   Here \(Q_i^{OE}\) are a range of possible offspring numbers in generation \(i\), \(P(Q_i^{OE})\) is the probabilistic propensity to leave \(Q_i^{OE}\) in generation \(i\), and most important \(f(E, \sigma^2)\) is “some function of the variance in offspring numbers for a given type, \(\sigma^2\), and of the pattern of variation” (1990, 20). Brandon means “some function or other, we know not what in advance of examining the case.” Moreover, we will have to add to variance other factors that determine the function, such as Beatty and Finsen’s skew, or the conditions which Ekbohm, Fagerstrom, and Agren identify as making higher variance adaptive, etc. Thus, the final term in Brandon’s definition will have to be expanded to \(f(E,\sigma^2,\ldots)\), where the ellipsis indicate the additional statistical factors which sometimes combine with or cancel the variance to determine fitness levels.