Week 1
January 15 Introduction
to the Course
We begin with a first look at the theories of A.I. Oparin, the Russian biochemist who began the scientific study of abiogenesis early in the 20th century. His basic concepts form the theme of the course, although the specifics of his proposals are often debated.
Week 2
January 20 Abiogenesis
We begin the study of abiogenesis [life from non-preexisting life] by looking at the first two steps in the process: the abiogenic synthesis of monomers and, polymerization. Reading:EE chapter 5 (Lazcano).
January 22 Evolution
of the first living system
Oparin's theory provides a framework for discussing self-assembly of the first cells and the interface between non-living and living systems. Once living systems exist, they evolve through the Darwinian mechanism of Natural Selection.
Week 3
January 27 The Rock Cycle
The origins of life is very tightly linked with the active chemistry of the Earth's suface. In this lecture we take a quick look at the dynamics of Earth systems and a 5 billion year planetary history.
January 29 Earth Origins
The planetesimal or accretion theory for Earth's origin is important for constraining the range of possible components available for abiogenesis. Much of what we know of the conditions on early Earth comes from the study of meteorites and the study of nearby planets. How do we know how old Earth really is? We introduce the basic methods that geologists use to date rocks.
Week 4
February 3 Relative and Absolute Geologic Time
The historical development of the geological timescale and the principles of Stratigraphy. Introduction to radiometric dating methods.
February 5 Grand Cycles in Earth History - QUIZ #1
Secular vs. cyclic change in geological systems. Amadeus Grabau and grand geological cycles. Plate tectonics and the Wilson Cycle. Reading:EE chapter 10 (Seiver).
Week 5
February 10 Chemical Evolution I
The abiological synthesis of organic precursors to biomolecules could have occurred on the early Earth. Or were they generated in space and transported here in comets and meteorites? We examine the evidence for Earth's earliest environments and the abiological synthesis of simple organic compounds. Reading: EE chapter 5 (Lazcano).
February 12 Chemical Evolution II
The synthesis of monomers. What kinds of chemical reactions could have produced simple organic compounds? Are these chemical reactions compatible with what we know about initial conditions on the planet? We review the research in this field, starting with a very famous experiment by Stanley Miller in 1953.
Week 6
February 17 Polymerization: the generation of macromolecules
The organic molecules that are used to build living systems are mostly polymers, larger molecules made up of smaller subunits. Nucleic acids, lipids, complex carbohydrates and proteins all fit into this category. The mechanisms and environments that supported the genesis of such molecules is an active area of origins research today. Reading: EE chapter 3 (Matthews).
February 19 RNA and DNA: The origins of the genetic system
Nucleic acids play a special role in living systems because they contain the genetic information that is encoded and passed on from organism to organism. How did the genetic code get started and how has it evolved?
Week 7
February 24 Cellular metabolism and photosynthesis
Living organisms depend upon the packaging of life into membrane-bound units called cells. All cells use energy in ways that are common throughout life. How do cells manipulate and control the chemical energy that is contained in certain molecules? We explore the origins of photosynthesis and related mechanisms for creating food from inorganic sources. Reading: EE chapter 8 (Margulis).
February 26 Self-Assembly: The bugaboo of abiogenesis QUIZ #2
This is where Oparin's theory is weakest - we are long way from understanding how a collection of molecules can assemble into a living system. We explore some of the different directions this topic holds at the present time, from materials science and physics to experimental attempts to build actual cells. Reading: EE chapter 4 (Deamer).
Week 8
March 10 Darwinian Evolution
Once a primitive living system was up and running on Earth, the Darwinian process of Natural Selection provides a well-studied basis for subsequent evolution and development of life.
March 12 Darwin Assignment
Week 9
March 17 The Archaean fossil record.
We survey the fossil record for earlist life on Earth. This includes direct evidence of prokaryotes, indirect chemical evidence and trace fossils. Reading:EE chapters 6 (Strother& Barghoorn).
March 19 The Proterozoic fossil record.
The record of life during the Proterozoic is based on unequivocal microfossils preserved in cherts and in siliciclastic sedimentary rocks. We survey the kinds of fossils, including chemical fossils and biomarkers, that characterize the later half of Precambrian time. Reading:EE chapter 9 (McMenamin)
Week 10
March 24 Stromatolites: A modern analog of Precambrian Earth. - QUIZ #3
Stromatolites are organo-sedimentary structures that trap and bind sediment constructed by communities of mat-building microorganisms. origin some 3 Gyr ago is pretty strong evidence for the origins of life by that time. They exist today in the Bahamas and in Western Australia. Reading: EE chapter 7 (Golubic).
March 26 Life during Ediacaran time.
The organisms that lived during the end of Precambrian time were very different from those that rose to dominance during the Phanerozoic. This lecture surveys the creatures found during the Ediacaran Period as we attempt to comprehend their functional biology. Reading:EE chapter 9 (McMenamin).
Week 11
March 31 Phanerozoic diversity.
We take a brief look at the pattern of increasing diversity of life on Earth over the last 542 m.y. This pattern is greatly affected by environmental and climatic changes over millions of years in combination with evolutionary responses by species to local biological and environmental factors.
April 2 Terrestrial Ecosystems.
We look at the origin and evolution of plant life on land and the effects this has had on the changing Earth.
Week 12
April 7 Earth History and Climate.
The record of past climate change can be traced back in time, but the techniques and methods to do so vary greatly as one proceeds deeper and deeper into the geologic past, from the Ice Ages that receded only 8,000 years ago in New England to the "SnowBall Earth" hypothesis of a totally frozen planet during the late Precambrian.
April 9 (no class)
Week 13
April 14 Evolution of the atmosphere. - QUIZ #4
Changes in O2 and CO2 throughout Earth history have had (and are having) profound effects on all life on Earth. We review the geological evidence that documents these changes over time and discuss the impact they have had on the origin and evolution of life on Earth.
April 16 Evolution of the oceans.
Until just a few years ago, the history of the composition of the oceans was considered to be essentially unchanged through geologic time. A new paradigm of alternating aragonite and calcite seas has now taken hold.
Week 14
April 21 Gaia Hypothesis
James Lovelock and Lynn Margulis formulated the Gaia Hypothesis to help emphasize the importance of biological processes that influence the composition of the reactive gasses in Earth's atmosphere. The Gaia Hypothesis is often misunderstood to be more of a social phenomenon, but we will use it as a means to study the interaction between life and the Earth's life-sustaining environment. Reading: EE chapters 1 (McElroy) &16 (Lovelock).
April 23 S.E.T.I. and Exo-solar Planets
The Greenbank Equation is a generalized calculation about the probability of life elsewhere in the Universe. The search for extraterrestrial intelligence has received a boost in recent years with the continuing discovery of planets outside our own solar system.
Week 15
April 28 The Search for Life on Mars I. - QUIZ #5
The early Viking experiments and ALH84001.
April 30 The Search for Life on Mars II.
Evidence of water and sedimentary rocks on Mars today.
Lecturer: Paul Strother, Lecturer
Teaching Assistant: Josh Coefer
Email: strother@bc.edu, please use "GE146" in the subject header.
Office telephone: 617 552-8395 or 617 552-1967
Office Hours: 11-1 pm Tuesdays and Thursdays, or by appointment.
Environmental Evolution (2nd ed.) by Margulis et al. (eds.). MIT Press. EE.
On the Origin of Species by Charles Darwin.
Any additional reading assignments will be announced in class.
1. a series of 5 Lecture Quizzes (60%),
2. an in-class Darwin Assignment (10%), and,
3. your lab section grade (30%).
All quizzes are "open notes" exams, which means that you may use your class notes, or any additional notes that are originally created by you.
The Darwin Assignment will take place in class and will be similar to a quiz except that it will be based on your reading of the Origin of Species.
update: February 19, 2009