The number of identical deleterious mutations present in a population
may become very large, depending on the combined effect of genetic dri
ft, population growth and limited negative selection. The distribution
of the length of the shared area between two random chromosomes carry
ing the mutations has been investigated for a number of generations va
rying from 20-100 since introduction. The consequences for investigati
ons using association and haplotype sharing methods are discussed. (C)
1997 Wiley-Liss, Inc.