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Genetic Drift Exercise


readings - introduction - exercise instructions - homework - instructor hints


Haldane, J.B.S. 1964. A defense of beanbag genetics. Perspectives in Biology and Medicine 7: 343-359.

Mayr, E. 1959. Where Are We? Cold Spring Harbor Symp. Quant. Biol . 24. pp1-14.

Introduction for students

This exercise illustrates the phenomenon of sampling error, which is the mechanism whereby genetic drift changes allele frequencies in populations. In this example a haploid model is used for simplicity. This exercise is designed to accompany an in-class discussion of genetic drift. 

Exercise Instructions


Instructor hints

2 bags of beans (one speckled and one white - cranberry and great northern are roughly the same size and shape)
Opaque containers to serve as source pools for selection of beans.