is bounded below by (following Lemma 7.2). For a fraction Dt of a generation we can write
If M(t) is the size of the population at time t (allowing the overall population size to be variable for the time being), then
and
using the fact that the population as a whole increases at a rate determined by the observed average fitness . It follows that
where .
If we use a discrete time-scale t = 1, 2, 3, . . . then Dt = (t+ 1) - t = 1 and
If we take the limit as Dt ® 0, in effect going to a continuous time-scale, we have
The equation , when restricted to alleles (schemata defined on one position), is just Fisher's (1930) classical result, relating the change in proportion of an allele to its average excess. We see however that the equation holds for arbitrary schemata. This gives us a way of predicting the rate of increase of a set of alleles with epistatic interactions from a sample average of the fitnesses of chromosomes carrying the set of alleles.
is bounded below by 
(following Lemma 7.2). For a fraction Dt of a generation we can write
. It follows that
.
, when restricted to alleles (schemata defined on one position), is just Fisher's (1930) classical result, relating the change in proportion of an allele to its average excess. We see however that the equation holds for arbitrary schemata. This gives us a way of predicting the rate of increase of a set of alleles with epistatic interactions from a sample average 
of the fitnesses of chromosomes carrying the set of alleles.