Genotype networks shed light on evolutionary constraints

Trends Ecol Evol. 2011 Nov;26(11):577-84. doi: 10.1016/j.tree.2011.07.001. Epub 2011 Aug 15.


An evolutionary constraint is a bias or limitation in phenotypic variation that a biological system produces. One can distinguish physicochemical, selective, genetic and developmental causes of such constraints. Here, I discuss these causes in three classes of system that bring forth many phenotypic traits and evolutionary innovations: regulatory circuits, macromolecules and metabolic networks. In these systems, genotypes with the same phenotype form large genotype networks that extend throughout a vast genotype space. Such genotype networks can help unify different causes of evolutionary constraints. They can show that these causes ultimately emerge from the process of development; that is, how phenotypes form from genotypes. Furthermore, they can explain important consequences of constraints, such as punctuated stasis and canalization.

Publication types

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

MeSH terms

  • Bacteria / genetics
  • Bacterial Physiological Phenomena*
  • Eukaryota / genetics
  • Eukaryota / physiology*
  • Evolution, Molecular*
  • Gene Regulatory Networks
  • Genetic Variation
  • Genotype*
  • Macromolecular Substances / metabolism
  • Metabolic Networks and Pathways
  • Phenotype


  • Macromolecular Substances