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Biology Postdoc Minisymposium

C. Switzer, M. Taylor-Teeples, F. van Breugel, N. Gownaris
University of Washington, Department of Biology
Seminar date:
Monday, October 9, 2017 - 11:45
HCK 132
Name: Dr. Callin Switzer
Title: Pollen out all the stops: How bumble bees modify sonication behavior in response to pollen rewards
Abstract: Bumblebees often collect pollen using sonication, a behavior in which bees grasp flowers and use vibrations to release pollen. Past work suggests that flowers may be tuned to release pollen when vibrated at specific frequencies, but few researchers have investigated how bees respond to pollen rewards and learn to modify their sonication behavior. In this study, we analyzed data from over 30,000 sonication buzzes to help answer the following questions: 1.) Do the properties of the flower affect sonication frequency and/or amplitudes? 2.) Do bees change their sonication frequency to match the frequency at which the flower releases pollen? 3.) How do bees change their sonication properties when they stop receiving pollen rewards? Our approach enabled us to quickly and reproducibly conduct experiments to understand the extent to which and the reasons why bumble bees modify their sonication behavior. 
Lab Information: Postdoc, co-mentored by Tom Daniel (Biology) and Jake VanderPlas (eScience Institute)
Introduction: Callin Switzer received a PhD in Biology and a master's degree in Statistics from Harvard University. He worked with Prof. Stacey Combes and Prof. Robin Hopkins at Harvard, studying insect behavior.  He joined the University of Washington in September 2017 as a postdoc with Prof. Tom Daniel (Biology) and Dr. Jake VanderPlas (eScience Institute). 


Name: Dr. Mallorie Taylor-Teeples
TitleGoing with the Flow: Unlocking the Role of Auxin Canalization in Organogenesis
Abstract: Evolution has given rise to a staggering diversity of body plans. The growth hormone auxin plays a central role in directing plant organogenesis. Key to auxin’s role in development is a positive feedback between auxin flux and polarization of active auxin transport. This feedback system, called canalization, is hypothesized to help set up and stabilize spatiotemporal patterns of gene expression, cell division, and growth. Several theoretical models of the role that canalization plays in controlling plant architecture exist. To probe them experimentally, we used a set of synthetic promoters driving an auxin transport proteins to engineer plants with increased canalization. Effective methods for altering plant architecture are of agronomic interest, as patterning of organs around the shoot (phyllotaxy) affects light harvesting capacity and determines the density of grain or fruit along a stem.
Lab: Nemhauser lab
Introduction: Mallorie obtained her PhD in Siobhan Brady’s lab at University of California, Davis studying the transcriptional network surrounding Arabidopsis root xylem development. She joined the Nemhauser lab in 2015 to explore how the auxin signaling pathway controls plant shape and development. 


Name: Dr. Floris van Breugel
Title: Super-hydrophobic diving flies of Mono Lake
Abstract: Nearly 150 years ago, Mark Twain wrote about the remarkable alkali flies of Mono Lake. "You can hold them under water as long as you please--they do not mind it--they are only proud of it. When you let them go, they pop up to the surface as dry as a patent office report" (Roughing It, 1872). Through a combination of high speed video, scanning electron microscopy, micro-scale force measurements, physical chemistry, and comparative studies, we determined that they are able to perform this remarkable feat because of their extraordinarily hairy bodies. Other less hairy flies are less able to remain dry in Mono Lake water thanks to the high concentration of sodium carbonate, a salt that uniquely facilitates wetting of super-hydrophobic surfaces.
Lab: Riffell Lab
Introduction: Floris van Breugel received his PhD degree (2014) from Caltech, where he worked with Prof. Michael Dickinson on olfactory and visually guided search behavior of flies and mosquitoes, as well as the obscure biomechanics of alkali flies. He is currently working as a postdoc with Jeff Riffell and Nathan Kutz on the search strategies of foraging insects. 


Name: Dr. Natasha Gownaris
Title: Feet First: Adaptive Growth in Magellanic Penguin Chicks
Abstract: Natural selection theory often focuses on reproductive trade-offs, but to reach reproductive age organisms must first survive the selective pressures of juvenile stages. The adaptive growth hypothesis states that organisms should allocate resources in response to these pressures. We use a long-term dataset on skeletal and mass measurements of Magellanic penguin chicks from Punta Tombo, Argentina to test the adaptive growth hypothesis. Chick mortality averages about 65% at Punta Tombo, and most commonly results from starvation, predation, or exposure. Shape is most variable in young chicks; after 10 days of age, size consistently explains over 70% of variability between individuals. Ontogenetic and age-specific static allometry suggests that chicks prioritize growth of locomotory features, particularly feet, regardless of food conditions (i.e. lean priority model). Prioritization of feet begins during pre-hatching development. Developing a mechanistic understanding of chick growth provides insight into how conditions throughout early life stages influence adult form and function.
Lab: Boersma Lab (Center for Ecosystem Sentinels)
Introduction:Tasha received her PhD in marine science from Stony Brook University, where she studied the influence of water level fluctuations on ecosystem function and fisheries in African lakes. Since joining the Boersma lab in 2016, Tasha has been working on projects related to intraspecific variation in Magellanic penguin growth and demography. 
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