Paper 2: Genetics and Evolution
Tutorial 7
Population Genetics
The Hardy-Weinberg Law is a satisfactory model for explaining why phenotypes do not
disappear through blending, and for predicting genotype and phenotype ratios from one
generation to the next. Write an essay to answer the following questions.
Essay Questions: Discuss examples of genetic variation found within human populations and
as part of this discussion, answer the following: What are the principles and assumptions of
Hardy-Weinberg Law? Explain why the H-W Law is not a satisfactory model for evolution
over large numbers of generations. What are the processes in the evolution of human
populations that have led to:
(a) the appearance of new variation (in genes and phenotypes),
(b) the loss of variation, and
(c) the long-term maintenance of polymorphism?
Recommended texts:
Hartwell, L.H., Hood, L., Goldberg, M.L., Reynolds, A.E., Silver L.M., and Veres R.C.,
(2004, 2000) Genetics, From Genes to Genomes. McGraw Hill, 2nd edition
Chapter 20: The genetic analysis of populations and how they evolve, p. 677-692.
Griffiths, A.J.F., Miller, J.H., Suzuki, D.T., Lewontin, R.C. and Gelbart, W.M. (2000) An
Introduction to Genetic Analysis. Freeman. Chapter 24: Population Genetics;
Chapter 26: Evolutionary Genetics.
Jobling M.A., Hurles M.E., and Tyler-Smith C. (2004) Human Evolutionary Genetics:
Origins, Peoples and Disease. Garland Publishing, New York.
Strachan, T. and Read, A. P. (2004) Human Molecular Genetics 3. Third edition, Garland
Science. Chapter 12.5 Evolution of human populations, p. 385-391
Articles from The Encyclopedia of Life Sciences http://www.els.net/.
Armour, J. A. L. (2001) Genetic Variation: Human. ELS
Clegg, J. (2001) Selection and Common Monogenic Disease. ELS
Harrison, R. M. (2001) Variation, within Species: Introduction. ELS
Other reading:
Crow, J. F. (2001) The beanbag lives on. Nature 409:771.
Diamond, J. M. and Rotter, J. J. (1987) Observing the founder effect in human evolution.
Nature 329:105-106
Diamond, J. M. (2003) The double puzzle of diabetes. Nature 423:599-602
Kreitman, M. and Di Rienzo A. (2004) Balancing claims for balancing selection. Trends in
Genetics 20(7):300-304.