Significant deviations from linearity in the relationship between quantitative fitness traits and Wright's inbreeding coefficient
can indicate selection against deleterious alleles or the presence of epistatic gene action (Dobzhansky 1970; Falconer 1981).
If increases in the level of inbreeding, as measured by Wright's inbreeding coefficient
f, exceed 1% per generation, then a population is at risk for serious inbreeding depression.
Hence, most of the complexity in the previous models of changes in epistatic variance is unnecessary for most cases; we need consider only Wright's inbreeding coefficient
to understand most of the change of epistatic variance to additive variance.
The genotypic composition of each of 11 yr cohorts (1974-1984) was further characterized using Wright's inbreeding coefficient
(F; Wright 1951).
I was disappointed that Sewall Wright's inbreeding coefficients
, or F-statistics, were not given broader treatment in the theoretical chapters.