Upcoming Events

Mike Son: "The Rise in a New Era of Cholera"

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September 17, 2015 4:00 PM  – 5:00 PM
Druckenmiller Hall, Room 020

Mike Son will examine the pathogenesis of Vibrio cholerae, the Gram negative bacterium that is the etiological agent for the intestinal disease cholera. The hallmark characteristic of cholera is severe watery diarrhea and vomiting, resulting in severe dehydration of the infected individual. The disease, if not diagnosed and treated quickly and properly, will quickly lead to death of the patient within a few days. Son will discuss the primary research goal of identifying the mechanism by which newly emerging variant strains of V. cholerae are demonstrating increased virulence, causing more severe cases of the disease at a much faster rate than previously observed. A plethora of techniques used in molecular biology, bacteriology and microbiology, including genetic manipulation (DNA/RNA), gene expression assays and functional characterization of proteins are employed in research efforts.

Son is assistant professor of microbiology at Plymouth State University in Plymouth, New Hampshire. He received his B.S. in microbiology and M.S. in biochemistry from the University of Calgary. He then attended the University of Hawaii and investigated Pseudomonas aeruginosa pathogenesis during lung infections in cystic fibrosis patients. He incorporates his research and curiosity for science with his teaching to educate his students with the most up-to-date information while taking lessons from the past discoveries.

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"The role of sexual selection in speciation"

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September 24, 2015 4:00 PM  – 5:00 PM
Druckenmiller Hall, Room 020

Rebecca Safran, Associate Professor, University of Colorado, Boulder

The role of sexual selection in shaping phenotypic variation within and among closely related populations is a central theme in my research program. As an evolutionary ecologist, I am interested in the biological causes and consequences of variation in phenotype using molecular, comparative, and experimental methods. By adopting new comparative approaches (both empirical and synthetic), my current work is focused on determining how trait function affects patterns of gene flow. We are currently establishing new methods to test hypotheses about the relative contributions of geographic distance, history, natural and sexual selection in the evolution of reproductive isolation.

My research group takes advantage of the barn swallow Hirundo rustica species complex, a highly tractable, widespread and diverse study system. By conducting experiments and long-term studies both locally and across the breeding range of this young and monophyletic species complex, we aim to gain a comprehensive understanding of the evolution and maintenance of phenotypic variation from proximate (mechanistic) and functional (evolutionary) perspectives and how these affect patterns of gene flow and the evolution of reproductive isolation.

In all of our research endeavors, my research group integrates behavioral, physiological and genetic perspectives. As such, my lab is set up to conduct a variety of molecular, physiological, and endocrinological assays, and we also possess various tools for objectively measuring phenotypic variation. Presently, we conduct all of our empirical research on wild populations in the field, where experimental and comparative work are complemented by several molecular investigations in the lab.
















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Ned Friedman: "Darwin's 'Abominable Mystery' and the Search for the First Flowering Plants"

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October 8, 2015 4:00 PM  – 5:00 PM
Druckenmiller Hall, Room 020

In this presentation, Ned Friedman will discuss his current research program, which focuses on the organismic interfaces between developmental, phylogenetic and evolutionary biology. Remarkable recent advances in the study of the phylogenetic relationships of organisms have provided the raw materials for critical studies of character evolution in plants, animals, fungi, and all other forms of life. Armed with hypotheses of relationships among organisms, his work seeks to explore how patterns of morphology, anatomy and cell biology have evolved through the modification of developmental processes. 

With each study, Friedman's goal is to examine the origin and subsequent radiation of a major group of photosynthetic organisms and reconstruct the evolutionary events that led to the establishment of defining structural and developmental features of the lineage. Along with the origins of vascular plants and seed plants, the origin of flowering plants represents one of the three most significant evolutionary radiations of land plants during the last 475 million years. With over 250,000 extant species, angiosperms are the largest and most diverse group of plants ever to have evolved. 
Paradoxically, we know less about the early evolutionary history of angiosperms than we do about many considerably older groups of land plants. Indeed, Darwin's "abominable mystery" continues to challenge evolutionary biologists.

Friedman is the Arnold Professor of Organismic and Evolutionary Biology and Director of the Arnold Arboretum of Harvard University.

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Biology Seminar

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October 15, 2015 4:00 PM  – 5:00 PM
Druckenmiller Hall, Room 020

Kevin J. Peterson, Department of Biological Sciences, Dartmouth College

The explosive rise of animals 530 million years ago is among the few major events in the history of life combining the evolution of novel developmental regulatory circuitry in the context of unique environmental circumstances. This "Cambrian explosion" is the primary focus of my laboratory, and the cause(s) of the origin of animal body plans and their later ecological success drives our current research.











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Biology Seminar

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October 22, 2015 4:00 PM  – 5:00 PM
Druckenmiller Hall, Room 020

Michael Mansour, M.D., Massachusetts General Hospital, Division of Infectious Diseases

Investigates the influence of fungal cellwall carbohydrates to the development of host immune responses. The fungal cell wall is composed of nearly pure carbohydrate recognized by a number of carbohydrate-recognition receptors on phagocytes such as macrophages, neutrophils and dendritic cells. Our research focus is two-fold.

1. Role of fungal carbohydrate recognition to the phagosomal protein repertoire and adaptive immunity. Following recognition, fungal pathogens are phagocytosed into newly formed organelles called phagosomes. We found that surface receptor recognition of fungal carbohydrates determines the recruited phagosome protein repertoire in macrophages including antigen-presentation machinery. In addition, we are exploring the role of fungal carbohydrates to other immune cell responses including neutrophils.

2. Prediction of fungal infection. We are investigating human responses to fungal carbohydrates as a prognostic indicator for IFI. The ability to "risk stratify" patients into low or high susceptibility for fungal infection will allow personalized clinical management therefore limiting the use of unnecessary diagnostics and anti-fungal drug side-effects.





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Biology Seminar

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November 5, 2015 4:00 PM  – 5:00 PM
Druckenmiller Hall, Room 020

Carrie Wu, Assistant Professor of Biology, University of Richmond

Investigates the mechanisms of adaptive differentiation and speciation. I am especially interested in how plants respond to their local environments, and the role those adaptations play in diversification at the genomic, population, and species levels. While evidence for local adaptation in plants is abundant, much less is known about the particular traits and genes that confer this specialization to specific environments. To this end, my research uses the wildflower genera Ipomopsis and Mimulus to examine how environmental variation influences phenotypic and genetic variation among natural plant populations. I combine observations of natural populations and experimental manipulations in the field and greenhouse with tools from quantitative genetics and physiological ecology. My projects take me to field sites in the northern Cascades in Washington, down through the Southern California foothills, and eastward to the Colorado Rockies. Together, these studies provide insight into how environmental stresses, adaptation to these conditions, and evolutionary change are intertwined, using tractable, ecologically relevant systems.











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Biology Seminar

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November 12, 2015 4:00 PM  – 5:00 PM
Druckenmiller Hall, Room 020

Ari S. Friedlaender, Associate Professor, Oregon State University, Marine Mammal Institute

Ari is an ecologist with a primary interest in the understanding the relationship between the foraging behavior of marine mammals and their prey. Ari works on a wide range of marine mammal species including baleen and toothed whales and dolphins across a range of geographic regions. Ari has long-term ecological research projects ongoing in Alaska, California, Massachusetts, North Carolina, and Antarctica. Ari has helped in the development of tag technology and analytical and visualization tools to better understand the underwater movements and behaviors of marine mammals. For his dissertation research, Ari used geospatial tools to quantify how the distribution of cetaceans related to environmental variables in Antarctica. At the MMI, Ari's lab will focus on developing new telemetry applications to elucidate the underwater behavior of marine mammals.

In Antarctica, Ari is part of the Long-Term Ecological Research program at Palmer Station to better understand the ecological roles of cetaceans in a rapidly changing environment. In Alaska and Massachusetts, Ari's research focuses on variability in the foraging strategies of humpback whales in relation to changes in their prey. In California, Ari is part of the SoCal Behavioral Response Study to understand the impacts of anthropogenic sound on a variety of cetacean species. Along with this research, Ari is an active member of the Society for Marine Mammalogy, acting as an associate editor for Marine Mammal Science and serving on the Conservation Committee. Ari is also a principal investigator in the Southern Ocean Research Partnership to conduct non-lethal research on cetaceans in the Southern Ocean.









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Biology Seminar

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November 19, 2015 4:00 PM  – 5:00 PM
Druckenmiller Hall, Room 020

Michael E. Hood, Associate Professor of Biology, Amherst College

My research addresses the ecological and evolutionary forces that shape systems of inheritance and the dynamics of disease in natural populations, both aspects of what could be called 'transmission biology.' In particular, I am working on how different genomic regions interact with an organism's reproductive strategy. Regions such as sex chromosomes, autosomes, and cytoplasmic components differ in their modes of inheritance and are therefore exposed to conflicting patterns of natural selection. At the same time, all of these regions are connected through their effects on individual fitness. My work addresses the resulting instability of genetic systems (at both individual and population levels), its proximal causes, and how some organisms cope or even adapt to genomic plasticity. I also have a long-standing interest in the biology of infectious diseases in natural populations. In many ways, host-pathogen interactions have conflicts of interest and instabilities that are analogous to those involved in the evolution of genetic systems. This is most clearly seen in the dynamics of "genomic parasites" (such as repetitive DNA elements or invasive mitochondrial types), but also in the general principles of horizontal transmission and co-evolution that allow antagonistic relationships to persist. Most of my current studies use the parasitic fungus Microbotryum, which causes anther-smut disease on plants of the Caryophyllaceae.





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NEURO Seminar

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December 3, 2015 4:00 PM  – 5:00 PM
Kanbar Hall, Room 107

Liz Chrastil, Postdoctural researcher, Boston University, Center for Memory & Brain Cognitive Neuroimaging Laboratory

I study human path integration, spatial memory, and large-scale navigation in complex environments. I have recently worked on projects using virtual reality to understand how humans encode distances and angles used in path integration. I have also investigated active and passive spatial navigation. In particular, I examined how proprioceptive input, vestibular information, decision-making, and attention contribute to landmark, route, graph, and survey knowledge. My current research ties in the neural correlates, with particular focus on breaking larger navigation tasks into smaller cognitive processes. I examine the relationships between these processes using fMRI.











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Biology Seminar

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December 3, 2015 4:00 PM  – 5:00 PM
Druckenmiller Hall, Room 020

Carla J. Essenberg, Assistant Professor, Biology Department, Bates College

Professor Essenberg is broadly interested in species interactions and in how mutually-beneficial interactions shape the ecology and evolution of their participants. In particular, she is interested in what governs variation in the benefits and costs organisms experience from their interactions. Work in her laboratory focuses on plant-pollinator mutualisms and uses a combination of field studies and behavioral experiments in the laboratory to address two major questions:

1) What determines whether plants will compete or cooperate in attracting pollinators?

2) What selective pressures shape the benefits and information plants provide to their pollinators?





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Sarah Schaak: "Understanding Mutational Dynamics Over Short and Long Time Scales"

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December 10, 2015 4:00 PM  – 5:00 PM
Druckenmiller Hall, Room 020

My two main interests are 1)  the rate, spectrum, and consequences of mutation in nuclear and organellar genomes and 2) the mobilome the most dynamic and exciting portion of the genome. 

 I am interested in the short- and long-term consequences of spontaneous mutation in terms of shaping the size, organization, and landscape of the genome. I am interested in the rate of mutation, and thus its impact on fitness, adaptation, the evolution of sex, and speciation in various environments. This is especially fascinating to me in eukaryotic systems, where gene products from multiple genomes (nuclear and organellar) must be compatible, even though the mutation parameters differ dramatically. Among the many types of mutation that occur, transposable elements are a source of some of the most dramatic genetic changes that we observe.  Mobile DNA (the collective term for selfish genes, jumping genes, transposable elements, mobile genetic elements, mobile introns, and many other types of DNA) can move within and between organisms, and can even cross species boundaries.  Further, pieces of mobile DNA can carry normally static DNA (hitchhiking) and can be amplified to high copy number in the genome. Often referred to as 'junk DNA', little is known about the impact of mobile DNA other than that it appears to account for a huge proportion of most multicellular eukaryotic genomes. Despite the importance of spontaneous mutation and the near ubiquity of mobile DNA, we have few empirical estimates of mutation rate and are only beginning to understand the genomic landscape of eukaryotes. The research in my lab is aimed at understanding the proximate and ultimate changes brought about by mutation, especially those caused by mobile DNA, at the genotypic and phenotypic level. Sarah Schaak, Assistant Professor of Biology, Reed College 

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