Fall 2013 Calendar

Informational Meeting for Prospective & Current Biology Majors

Informational Meeting for Prospective & Current Biology Majors

September 12, 20134:00 PM – 4:55 PM
Druckenmiller Hall, Room 020

A discussion for students interested in the Biology Major and current Biology Majors with concerns or questions.

Druckenmiller Hall Room 20

4:00 p.m.

View Details

Informational Meeting for the Biochemisty, Biology, and Neuroscience - Departmenal Honors

Informational Meeting for the Biochemisty, Biology, and Neuroscience - Departmenal Honors

September 19, 20134:00 PM – 4:55 PM
Druckenmiller Hall, Room 020

Informational Meeting:  A brief discussing on the guidelines for the Honors Program in Biology, Biochemistry, and Neuroscience

**Biochemistry students working with Biology Faculty.

Druckenmiller 20

4:15 pm

View Details

Disentangling environmental drivers of rocky intertidal seaweed ecology

Disentangling environmental drivers of rocky intertidal seaweed ecology

September 26, 20134:00 PM – 4:55 PM
Druckenmiller Hall, Room 020

Sarah L. Close, '06, Ph.D. Candidate, Department of Zoology, Oregon State University

My research focuses on how marine nearshore communities are shaped by the physical environment. In the California Current Large Marine Ecosystem coastal upwelling, bathymetry, and local factors interact to influence rocky intertidal communities in diverse ways and across different spatial scales. My research investigates the role of nutrients and light in marine macrophyte assemblage structure and function in order to further our understanding of how algal ecophysiology and nutritional ecology scale up to influence community dynamics. I approach this from a range of spatial scales, from small variations in tidal height on the order of meters, to large-scale variations in upwelling spanning hundreds of kilometers. Global climate change threatens to fundamentally alter physical patterns, such as temperature and pH, as well as processes, such as upwelling and sea level rise, in coastal oceans. Improving our understanding of the role these factors play in community dynamics is becoming increasingly important.

View Details

Tracing spider silk and venom evolution over deep time

Tracing spider silk and venom evolution over deep time

October 3, 20134:00 PM – 4:55 PM
Druckenmiller Hall, Room 020

Jessica Garb, Department of Biological Sciences, University of Massachusetts

Work in my laboratory is broadly aimed at understanding biological evolution, from the molecular level to species diversification. We specialize in spiders, one of the most species-rich animal groups, and our current projects largely concern the evolution of proteins that have enabled their proliferation. Spider silks are renowned for their impressive mechanical properties and exhibit tremendous functional variation within and across species. We are using genomic tools to characterize the polymer-like proteins that make up spider silks from a variety of species. Because these proteins are encoded by a gene family, phylogenetic analyses of spiders and the silk proteins they synthesize are used to trace the long and complex history of silk evolution. Another major project is focused on the evolution of venom from black widow spiders and their close relatives. We are determining the molecular composition of these venoms to investigate the origin and diversification of potent toxins that enable prey capture. Such evolutionary work facilitates the discovery of beneficial and hazardous toxins with biomedical significance.

View Details

Critical high-pCO2 exposure windows during early development of larval bay scallops

Critical high-pCO2 exposure windows during early development of larval bay scallops

October 10, 20134:00 PM – 4:55 PM
Druckenmiller Hall, Room 020

Meredith White, Bigelow Laboratory for Ocean Sciences

Increases in environmental pCO2 levels negatively affect growth and development in early life stages of many marine invertebrates, but it is not clear what processes are involved, nor which developmental stage are most sensitive. We investigated the effects of exposure to high CO2 during two different stages in larval development of the bay scallop Argopecten irradians: embryonic development prior to shell calcification (2-12 h post-fertilization), and initiation of shell calcification (12-24 h post-fertilization). We found that larvae exposed to high CO2 during initial calcification developed smaller shells than those in ambient conditions. In contrast, larvae exposed to high CO2 prior to shell-formation and calcification (2-12 h post-fertilization), developed an abnormal indentation in the shell, even if they were switched into ambient conditions afterwards, through initial calcification. Together, these results demonstrate two critical high-pCO2 exposure windows during bay scallop larval development, which produce negative, but distinctly different, effects on larval shell development.

View Details

Across-shelf mixing, larval transport, and the southern range boundary of the blue mussel

Across-shelf mixing, larval transport, and the southern range boundary of the blue mussel

October 17, 20134:00 PM – 4:55 PM
Druckenmiller Hall, Room 020

Phil Yund, Senior Scientist, Bigelow Laboratory

Across-shelf mixing, larval transport, and the southern range boundary of the blue mussel, Mytilus trossulus

Dr. Yund studies the evolutionary ecology of sessile and sedentary marine invertebrates as well as fertilization ecology, ecology of marine mammals, fish, and invertebrate pathogens.

Currently, he is conducting research in a variety of areas:
  • the hydrodynamics and fertilization in green sea urchins, Strongylocentrotus droebachiensis;
  • evolution of gamete compatibility, and processes determining range boundaries in blue mussels, Mytilus edulis;
  • dynamics of the discharge plume from the Saco River; and,
  • host affinity of Giardia and Cryptosporidium genotypes.

View Details

Daniel Schrag on Climate, Energy, and Innovation

Daniel Schrag on Climate, Energy, and Innovation

October 18, 201312:30 PM – 1:30 PM
Visual Arts Center, Kresge Auditorium

Common Hour with Dr. Daniel Schrag - Keynote for President's Science Symposium

Daniel P. Schrag will discuss "Climate, Energy and Innovation."

The increase in atmospheric CO2 due to burning coal, oil and natural gas represents an unprecedented experiment on the Planet Earth. Geologic records support the view that future climate change will have a profound impact both on human society and on natural ecosystems. A daunting challenge is the timescale of climate change. More than half of the carbon dioxide emitted to the atmosphere by burning fossil fuels will remain for hundreds of years, and roughly 20% will be there for tens of thousands of years. In this context, a variety of strategies will be discussed for meeting the world's energy needs, preserving economic prosperity and security, while protecting human and natural systems from climate impacts. In addition, we will explore what strategies might be required if the impacts of climate change are larger than we expect.

Daniel Schrag is the Director of the Harvard University Center for the Environment, the Sturgis Hooper Professor of Geology, and Professor of Environmental Science and Engineering at Harvard University. He currently serves on President Obama's Council of Advisors for Science and Technology. Among various honors, he was named a MacArthur Fellow in 2000. Schrag received a B.S. from Yale University and a Ph.D. in Geology from the University of California at Berkeley.

View Details

Carbon flux in symbiotic zoanthids under climate change and ocean acidification

Carbon flux in symbiotic zoanthids under climate change and ocean acidification

October 22, 20134:00 PM – 5:00 PM
Druckenmiller Hall, Room 020

Erin R. Graham, Department of Biology, Temple University

Many invertebrates in the phylum Cnidaria form endosymbiotic relationships with dinoflagellates (genus Symbiodinium), which supply their hosts with fixed carbon from photosynthesis. Symbiotic cnidarians form the foundation of diverse benthic ecosystems in tropical and subtropical waters, but rising sea surface temperatures and ocean acidification affect physiological processes in symbiotic associations, particularly calcification in reef-forming corals. Inhibition of calcification in corals suggests that future climate conditions may favor non-calcifying, soft-bodied cnidarians, yet there is little known about how climate change will affect carbon flux and primary production in non-calcifying symbiotic associations. Moreover, Symbiodinium species or types vary in their mechanisms of carbon acquisition, environmental tolerance, and photosynthetic output, therefore, symbiont type may alter carbon flux in the symbiotic animal (the holobiont).
In this seminar Erin will describe the effects of climate change and ocean acidification on carbon acquisition and fixation in two zoanthid species, and discuss mechanisms that may allow symbiotic cnidarieans to persist in warmer, acidified waters.

View Details

Rapid radiation, divergence, and sexual selection: population and phylogenomic case studies

Rapid radiation, divergence, and sexual selection: population and phylogenomic case studies

October 24, 20134:00 PM – 4:55 PM
Druckenmiller Hall, Room 020

Sarah Kingston, Smithsonian, National Museum of Natural History

Understanding speciation is crucial to the study of biodiversity. Unraveling the processes that govern the splitting and divergence of lineages is a tenet of evolutionary biology. Using three case studies Sarah will demonstrate the power of emerging technologies in population genomics and phylogenomics: a rapid radiation of species within a dolphin subfamily, divergence between towhee lineages in the face of hybrid-mediated gene flow, and introgression of a sexually selected plumage character across species lines in manakins.

View Details

Studies on the invasive ascidian Didemnum vexillum and the Long Island Sound Benthic Mapping Initiative

Studies on the invasive ascidian Didemnum vexillum and the Long Island Sound Benthic Mapping Initiative

October 29, 20134:00 PM – 5:00 PM
Druckenmiller Hall, Room 020

Lauren Stefaniak, Department of Marine Sciences, University of Connecticut

Over the past 40 years, the colonial ascidian, Didemnum vexillum, has spread from its native Japan to many temperate coastal regions of the world. Reproduction of daughter colonies in D. vexillum can be sexual, via larvae, and asexual, via long colony lobes or tendrils that easily fragment from the parent colony. Because D. vexillum broods its larvae within the colony matrix, in addition to having the potential to reattach and grow, detached tendrils could also transport competent or near-competent larvae to new locations. Here we quantify aspects of the life history cycle of D. vexillum to determine the relative importance of sexual and asexual pathways to D. vexillum reproduction. We found that the tendril growth form is important to the population biology of D. vexillum by increasing space for feeding and reproducing zooids in a space-limited environment. However, because reattachment of tendrils requires an extended period of contact, tendrils may primarily aid dispersal and establishment of new populations by increasing the number of recruits settling in a single location, potentially resulting in an increased probability of population survival.

The Long Island Sound Seafloor Mapping Collaborative is a multi-institution initiative to create new integrated ecological habitat maps of Long Island Sound. As a part of the Ecological classification group, my project uses a combination of a grab sampler equipped with high-definition video and still cameras, a remotely operated vehicle, drop cameras, and closed circuit rebreather diving to intensely sample benthic habitats. Along with acoustic benthic imaging, modeling of the physical environment, and sediment characterization, these observations will be used to generate habitat maps that managers and stakeholders can use to plan infrastructure in Long Island Sound in a way that minimizes impacts on economically important fisheries and the ecological health of the Sound.

View Details

Cellular Supply Chain Management: RNA-based Control of Ribosomal Protein Synthesis in Bacteria

Cellular Supply Chain Management: RNA-based Control of Ribosomal Protein Synthesis in Bacteria

October 31, 20134:00 PM – 4:55 PM
Druckenmiller Hall, Room 020

Michelle Meyer, Assistant Professor of Biology, Boston College will speak about her research on "Cellular Supply Chain Management: RNA-based Control of Ribosomal Protein Synthesis in Bacteria."

Meyer's fields of interest include computational biology, non-coding RNA discovery and validation, molecular evolution, RNA and protein structure.

View Details

Environmental drivers of spatial biodiversity patterns from genomes to communities

Environmental drivers of spatial biodiversity patterns from genomes to communities

November 7, 20134:00 PM – 4:55 PM
Druckenmiller Hall, Room 020

Biology Fall 2013 Honors Seminar

Jesse Lasky, Columbia University
 
Spatial variation in communities and populations is one of the oldest recognized, yet least understood patterns in biology (see von Humboldt & Bonpland 1805, at right). I am fascinated by the challenge to understand spatial variation in complex ecological systems, partly because predicting changes in biodiversity in response to environmental change can inform conservation planning. My interest in fundamental ecological and evolutionary processes has led me to study biology at the levels of communities and genomes. Though seemingly disparate, the two systems are mathematically similar in that they are highly multivariate, which challenges attempts to understand drivers of diversity. I study individual-scale processes with large data sets and advanced computational tools in order to make inferences about large-scale biodiversity patterns.

View Details

Germ cell immortality and totipotency in C. elegans

Germ cell immortality and totipotency in C. elegans

November 21, 20134:00 PM – 4:55 PM
Druckenmiller Hall, Room 020

C. elegans P granules: a genetic model for understanding cellular immortality and totipotency in the germ line

No individual organism lives forever, but its genes and traits may be passed along from generation to generation thanks to its germ cells. Germ cells are the progenitors of sperm and eggs, and the ability of any species to perpetuate itself depends on the ability of its germ cells to give rise to all the cells of each subsequent generation. That ability – the capacity of a cell to become, by dividing and differentiating, any and all parts of a given organism, including the next generation of germ cells – is called “totipotency.” It’s an extraordinary property that essentially confers immortality on germ cells. 

What makes germ cells totipotent? My lab studies small aggregates called “germ granules” that are found just outside the nucleus of germ cells. Recent research has shown that germ granules play a critical role in maintaining the totipotent and immortal properties of the germ cell line. 

Our lab uses the small roundworm C. elegans as a genetic model to understand germ granule function across species. Using these worms, we are able to determine the genetic components responsible for germ granule assembly and localization, their biophysical properties, and how they function in germ cells. Because germ granules play a role in cellular self-renewal and pluripotency, germ granule research not only impacts the field of reproductive biology, but will also add a new dimension to ongoing efforts in the field of regenerative medicine. 

View Details

Dopaminergic regulation of sleep, arousal, and attentional processes

Dopaminergic regulation of sleep, arousal, and attentional processes

December 5, 20134:00 PM – 4:55 PM
Druckenmiller Hall, Room 020

View Details

"The evolution of complexity in animals"

Unknown Image

January 23, 20144:00 PM – 5:00 PM
Druckenmiller Hall, Room 020

Biology Department Weekly Seminar Series


CASEY DUNN, Assistant Professor of Biology, Dept. of Ecology and Evolutionary Biology, Brown University

The Dunn Lab investigates how evolution has produced a diversity of life. We primarily focus on form (i.e. morphology), and are interested in learning about both the actual history of life on Earth and general properties of evolution that have contributed to these historical patterns. The type of questions the Dunn Lab asks require field (mostly marine), laboratory, and computational work.

View Details