Evolution and Population Genetics Seminar
Genetics 590
Autumn, 2001
The Evolution and Population Genetics seminar will meet on Tuesdays in
Autumn quarter in
Health Sciences Building J182
from 12:30pm - 1:20pm. This quarter the
topic will be
Advanced Topics in Theoretical Evolutionary Genetics
The intention is to treat a number of topics in theoretical evolutionary
genetics (theoretical population genetics) by reading papers from the
literature and discussing them. Students in the course will be expected to
lead one of these sessions, to do all readings, and to participate actively.
Some of the topics which are likely to be covered are:
- Two-locus selection theory
- Justification of the diffusion approximation for gene frequencies
- Models for maintenance of variation in polygenic traits
- Stepping-stone models of geographic variation
- Mathematics of clines
Participants will read papers in this area
and will be expected to lead discussion once during the quarter.
Readings will be listed below.
The weekly references will be available to be copied in the copy room of the Genetics Department,
J205 Health Sciences Building, and they are to be listed below.
The course will presuppose knowledge of elementary theoretical
population genetics. It is a graduate course with prerequisite Genetics 562 or
permission of the instructor.
Joe Felsenstein (joe@genetics.washington.edu)
Readings for coming sessions
Some of these are available on-line in electronic journals subscribed to
by the University. The links here will lead to them. For those papers
we will not make paper copies available: students should print their own.
October 2
Organizational meeting. At which peoples' attention will directed to the
material below:
October 9
Two-locus theory: founding papers
- Kimura, M. 1956. A model of a genetic system which leads to closer
linkage by natural selection. Evolution 10: 278-287.
(Available
in JSTOR)
- Lewontin, R. C. and K. Kojima. 1960. The evolutionary dynamics of complex
polymorphisms. Evolution 14: 458-472.
(Available
in JSTOR)
Question to look into: are the equations in each of these papers exact or
approximate for the models described?
October 16
Two-locus theory: further development
- Lewontin, R. C. 1964. The interaction of selection and linkage. I.
General considerations; heterotic models. Genetics 49: 49-67.
- Karlin, S., and M. W. Feldman. 1970. Linkage and selection: new
equilibrium properties of the two-locus symmetric viability model.
Proceedings of the National Academy of Sciences USA 62: 70-74.
(Available in JSTOR)
(the Lewontin paper is not available on-line). Questions: what generalizations were people trying to make? Did
they succeed in finding them?
October 23
Diffusion approximations: why they work
- Feller, W. 1951. Diffusion equations in genetics. Proceedings
of the Second Berkeley Symposium on Mathematical Statistics and Probability, ed. J. Neyman. University of California Press, Berkeley.
- Karlin, S., and J. McGregor. 1964. On some stochastic models in
genetics. pp. 245-279 in Stochastic Models in Medicine and Biology,
ed. J. Gurland. University of Wisconsin Press, Madison.
(Neither of these is available on-line).
Question: Does the method of asymptotically approaching the diffusion
process give us a justification for it in cases where we are not at the
asymptote?
October 30
Diffusion approximations: why they work (continued) (Presenter: Oliver Will)
(same references)
November 6
Variability in quantitative characters in natural populations (Presenter: Amy Anderson)
- Bulmer, M. 1971. The effect of selection on genetic variability.
American Naturalist 105: 201-211.
(Available in JSTOR)
- Lande, R. 1975. The maintenance of genetic variability by mutation in a polygenic character with linked loci. Genetical Research 26: 221-235. (Not available on-line)
If you can get ahold of a copy of a recent edition (in the last few years) of
my notes "Theoretical Evolutionary Genetics" for Genetics 562, and can read
chapter XI, that will help with these papers.
Questions: Bulmer assumes (what?) part of the variance doesn't disappear
under selection. What does this mean he is in effect assuming about number
of loci, gene effects? Lande assumes that the distributions of gene effects
remain normal. What does that assume about the strength of selection,
and about mutation?
November 13
Variability in quantitative characters in natural populations, part II
(presenter: Peter Beerli)
Barton, N. H. and M. Turelli . 1989. Evolutionary quantitative genetics: how
little do we know? Annual Review of Genetics 23: 337-370.
(not available on-line)
November 20
Stepping-stone and continuum models with drift and mutation (presenter: Sacha Vignieri)
- Kimura, M., and G. H. Weiss. 1964. The stepping stone model of population
structure and the decrease of genetic correlation with distance.
Genetics 49: 561-576. (not available on line)
- Malécot, G. 1969. The Mathematics of Heredity. W. H. Freeman,
San Francisco. (translation by D. M. Yermanos of Les Mathématiques
de l' Hérédité, Masson, Paris, 1948) (we will read sections 3.3 and 3.4) (not available on line)
- Felsenstein, J. 1975. A pain in the torus: some difficulties with models
of isolation by distance. American Naturalist 109: 359-368.
(Available in JSTOR)
November 27
More on stepping-stone models: patch swamping and such (presenter: Chris Hess)
- Kimura, M., and T. Maruyama. 1971. Pattern of neutral polymorphism in a
geographically structured population. Genetical Research 18:
125-131.
- Hanson, W. D. 1966. Effects of partial isolation (distance), migration,
and different fitness
requirements among environmental pockets upon steady state gene frequencies.
Biometrics 22: 453-468.
These papers are not available on-line.
Kimura and Maruyama: how much gene flow is needed to prevent local differentiation by genetic drift in different kinds of geographic structures?
Hanson: (This paper actually should have been put in the clines section, after
the founding papers. Oops.) Under what circumstances can a patch of
local adaptation by selection be eliminated by gene flow?
December 4
Clines: founding papers (presenter: Josh Whorley)
- Haldane, J. B. S. 1948. The theory of a cline. Journal of
Genetics 48: 277-284.
- Fisher, R. A. 1950. Gene frequencies in a cline determined by selection
and diffusion. Biometrics 6: 353-361.
- Wilkes, M. V. 1975. How Babbage's dream came true. Nature
257: 541-544.
(In addition to thinking about clines, look in Wilkes's article for the mention of the Fisher paper. Are there any
earlier examples of use of computers in biology?)
December 11
Clines: linkage and underdominance (presenter: Solly Sieberts)
- Bazykin, A. D. 1969. Hypothetical mechanism of speciation.
Evolution 23: 685-687.
(Available in JSTOR)
- Slatkin, M. 1975. Gene flow and selection in a two-locus system
Genetics 81: 787-802. (Not available on-line).
How do different loci, each of which show geographic differentiation,
arrange themselves in clines? Do they affect each other's pattern of
geographic differentiation? Does this have any relevance to speciation?