Population Genetics

Ecology and Evolutionary Biology 348

Spring, 2001

• Course Description
• Selected references
• Tentative lecture schedule
• Other sites of interest on the web
• Simple population genetic simulations (as Java applets for online viewing)
• Links to software used in the course
• The 1996 edition of this course
• The 1999 edition of this course

The large projects will involve reading of the primary literature and analysis of some associated data. You will be asked to write 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 projects, I will make periodic homework assignments. These aren't to be handed in or graded, but they will have questions on them similar to those you will encounter in the projects. Working throught them will be good practice in applying the concepts you'll need to know well for your projects. ("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.)

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 we can see easily, like phenotypic variation, we intoduce abstract concepts, like additive genetic variance, 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 genetic concepts. Just what you were looking for, right?
2. Population genetics involves a fair amount of mathematics. 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 simplesome 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, so we'll be doing all the genetics 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. We will be making especially heavy use of computers and statistical methods for analysis of data encountered in population genetics. So if you haven't had a statistics course before (or even if you have), you're going to be learning some statistical principles that you're likely to find useful in many other applications. The problems and projects will, however, evaluate your ability to use the principles and methods, not your ability to derive them. (I 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 exams, 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. On the other hand, the format of this course is quite different from when any previous students took it, so they won't be able to help you with WinBUGS or QTL mapping.

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