We discussed Tajima’s D in class last week. As you’ll notice when you read this week’s exercise, I realized that I’ve been describing a couple of details concerning Tajima’s D incorrectly for several years. I’ve corrected the online notes, and you’ll find a brief reference to the differences in this week’s exercise. Fortunately, the details I got wrong don’t affect the interpretation of any results, only the way in which Tajima’s D is calculated. As usual, you can also find the exercise linked from the Lab Schedule page.

In grading Lab 7, the one on exploring the coalescent, I realized that the 1-dimensional stepping stone and the finite island model didn’t have quite the properties I expected when the number of populations is low. I verified the pattern many of you found, and the results are displayed here. You can also find a link to the results from the Lab Schedule page. We’ll talk more about what they mean and what they tell us about drift and migration on Tuesday.