The maintenance of diversity

摘要

Environmental heterogeneity is an important factor in the maintenance of species diversity. Yet diversity also persists in some homogeneous environments. Ecological theory has struggled, in particular, to account for the diversity of metabolic strategies found in seemingly homogeneous populations of microbes grown in chemostats. A new explanation that fits the experimental data is now offered. At realistic mutation rates, there is a coexistence between fit genotypes that have unfit neighbours on the adaptive landscape, and less fit but more mutationally robust (or 'flat') genotypes.