Article,
The effects of linkage and density-dependent regulation on gene flow
Heredity, 57 (3): 415--426 (December 1986)
Abstract
The rate of gene flow across a hybrid zone may be reduced by the presence of a physical barrier, by a reduction of
population density caused by reduced fitness of hybrids (the "hybrid sink" effect), and by linkage. If the reduction in
hybrid fitness is not extreme, the strength of the barrier to gene flow caused by these effects is_B =
Here, w is the width of the dine; p is the carrying capacity; W! is the mean fitness of
the population, excluding effects of density; R is the strength of density-dependent regulation; and i is the harmonic
mean recombination rate between the locus whose flow is .being calculated, and loci under selection. +, 0 denote
populations outside the hybrid zone, and at its centre, respectively. This relation is illustrated using data from hybrid
zones in Bombina and Podisma, and its implications for interpretation of data from nature are discussed.
