EVOLUTION

youngbeagleold

Nothing in biology makes sense except in the light of evolution.
- Theodosius Dobzhansky

 

LINKS TO: ASSIGNMENTS, READINGS, CLASS NOTES

EVOLUTION, BIO4104, Spring 2019, 4 credits, M-Th, 8:0-9:50 AM, Dickinson 117
Kerry Woods
(Dickinson 144, 440-4465, kwoods@bennington.edu, office hours Tues, Wed, Fri 10-12)

Life is interesting because of its adaptive (and maladaptive) diversity and complexity.  Evolutionary theory is the only available explanation  for these properties that's both fully testable and consistent with the evidence on hand -- the essential properties of any legitimate body of science.  The great theories have the additional quality of 'fertility'.  They not only address questions we're already thinking about, but they suggest new connections and consistencies across bodies of theory and understanding -- they generate new questions and ideas.  Evolutionary theory has been, and continues to be, extraordinarily fertile across fields ranging from geology to anthropology and psychology.

Darwin didnít invent the idea of evolution, but his insight into its mechanisms and his formulation of the concept of natural selection constitutes one of a handful of true revolutions in science.  Equally importantly, he was one of the first scientists to be recognizably 'modern' in his approach to framing and assessing hypotheses. The modern consensus on evolution, growing from many decades of rigorous assessment and testing (and controversy), continues to embody most of Darwinís ideas at its core. However, much has been added, especially through discoveries in genetics and advances in modeling, and much remains to be understood.  Evolutionary biology is a dynamic science; discussions and debates are lively, and important new studies are published frequently.  

This course will explore current understanding of the mechanisms and patterns of evolution at the population/gene-pool level. While the basic selective process is an inescapable logical consequence of properties essential to what we call 'life', many of the implications and predictions of selective theory are deeply counter-intuitive (perhaps because our intuition has been shaped by selection) and challenging. We will focus on the workings of selection in populations as it shapes adaptations and life-histories.  In-depth exploration of the grand history and diversification of life Ė phylogeny and biogeography Ė is another class.

Why are organisms so diverse? Some are very complex, while others have become highly simplified; why? What is the cause and significance of the similarities and differences we observe in the properties and behaviors of different types of organisms? If individual (or gene-level) fitness differences drive selective evolution, how do we understand the existence of properties and behaviors like sexual reproduction, cooperative behavior? Can deep understanding of selective evolution contribute to human well-being? Are there trends in evolution? How does one study evolution? In addressing these and other questions we will read and discuss, in additional to a general text, primary research papers and essays.

EXPECTATIONS and EVALUATION

I expect you to take this course seriously. You must attend class and keep up with assigned readings; otherwise, you'll get lost and confused or the entire class will be slowed. If an absence can't be helped, let me know beforehand if possible, but you must bear the responsibility for catching up (first, make sure you're caught up on any assigned reading, then talk to another class member to review what happened in the missed class; then come to me with any questions you have).  Too many absences (no set number -- what's too many depends a lot on you -- but more than three or so often makes for challenges) can be reflected in evaluation and may lead to failure.

Attendance and formal completion of assignments is not enough to do well.  Give serious thought to the subject matter, participate in the discussion, exercise your capacity for critical thought, and take responsibility for pursuing your own questions and interestsChallenge yourself and bring the resulting thinking to class.  If you do nothing but come to class and complete the assigned reading and writing, you're not really doing this! 

Written assignments must be completed and on time: late assignments may not be accepted without prior arrangement, and late work can affect your evaluation.  Missing or consistently late work may lead to failure.

I also expect you to enter the class with a working familiarity with some of the basic processes and vocabulary of biology.  In particular, it's important that you have a basic grasp of the cell cycle (meiosis, mitosis), of the basic structure of DNA and proteins, and of the processes of DNA replication and translation. These are all essential to clear thinking about selective processes (as well as general understanding of modern biology and its significance in your lives) and will be assumed in this class.  Here's a very brief list/review of some important terms and concepts; if they are not reasonably familiar/comfortable, you may need to do some background review -- talk to me about it.  You will also need some basic algebraic skills to work with some of the models and fitness problems we'll be looking at.  We won't go anywhere more difficult than solid high-school-level algebra here, but modern evolutionary biology is highly quantitative and relies heavily on mathematical modeling.

Evaluations will be based on all aspects of performance, including contributions to class discussion; if you request a letter grade, anticipate that essays and other written exercises/problem-sets  will each account for about 40% of your grade; the remaining 20% will be based on other aspects of class participation.

WEB SITE

All assignments as well as other information pertaining to the class will be posted through links from this website (see top of page).

REFERENCES

Crosset library has good digital access to primary research journals that bears on evolution as well as an interesting selection of pertinent books. To find papers on topics of interest and for review essays, you can use the library's data-bases (from the Crossett Library web-page), but, increasingly, sources like scholar.google.com can offer greater power and scope -- BUT call for skillful search strategies.  Google scholar does a pretty good job of finding pdf's of papers available through library or other sites, but I also recommend apps like 'unpaywall' (a browser plug-in) that can help find accessible copies of papers that are on subscription-only journals.  We'll talk about these tools in class.  You'll be expected to find, read, and review several papers over the course of the term.  

BUT ALSO consider simply going to journals' websites and browsing current issues; this is the best way to get acquainted with what's going on in a field and to find interesting papers, questions, ideas.. Almost any biological journal will publish papers addressing evolutionary questions, but here are some that are particularly likely to have appropriate papers for your review essays:

American Journal of Botany
American Naturalist
(lots of theory, some with relatively advanced mathematics)
Behavioral Ecology and Sociobiology
BMC Evolutionary Biology
Proceedings of National Academy of Science
(many disciplines, but generally a few 'cutting-edge' articles on evolution)
Ecology (need to select evolutionarily oriented papers)
Evolution (obviously)
Journal of Evolutionary Biology
Nature (this one and next usually have one or two evolution-oriented papers; they tend to be shorter, more 'telegraphic' than others. May not be as complete as to methods, background, but generally have the hottest stuff.)
Science
PLOS ('public library of science'; freely accessible on-line)

TENTATIVE COURSE OUTLINE

This outline may change as things progress. Readings are from Evolution: Making Sense of Life  by Carl Zimmer and Douglan Emlen; I donít care whether you purchase the book, but you should make sure you have reliable access to it (or some other solid evolutionary biology text/reference; ask if you want to know if one's appropriate).  This is a recent text: Zimmer is a highly respected science writer and Emlen is at the forefront of evolutionary biology research.  We won't 'cover' text material  sequentially or completely, but I indicate chapters that are pertinent to general topics in the outline below.  Read those chapters in advance of class and bring questions to class: that'll alow us to forego much "lecturing" in favor of questions and discussion. Additional readings from primary sources will be assigned regularly. Some chapters won't be particularly addressed in class, but feel free to read them (they are interesting) and bring questions to class.

I. Introduction and Context (READ Chs. 1-2)
- What's evolution? Natural selection, adaptation, exaptation
- Origins of the idea, history of hypotheses
- Evidences of evolution; can it be studied scientifically?
- Inheritance, genetics, and inevitability
- Characteristics of genes, organisms, populations, species

II. Processes and Mechanisms: basic selective theory (READ Chs. 5-8)
- Variation and its origins
- Population structure and genetics
- Non-selective evolution
- Natural Selection and adaptation

III. Life-history evolution (READ Chs. 10-12,15)
- Life history evolution
- game theory, optimality, and stability
- Coevolution, parasitism, and symbiosis 
- Kin selection, sociobiology, altruism, and selfish genes
- What good is sex?
- Sexual selection

IV. Evolutionary applications.  Lots of possible topics; evolution of disease/evolutionary medicine, evolutionary biology and conservation, plant and animal breeding, ect... (READ Ch. 16-18)

V. Bigger pictures: Origins and patterns of diversity (we MAY get into this stuff...)
- Speciation (READ Ch 13)
- A brief intro to phylogenetics and evolutionary biogeography (READ Chs. 14)


-- KDW, Feb 2019