The Evolution Of Life From The Anaerobic To The Aerobic World

Principal Instructor: David Catling, Rm. 422, ATG Building, dcatling@u

T,Th 10.30-11.50am, F 10.30-11.20am, Rm. 406, ATG Building

OVERALL DESCRIPTION

The most significant era in Earth's biological and geological history is the Paleoproterozoic (2.5-1.6 billion years ago). It is marked by the appearance of the first fossils visible to the naked eye, the diversification of aerobic eukaryotes, the possible loss of anaerobic lineages of microbes, a world-wide spread of intracontinental rifts, dramatic climate change with putative "Snowball Earth" glaciations, the formation of an oxygenated atmosphere, the development of the most significant positive ¹³C/¹²C shift of sedimentary carbonates in Earth's history, a vast accumulation of ¹³C-depleted organic material, and a flood of sulfate to the ocean. Yet all these events remain poorly understood. We will review current research on the transition from the anaerobic to aerobic world. We will conclude by moving from microbial metabolism to global-scale thermodynamics. We will examine the global bioenergetic change with the rise of oxygen, which allowed life to exist in states of lower entropy.

Week	Session		Faculty lead
1	Geological and Biogeochemical Change in the Paleoproterozoic		Roger Buick
	I	Geologic Indicators of the Rise of Oxygen
	II
	III	Research Paper Discussion: Student debate on the Rise of Oxygen
2	I	Paleoproterozoic Biology
	II
	III	Research Paper Discussion: Earliest Evidence of Cyanobacteria?
3	I	Isotopes & Global Change
	Atmospheric Change and “Snowball Earth” at 2.4-2.2 Ga		David Catling
	II	The Archean-Proterozoic Atmosphere
	III	Research Paper Discussion: A deeply sulfidic Proterozoic ocean?
4	I	Mass-Independent Isotope Fractionation (MIF) in Sulfur
	II	The Rise of Oxygen: Why and How Did It Happen?
	III	Research Paper Discussion: How does MIF work?
5	I	Paleoproterozoic Snowball Earth: Theory and Evidence
	II
	III	Research Paper Discussion: Snowball Earth or hailstorm of hype?
6	Evolution of Microbial Metabolism: From Anaerobes to Aerobes
	I	Anaerobic Metabolism I: Methanogens	John Leigh
	II	Anaerobic Metabolism II: Sulfate reduction	Dave Stahl
	III	Research Paper Discussion	All
7	I	No Class: Veteran’s Day Holiday	N/A
	II	Anaerobic Metabolism III: Anaerobic Photosynthesis	Jim Staley
	III	Research Paper Discussion	All
8	Bioenergetics and Entropy in an Anerobic vs. Aerobic World
	I	From Anaerobic to Oxygenic Photosynthesis	Jesse Dillon
	II	Energy and Metabolism Thermodynamics	David Catling
	III	Research Paper Discussion
9	I	Oxygen, Metabolism, and the Size of Life
	II,III	No Class: Thanksgiving Holiday	N/A
10	I	Entropy in Physics vs. Entropy in Information Theory	David Catling
	II	Linking it all together: Life and Entropy
	III	Research Paper Discussion
11	Student Paper Presentations

GRADING:

Students should select a topic to review for a term paper by the end of week 5. This written paper will be marked and will also be presented orally by the student in Week 11.

During research paper discussion sessions, students will be asked to present at least one research paper. This part of the course is graded to ensure well-prepared presentations.

Finally, the instructor will give out one homework problem set in Week 9 on metabolism thermodynamics, life and entropy.

Research Paper Discussion: 15%

Written term paper: 60%

Presentation of term paper: 15%

Homework: 10%

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