; Postdoctoral Researcher at University of Colorado-Boulder
As a UNL Program of Excellence Postdoctoral Fellow, I am investigating the ecological effects of plant-pollinator interactions to better understand potential and realized gene flow among the ploidy levels of creosote bush.
PoE Advisor: Diana Pilson
Current Position: Postdoctoral Researchers at Univeristy of Minnesota-Twin Cities
As a postdoctoral researcher in the Population Biology PoE, I am investigating a wider range of possible disturbances on freshwater ecosystems, by accounting for consequences of global change, including temperature change and altered dissolved oxygen availability. I am specifically interested how these changes, single and in combination impact the energy budgets and metabolism of key macroinvertebrate species and how the impacts at the individual level translate to consequences for populations and ecosystem functioning. To this end, I use a combination of laboratory experiments and population modelling, specifically IBMs.
PoE Advisor: Valerie Forbes
Current Position: Assistant Professor, University of Missouri-St. Louis
After the fellowship, I accepted a position as an Assistant Professor at the University of Missouri - St. Louis. My time at UNL led to one publication to date, with various other projects in the works.
PoE Advisor: Stacey Smith
Current Position: Postdoctoral Fellow at the Mathematical Biosciences InstituteI am broadly interested in how local-scale processes affecting individual plants influence patterns at the population, community, and ecosystem levels. Using a combination of experiments, observations, and statistical models, I quantify the relationship between plant attributes and plant interactions with their environment to enable prediction for unstudied species, gain insight into mechanisms for species coexistence, and examine ecosystem function under global change. Because empirical approaches are limited in temporal, spatial, and organizational scales, I use mathematical models to explore macroscopic patterns resulting from processes occurring over multiple scales.
The PoE at UNL gave me several teaching opportunities. In Fall 2011, I designed a writing-intensive undergraduate- and graduate-level seminar on secondary compounds in plant communities. In Spring 2012, I was a guest instructor in Dr. Russo's Ecological Interactions course in which I taught a weeklong section on the influence of herbivory on plant communities, with a focus on population regulation, species coexistence, and evolution of plant defenses. In Fall 2010, I taught a class on plant populations dynamics in Dr. Russo’s course, Introductory Botany.
UNL has many opportunities for postdocs to further their professional career. I attended workshops offered by organizations such as ADVANCE-Nebraska and the Postdoctoral Advisory Council, including ‘Making a Successful Transition to an Academic Career’ led by Dr. Kamau Siwatu, ‘Teamwork and Leadership Skills for Postdocs’ led by Dr. Sharon Milgram, and ‘Interrupting Bias in the Faculty Search Process’ led by Dr. Joyce Yen. In addition, UNL gave me the opportunity to attend 'Transitioning to Faculty Life: A Conference for Postdocs Underrepresented in STEM' organized by the Committee on Institutional Cooperation and held at The Ohio State University.
I also had many opportunities for academic service, educational outreach, presenting my own work and broadening my professional network.
PoE Advisor: Sabrina Russo
Current Position: Postdoctoral Associate, UNL SBS and Entomology Department
A major focus of my research is to understand effects of environmental variation on population and evolutionary dynamics. I try to integrate mathematical models and data to make predictions about demographic (e.g., population abundance) and genetic (e.g., allele frequency) changes. I also work in applied ecology, especially in developing models to study resistance evolution in agricultural pests to pesticides and transgenic plants.
I have enjoyed being a PoE postdoc for the freedom it provided for independent work. During my PoE (2010-12) I also started collaboration with students and faculty in the entomology department which helped in acquiring funds for my future work.
Publications resulting from PoE collaborations
C. V. Haridas., H. R. Prendeville, D. Pilson and B. Tenhumberg. Response of Population Size to Changing Vital Rates in Random Environments. (2013). Theoretical Ecology, 6: 21 - 29.
E. A. Eager, C. V. Haridas, D. Pilson, R. Rebarber, and B. Tenhumberg. Disturbance frequency and vertical distribution of seeds affect long-term population dynamics: a mechanistic seed bank model. (2013). The American Naturalist, 182: 180 - 190
B.D. Siegfried, M.Rangasamy, H.Wang, T.Spencer, C.V.Haridas, B. Tenhumberg, D. V. Sumerford, and N. P. Storer. Estimating the frequency of Cry1f resistance in field populations of the European Corn Borer (Lepidoptera: Crambidae). (2013). Pest Management Science. DOI: 10.1002/ps.3662
A. M. Velez, T. Spencer, A. Alves, D. Moellenbeck, R. Meagher, H. Chirakkal, B.D. Siegfried. Inheritance of Cry1F resistance, cross-resistance and frequency of resistant alleles in Spodoptera frugiperda (Lepidoptera: Noctuidae). (2013). Bulletin of Entomological Research. DOI:10.1017/S0007485313000448C.V. Haridas, Kathleen H. Keeler, and B. Tenhumberg. Variation in the local population dynamics of the short-lived Opuntia macrorhiza (Cactaceae). (In revision)
PoE Advisor: Brigitte Tenhumberg
Laura Sullivan Beckers
Current Position: Lecturer, Indiana University
During my time as a POE fellow, I investigated how the experiences that a male spider has while trying to woo a female effect his subsequent courtship behavior. This research question was developed as an independent (i.e. not tied to an external grant) project with my advisor, Eileen Hebets. She and I both had an interest in how social experiences shape mating behavior, but she was not working on those questions when I joined the lab. Having the support of the POE allowed us to delve into that line of research.
For two years we conducted experiments aimed at uncovering whether males do change behavior with experience, and whether such a change would have a selective advantage. The results of the first experiment have been published in Animal Behaviour, and the results of the second experiment (conducted in the second year of the POE fellowship) are currently in press at the same journal. Our findings have led to many more questions that I hope to answer in the future.
PoE Advisor: Eileen Hebets
Current Position: Assistant Professor in Zoology at Saginaw Valley State UniversityMy research while at UNL included many questions from systematics to population genetics. I was constructing a data matrix of multiple nDNA loci for 2 general of Neotropical fishes and then assisting with the Euteleostei Tree of Life. There were many visiting students in the Orti lab from South America [Argentina, Brazil], one of whom was also working on the same fish group and developing microsatellites for population-level questions. I developed a local project in cooperation with NGPC on two species of cyprinids living in the Missouri River basin. We then enlisted assistance from various state and federal agencies from MT, ND, and MO for fish collection. This project was addressing population-level differences above and below the 5 major dams on the Missouri River. I would also volunteer with NGPC on the Missouri River. Finally, I tried to spend a day/week at the museum on campus assisting the curator of the zoology division by tending to the collection, and sorting specimens.
While at UNL I taught a seminar in "Aquatic Ecology" at School of Natural Resources (SNR), and then a course in "Molecular Ecology" with 2 other postdocs in the SBS, and co-taught "Ichthyology" with a professor from SNR. I enjoyed the teaching, and I think that was more than the programme required of me.
I was at UNL for 2 years, since then was in Chicago for 3 yrs, and now I am in MI, where I have a position as Assistant Professor teaching zoology for bio-majors, biology for non-majors, and a senior seminar.
PoE Advisor: Guillermo Orti
Dr. Henaux worked on two projects while at UNL (avian cholera/snow goose ecology and mountain lion migration); additional funding for her work was provided by the US Fish and Wildlife Service. The mountain lion work provided connections for Dr. Powell in Africa (where he was recently on a Fulbright Fellowship). Dr. Henaux taught a graduate course in stable isotope methods.
PoE Advisor: Drew Tyre and Larkin Powell
Current Position: Assistant, Mississippi State University
The PoE fellowship I held between 2005 and 2007 was instrumental in my career. Briefly, I worked on the evolution of the hemoglobin gene family in mammals. The PoE allowed me to enter the fields of bioinformatics and comparative genomics, provided valuable interactions with several faculty members at the School of Biological Sciences at UNL, and sharply improve my publication record (10 of my publications are a direct result of the work I did with the PoE).
My current research is a direct extension of the research I did while funded by the PoE, and I still work with some of the people I met during my PoE tenure, including my formed postdoctoral advisor, Jay Storz. I think it is safe to say that the PoE was key in my success. In addition to academic success, as a family we enjoyed our time at UNL very much, we made many friends at UNL, and found a supportive community.
PoE Advisor: Jay Storz