Species selection maintains self-incompatibility

Science. 2010 Oct 22;330(6003):493-5. doi: 10.1126/science.1194513.


Identifying traits that affect rates of speciation and extinction and, hence, explain differences in species diversity among clades is a major goal of evolutionary biology. Detecting such traits is especially difficult when they undergo frequent transitions between states. Self-incompatibility, the ability of hermaphrodites to enforce outcrossing, is frequently lost in flowering plants, enabling self-fertilization. We show, however, that in the nightshade plant family (Solanaceae), species with functional self-incompatibility diversify at a significantly higher rate than those without it. The apparent short-term advantages of potentially self-fertilizing individuals are therefore offset by strong species selection, which favors obligate outcrossing.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Biological Evolution
  • Fertilization / physiology*
  • Genetic Speciation*
  • Genetic Variation
  • Inbreeding
  • Phylogeny
  • Selection, Genetic*
  • Solanaceae / classification
  • Solanaceae / genetics
  • Solanaceae / physiology*