Grading (revised)

Grading (obsolete)

The large projects will involve reading of the primary literature and analysis of some associated data. You will be asked to prepare a 4-5 page written summary of your conclusions and to present details of your data analysis. The small problems will involve analysis and interpretation of smaller data sets. You will be asked to write a 1-2 page summary of your analysis and interpretation. I encourage you to work together on projects. Even though you will be graded individually on the projects, you are likely to find that discussing possible approaches and interpretation with your classmates will be a great help in clarifying your thinking.

In addition to graded problems and projects, I expect to provide some practice problems. These aren't to be handed in or graded, but they will provide practice on the types of questions you'll encounter in the problems and projects. Working through the practice problems will help you apply the concepts you'll need to know well for your projects.¹

Course description

This course is an introduction to the field of population genetics, the branch of evolutionary biology concerned with the genetic structure of populations and how it changes through time. Some of us see population genetics as the core discipline in evolutionary biology, since changes in the genetic composition of a population are the basis for all other evolutionary change within lineages.

There are two aspects of this course that sometimes cause students problems.

1. Geneticists think differently from most other biologists (and most other human beings, for that matter). They love monohybrid and dihybrid crosses, linkage, penetrance, dominance, and the like. We population geneticists are even worse. To explain things that you can see with your bare eyes, like phenotypic differences among individuals, we intoduce abstract concepts, like additive genetic variance, that are pure statistical artifacts that no one can see. By the time you finish this course, you'll not only have had a good review of basic Mendelian genetics (and even a little bit of molecular genetics), you'll be familiar with a bunch of new and fairly abstract genetic concepts. Just what you were looking for, right?
2. Population genetics involves a fair amount of mathematics, probability theory, and statistics.² That's because we deal with genetic variation in populations, which is measured in terms of gene and genotype frequencies. The phenomena of Mendelian genetics are themselves inherently statistical. So it shouldn't be surprising that when we apply these principles to a whole population the problems become even more mathematically involved.

That's the bad news. The good news is that the math we need is (mostly) quite simple, some basic algebra and probability theory. When we need things that are more advanced, I'll explain them in class. The other good news is that I expect you to have lost any familiarity you once had with genetics, algebra, and probability, so we'll be doing almost everything from scratch. The last bit of good news is that I'll try to emphasize how to apply the basic principles of population genetics, not the math involved in deriving those principles.

I'll be placing particular emphasis on using different computer pacakages for for analysis and interpretation of data encountered in population genetics, and the problems and projects will involve using those packages. They will evaluate your ability to use the principles and methods of population genetics, not your ability to derive them.³

If for some reason you're interested in courses from earlier years, here are the links.⁴

• 1996

• 1999

• 2001

• 2004

  • Lecture schedule with links to individual lectures

  • Consolidated reading list

¹"One must learn by doing the thing; for though you think you know it, you have no certainty until you try." Sophocles ca. 450 B.C.E.

²You probably know that R. A. Fisher, Sewall Wright, and J. B. S. Haldane are the founding fathers of population genetics. You may not know that R. A. Fishers is often regarded as the father of modern statistics. Is it any wonder that there's a lot of math and statistics involved in population genetics?

³I lied. There's one more piece of good news. There are quite a few people around who have already survived this course. That means it is possible. It also means that there are quite a few copies of old problem sets and projects floating around, and that there are quite a few people who are already familiar with the intricacies of marginal fitness, additive effects, and Jukes-Cantor whom you can ask for advice and help (or at least there are a lot of people who have heard those words before).

⁴I can't guarantee that all the links work any more, but you might find something interesting.