Science Workshop, 5 April: Before Animals: The Co-Evolution of Earth and Life in Deep Time

Fieldwork in the Neoproterozoic

Professor Phoebe Cohen of the Geology Department at Williams College will speak at Science Workshop on Friday, 5 April, at 1:00 pm in Dickinson 225.

Her work combines microscopic and microchemical techniques with field-based stratigraphy and sedimentology to reconstruct ancient organisms and ecosystems.  She will discuss her research in the context of our current knowledge about the evolution of life during the Neoproterozoic time period — the ~500 million years of Earth history before the rise of animals. While the sudden appearance of animals in the fossil record is dramatically demonstrated in the Cambrian radiation, the groundwork for animal evolution, and the co-occurring changes in marine ecosystems and ocean chemistry, were laid during the Neoproterozoic. Studies of the dynamic earth-life system in deep time present special challenges, but are transforming how we think about biology and geology.

Here are links for a) a paper for background on evolution in the Neoproterozoic, and b) a paper presenting some of Dr. Cohen’s research.

Students interested in having lunch with Dr. Cohen before her talk should be in touch with Kerry Woods.

Science Workshop 29 March — Long-term studies, ecological baselines, and the way things ought to be:

old-growth

A high-biomass old-growth stand of eastern hemlock in northern Michigan

After decades of studying ancient forests, we’re less confident of what we know about them than we were thirty-five years ago.  For the last 20+ years I’ve been working with long-term permanent study plots in old-growth forest in Michigan.  I began with the hope that an exceptionally deep data-record would allow me to test hypotheses about mechanisms behind equilibrial dynamics.  Now I’m convinced that our initial assumption — that these ecosystems represented a sort of steady-state, climax ‘baseline’ — was flawed, and the natural landscape is much more dynamic than we imagined.  If that’s the case, what are the implications for concepts of nature conservation and ecological restoration?  What is to be conserved or restored if there’s no detectable natural baseline condition?

I will review about the findings of my old-growth research with a focus on new results, talk about  some new work using new technologies to try to understand whether these forests are carbon sources or sinks, and wind up with some exploration of what this all means for forest conservation priorities under climate change, Pleistocene rewilding, and the cloning of extinct species.

A sweet story of glycoprotein maturation and quality control in the early secretory pathway

Dr. Dan Hebert from the Department of Biochemistry and Molecular Biology at The University of Massachusetts, Amherst will join us for science workshop on Friday, March 22nd.  Dr. Hebert’s laboratory studies the mechanisms underlying the folding, maturation, and, if need be, degradation of proteins as they enter and traverse the endoplasmic reticulum.  An important part of this process, for many proteins, is the addition and modification of sugar residues (aka glycosylation) that are important for the final folding, sorting and/or function of the protein. When this process is defective, or if other problems arise during protein folding, detection and elimination of the misfolded protein is critical for cell viability. Dr. Hebert will give us an overview of the process of ER folding and quality control and discuss recent contributions of his laboratory to this sweet field of study.

 

Better late than dead: Mechanisms and consequences of early freshwater entry by Fraser River late-run sockeye salmon

The Fraser River is the most productive salmon river in Canada, and sockeye salmon are the most economically important salmon in the watershed. Prior to 1996, populations of the Fraser’s late-run sockeye complex were unique in that upon arrival in the Strait of Georgia they milled within the estuary for several weeks prior to entering the Fraser and proceeding to spawning grounds. Since 1996, large proportions of late-run sockeye have entered the Fraser without holding in the estuary, resulting in pre-spawn mortality rates upwards of 95% for early-entry fish. Causes for the mal-adaptive shift in freshwater entry timing are unknown. In 2002, we initiated a multi-year interdisciplinary (ecology, physiology, oceanography, genomic) research program to explore the causes and consequences of early entry. We combine field collections, experimental manipulations, and telemetry tracking studies to test how individual physiological condition corresponds with timing of river entry and ultimate fate. Initial findings indicate early entry late-run sockeye are characterized by unusual ionic, osmotic, and energetic states, and that advanced sexual maturation appears incompatible with survival in marine waters. Our efforts should yield a predictive model of sockeye migration behavior and survival, which should enable resource managers to optimize management and conservation of these important runs.

Fish ecologist, Dr. Michael Cooperman of Conservation International will discuss his research on Sockeye salmon during Science Workshop, Friday, Mar. 15, Dickinson 225, 1:00 -2:00 pm.  Dr. Cooperman is also involved in fish conservation in Cambodia. All are welcome.

 

Science Workshop Friday March 8 – How to study processes in the lower crust

To find the right rocks, sometimes you need to go to out-of-the-way places

Xenoliths (foreign rocks) are pieces of rock that were brought from the lower crust or upper mantle by ascending magma. Xenoliths occurrences are one of the few places that we can obtain samples from this zone, and therefore provide some of the only insights into the places where a lot of the geologic phenomenon that we see at the surface actually happens. Tim Schroeder has been studying xenolith-rich lava deposits in Arizona, and will share some insights into what can be learned about the history of western North America from a few tiny little bits of rock.

Xenoliths in a lava outcrop in Chino Valley, AZ

ASSC 17 San Diego: July 12-15, 2013

Volunteer Opportunities: The 17th Annual Meeting of the Association for the Scientific Study of Consciousness (ASSC17), San Diego, CA, July 12-15, 2013

The ASSC is the preeminent scientific association dedicated to promoting and disseminating the study of that most complex–and mysterious–of brain functions: consciousness. Every year, ASSC members from the ranks of neuroscience, psychology, medicine, and philosophy meet to present and discuss the latest findings in the young, but growing, field of consciousness research.

This year, the Scientific Program Committee will be judging abstracts for papers and posters after March 22nd (the submission deadline, which will likely be extended until April 1st). However, an exciting roster of keynote speakers, symposia, and tutorials is already planned (check out http://theassc.org/assc_17 for details).

The Co-Chairs of ASSC 17–David Edelman and Tobias Schlicht–are looking for a few enthusiastic students to work as volunteers during the meeting. So, if you’re fascinated by the problem of consciousness and would like the opportunity to mingle with an exciting mix of cognitive scientists, neuroscientists, clinicians, and philosophers, and hear about the cutting edge in consciousness research–all in exchange for about 4 hours of work per day–please contact David Edelman for details.

For more information about the ASSC and the 17th Annual Meeting, please check out http://theassc.org.