Seminar Notice
                Statistical Laboratory
                 Iowa State University

DATE AND TIME:     Monday, October 6, 1997, 4:10 p.m.

PLACE:             319 Snedecor Hall

SPEAKER:           Edward Pollak
                   Department of Statistics
                   Iowa State University
                   
TITLE:             The Effective Size of a Partially Selfing Age-
                   Structured Population     

                       ABSTRACT

    Consider a large population, with the same age distribution at times 0, 1,
2, ..., in which there is reproduction by selfing with probability beta and by
random mating with probability 1 minus beta.  An individual between i and i + 1
units of age at time t is said to be in age group i at that time.  Let L be the
mean, among copies of an allele A in genotypes of offspring of age group 0,
of ages of parents when the inbreeding coefficient has attained an equilibrium
value.  Then if there is no selection and allele A is originally present in one
heterozygote, the probability that it is ultimately fixed is 1/(2N_0L), where 
N_0 is the number of individuals in age group 0 at any time.  The effective
population size an then be derived.  It turns out to be the same as for a
population with discrete generations having the same mean and variance of the
number of successful gametes produced during a lifetime and the same number
of individuals entering the population per generation.

COFFEE: 3:45 p.m., 104 Snedecor Hall