Theoretical Ecology Lab Tea

The Theoretical Ecology Lab Teas are informal meetings where members of affiliated lab groups give talks on their current research and receive feedback from their audience. The talks are 30 minutes (20 minutes of presentation and 10 minutes of questions) and are scheduled generally on Wednesdays at 12:30 pm. All talks this semester will be held in Eno 209 unless stated otherwise.

This semester, talk schedules and email lists will be maintained by Rutwik Kharkar and Olivia Guayasamin. Please contact one of us to have your name added to the labtea email list so that you can receive reminders about upcoming meetings.

Spring 2016 schedule

Date and time Speaker
Matthieu R. Barbier
Elise M. Myers
Sarah Drohan
Michael Price
Olivia Guayasamin
Charlotte H. Chang
Matt Grobis
Adam F. Pellegrini
George W. Constable

Note: Priority is given to graduate students. A symbol next to the speaker's name means that approval is pending for a week and graduate students can still claim the slot.

Titles and abstracts

The Pig, the Fish, and the Capital Matthieu R. Barbier

This lab tea is about human economic attitudes towards non-humans, how they are constructed and transformed, and why Papuan pig exchanges have a lot to tell us about how to theorize it all.

Many empirical facts, especially of the "soft" socio-psychological kind, appear fairly regular after a change of modeling mindset. To overstate a little: agents have no preferences, norms are not meant to curb human nature, and many of the cognitive biases in behavioral economics are actually not biases at all. I have attempted to elaborate this framework-in-progress around stylized examples from Melanesia and the North Atlantic. I would appreciate some critical input, especially as it slowly evolves toward applicability.

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Exploring Syntrophic Relationships between Sulfate Reducing Bacteria and Methanogens Elise M. Myers

Cooperation and competition among microorganisms in microbial communities is essential to study, especially in order to improve our understanding of how microbes act in natural systems, function as a unit, and respond concurrently to environmental changes. Microbial flexibility, the ablitiy of microorganisms to utilize different metabolic pathways than their "preferred" pathway (espectially in anoxygenic environments), can support cooperation as microbes shift to more energetically favorable, cross-microbial redox coupling for their metabolism. In particular environmental conditions, these microbes enter into syntrophy, an obligate dependency where the metabolism of each microbial type relies on the metabolites produced by the other microbial type.

In my current work, I am exploring the relationship between methanogens, which release hydrogen, and sulfate reducing bacteria (SRB), that can use the hydrogen as an electron donor, resulting in overall exergonic (energy releasing and, thereby more energetically favorable) reactions for both microbial types. I have created a basic framework for a cooperation based mathematical model of the differential syntrophic relationships that are possible between SRB and methanogens. The different cases I am simulating are defined by the following environmental conditions: 1) abundant resources for both microbial types, 2) abundant resources for methanogens only, 3) scarcity of resources for both microbial types. By examining these three test cases, I hope to help elucidate how complex dependencies (including syntrophy) can develop, what environmental conditions trigger these dependencies, and how different levels of co-dependence between microbes impact the population dynamics of these communities. Initial simulation results suggest this model can generally predict population dynamics, though I hope to increase precision by modeling the shuttling of metabolites between the microbial types.

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The Evolution of Mammalian Life Histories in Non-Stationary Populations Michael Price

We describe a novel allometric model of the evolution of mammalian life histories that extends work by Charnov and colleagues. Charnov's model combines three basic components: (1) a growth production function that links growth in body size to body size, (2) natural selection on age at first reproduction, and (3) stationary demography (i.e., a constant population size). Our extension combines four basic components: (1) an arbitrary growth function, (2) natural selection on age at first reproduction, (3) non-stationary demography, and (4) natural selection on size at independence. The three key differences are thus (a) an arbitrary growth production function, (b) non-stationary demography, and (c) optimization over size at independence (in addition to age at first reproduction). Charnov's model fixes the ratio of size at independence to size at first reproduction, but work by Purvis and Harvey shows that there exists considerable variability in this ratio across mammal species. Furthermore, the ratio correlates with other life-history traits, which our extension can explain since we model natural selection on size at independence.

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Charlotte H. Chang

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Matt Grobis

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Adam F. Pellegrini

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George W. Constable

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Links to previous schedules

  1. Fall 2000
  2. Spring 2001
  3. Fall 2001
  4. Spring 2002
  5. Fall 2002
  6. Spring 2003
  7. Fall 2003
  8. Spring 2004
  9. Fall 2004
  10. Spring 2005
  11. Fall 2005
  12. Spring 2007
  13. Fall 2007
  14. Spring 2008
  15. Fall 2008
  16. Spring 2009
  17. Fall 2009
  18. Spring 2010
  19. Fall 2010
  20. Spring 2011
  21. Fall 2011
  22. Spring 2012
  23. Fall 2012
  24. Spring 2013
  25. Fall 2013
  26. Spring 2014
  27. Fall 2014
  28. Spring 2015
  29. Fall 2015