The Role of Coevolution

摘要

One of the great metaphors of evolutionary biology, introduced by Sewall Wright (7), is that populations evolve toward adaptive peaks separated by adaptive valleys. The peaks are combinations of genes that confer high Darwinian fitness on individuals, whereas the valleys are combinations that confer low fitness (see the figure). But how can a population move from one peak to another, perhaps higher, peak, across an adaptive valley in which gene combinations are presumed to be maladaptive? On page 428 of this issue, Meyer et al. (2) show that coevolution may favor key innovations that guide a population quickly onto the slope of a different adaptive peak.