Pick two allele frequencies, one for the A locus and one for the B locus. This defines a "population" (obviously this would be done in many dimensions for all loci in the genome; only two here for illustration). The population will evolve by selection to the top of the nearest peak. If a population starts with f(A) ~ f(B) ~ 0.2, this population would evolve to the top of the peak at the lower right of the diagram. This is not the highest peak, but selection acts to increase average fitness and can only "see" the nearest peak. If drift due to low effective population size rapidly shifted both f(A) and f(B) to higher frequencies, then the population might be in the "domain of attraction" of the highest peak in the upper right corner. The population would stop evolving when it reached the top of the highest peak because there is no higher peak to shift to unless the environment changes at which point we would have to redraw the adaptive landscape. Sewell Wright conceived of this view of evolution and believed that this was a more
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