Biology Seminars Spring 2022

Biology Seminars for Spring 2022

January

Friday January 21 - No Seminar
 
Friday January 28, 3:00 p.m., via Zoom

Title: Plant-insect interactions and their implications for population and species connectivity, diversity, and conservation
Dr. Krissa Skogen
Associate Conservation Scientist, Chicago Botanical Garden
Hosted by: Dr. Amanda Grusz
To join the seminar click this link: https://umn.zoom.us/j/92760837234
Paper 1: Wenzell et al. 2021
Paper 2: Skogen et al. 2019
Paper 3: Jogesh et al. 2016

February

Friday February 04 at 3:00 p.m. via Zoom

Joint Seminar with Dept. of Biology and Dept. of Chemistry and Biochemistry
Sponsored by the Institute for Advanced Studies and the Institute on the Environment, University of Minnesota
Title: Medicine Lines and Polycultures: Re-animating Science through Biocultural Restoration
Dr. Melissa Nelson
Professor, Arizona State University
Hosted by: Dr. Jennifer Liang (Biology Dept. contact)
To join the seminar: https://umn.zoom.us/webinar/register/WN_ddjC2m0NSyeMBQQRE4LqiA
Paper 1: Nelson 2021
Paper 2: Nelson and Harjo 2020
Paper 3: Nelson 2018

Friday February 11, 2022 at 3:00 p.m. via Zoom

Darwin Day Seminar with Dept. of Biology and Dept. Earth & Environmental Sciences
Title: The rise and fall of ancient lakes in western North America
Dr. Daniel Ibarra
Professor, Brown University
Hosted by: Geology Dept. in 2022
Abstract: TBD
Paper 1: Ibarra et al. 2018
Paper 2: D’Antonio et al. 2019

Friday February 18, 2022 at 3:00 p.m. in Life Sciences 185 and via Zoom

Title: Mycorrhizal dynamics at the temperate-boreal ecotone: effects of climate change host performance and fungal community composition
Dr. Peter Kennedy
Professor, University of Minnesota
Hosted by: Dr. Julie Etterson
To join the seminar: https://umn.zoom.us/j/95500531951?pwd=Rm84dFpIalhTMW16aG9nQmE5WGhWQT09

Abstract: Mycorrhizal symbioses are increasingly recognized as important mediators of plant community dynamics and ecosystem responses to global change. With the improved ability to identify fungal communities in soil, there is also rising interest in understanding how mycorrhizal fungal communities themselves respond to altered environmental conditions. In this seminar, I will discuss research from our lab that has been conducted at the B4Warmed Experiment at the temperate-boreal forest ecotone in northern Minnesota. Our research at B4Warmed  has focused on three areas: 1) exploring links between aboveground plant performance and changes in the composition of associated mycorrhizal fungal communities, and 2) determining how the structure of mycorrhizal fungal networks among trees are affected by increased temperature and reduced rainfall and 3) assessing the repeatability of changes in mycorrhizal fungal community structure experimental across multiple plant cohorts.
Paper 1: Fernandez et al. 2017
Paper 2: Cahanovitc et al. 2022

Friday February 25, 2022 at 3:00 p.m. in Life Sciences 185

Title: Research on genetics of chromatin regulation in the war against cancer
Dr. Alexei Tulin
Professor, University of North Dakota
Hosted by: Dr. Huai Deng
Abstract: Our long-term goal is to explore poly(ADP-ribosyl)ating pathways to understand how cells can undergo rapid, local and reversible chromatin reprogramming, thus fine-tuning the induction of local gene activity.  Our key discovery has been that PARP1 controls chromatin decondensation at large number of loci including hormone-dependent developmental, heat shock responsive, and immunity genes.  Eventually, we will be able to reprogram genes located within repressed chromatin by artificially activating nearby chromosomal Poly(ADP-ribose)Polymerase 1 (PARP-1) proteins.  Understanding how PARP-1 acts within normal, undamaged chromatin will advance our knowledge of developmental gene regulation and facilitate the development of new anti-cancer drugs for clinical applications and of methods to experimentally re-program gene expression.
Paper 1: Thomas et al. 2016
Paper 2: Thomas et al. 2014

March

Friday March 04 - Last Day of Class Before Spring Break - No Seminar
 
Friday March 11 - Spring Break - No Seminar
 
Friday March 18, 2022 at 3:00 p.m. in Life Sciences 185

Title: Climatological suitability and water use characteristics of Quercus populations
Erin Bergen
IBS M.S. Thesis defense
Hosted by: Dr. Julie Etterson and Dr. Salli Dymond | Zoom link: https://tinyurl.com/UMDBiologySeminar
Abstract: Climate change has led to northward shifts in temperature profiles and disruptions to precipitation regimes. The northern regions of Minnesota are warmer than they once were, and rainfall is falling into a pattern of drought and deluge. Since these changes are expected to continue over time, it is important to consider the adaptation capabilities of long-lived, immobile species such as trees. The speed of climate change has surpassed the migratory ability of tree populations. Climate shifts engender mismatches between the local adaptations of forested ecosystems and current environmental conditions. A possible solution to these "adaptation lags" is assisted migration. To determine the best candidates for vegetative restoration efforts, my work compares the phenological and water use traits of local, northern and nonlocal, southern populations of oak species in northern Minnesota. On the basis of biological timing, southern trees have demonstrated more compatibility with current climate conditions than northern trees. The populations are distinctly different in terms of budburst, canopy acquisition, senescence, and duration of canopy retention. I also measured the water use of these trees. In forested ecosystems, trees may be responsible for conducting more that 60% of the water present in the watershed into the atmosphere. Water use of different tree stock, therefore, is an important consideration. Given disparities in growth habits and related traits, southern and northern populations do differ significantly in their potential hydrologic impact. This project demonstrates that climatological suitability and hydrologic impact can be significant at a population as well as species scale, which has implications for restoration efforts and forest ecology in Minnesota and beyond.
Paper 1: Bauweraerts et al. 2013
Paper 2: Juice et al. 2016
Paper 3: Hamel et al. 2015

Friday March 25, 2022 at 3:00 p.m. in Life Sciences 185

Title: Fragments of spread: Interactions between landscape structure and animal behavior shape wildlife populations
Speaker: Dr. James Forester, Associate Professor, University of Minnesota Twin Cities
Hosted by: Dr. Ron Moen | Zoom link: https://tinyurl.com/UMDBiologySeminar
Paper 1: Oliveira-Santos et al. 2021

April

Friday April 01, 2022 at 3:00 p.m. in Life Sciences 185

Title: How does plant growth, source leaves, and sink roots impact vascular structure
Elise Miller
IBS M.S. Thesis defense
Hosted by: Dr. Jessica Savage |Zoom link: https://tinyurl.com/UMDBiologySeminar
Abstract: TBD
Paper 1: Savage et al. 2017
Paper 2: Zhang et al. 2015

Friday April 8, 2022 at 3:00 p.m. in Life Sciences 185

Title: Mammals, truffles, and trees: linking above- and below-ground interactions
Dr. Ryan Stephens
Post-Doctoral Associate, University of New Hampshire
Hosted by: Dr. Ron Moen and Dr. Michael Joyce | Zoom link: https://tinyurl.com/UMDBiologySeminar
Abstract: Ryan is a community ecologist interested in how habitat associations, resource availability, and biotic interactions influence the dietary niche of mammals and their role as dispersers of mycorrhizal fungal spores in forests. Mycorrhizal fungi are symbionts that colonize tree roots and are essential for nutrient and water uptake. Similar to pollinators, small mammals consume and disperse the fruiting bodies (mushrooms and truffles) of mycorrhizal fungi, subsequently mediating local fungal diversity and influencing establishment and growth of trees. By studying the interactions among mammals, fungi, and trees, Ryan’s research links above- and below-ground trophic interactions to better understand how forests function and to inform best wildlife management practices. Ryan integrates field surveys and experiments, both in the field and greenhouse, with isotopic analyses, microscopy, and advanced statistical modeling to understand: (1) the factors that structure the dietary niches of species over space and time; (2) how population, community, and trophic dynamics influence the functional role of species in ecosystems; and (3) how trophic interactions influence forest regeneration.
Paper 1: Stephens et al. 2020
Paper 2: Stephens et al. 2020

Friday April 15, 2022 at 3:00 p.m. in Life Sciences 185

Inspirational Teacher in the Life Sciences Awardee, Dr. Donn Branstrator
Title: Ice-covered lakes as a platform for teaching and research
Hosted by: Dr. Julie Etterson | Zoom link: https://tinyurl.com/UMDBiologySeminar
 

Friday April 22, 2022 at 3:00 p.m. in Life Sciences 185

Title: Bioluminescence and ultra-black coloration in deep-sea fish
Dr. Sonke Johnson
Professor, Duke University
Hosted by: Dr. Amanda Grusz | Zoom link: https://tinyurl.com/UMDBiologySeminar
Abstract: Although color is increasingly studied in both animals and plants, black coloration is often overlooked, even though it serves important functions. In the case of deep-sea fishes, black surfaces strongly absorb (and thus do not reflect) the bioluminescent searchlights of predators, therefore providing a form of camouflage. So, it is perhaps not surprising that many deep-sea fishes appear to be exceptionally black. We investigated this in several species of deep-sea fishes in three ways: (1) reflectance spectroscopy (2) scanning and transmission electron microscopy, and (3) optical modeling. The spectroscopy showed that many species reflected very little light, in some cases less than 0.05%, which is one hundredth of that seen in many black surfaces found in normal human experience. Interestingly, even though the reflectances were already quite low, they were generally lower in the blue-green portion of the spectrum that comprises bioluminescence, suggesting further optimization. The microscopy studies showed that the outer layers of skin of the black fishes were complex, and the ellipsoidal pigment granules found here were approximately 0.4 to 0.6 microns in diameter. Using methods developed for understanding the reflective properties of lunar soil, which is similarly composed of close-packed strongly absorbing spheroidal particles with high refractive index, we found that the melanin granules found in the black fishes were the optimal size and shape for achieving the greatest absorption of incident light with the least amount of material. Together, this study highlights the importance of low reflectance to deep-sea fishes and the strong evolutionary pressures for visual camouflage in even this dark environment.
Paper 1: Davis et al. 2020
Paper 2: Johnsen 2014

Friday April 29, 2022 - Last day of classes - No Seminar