Send to

Choose Destination
See comment in PubMed Commons below
Proc Natl Acad Sci U S A. 2002 Aug 6;99(16):10528-32. Epub 2002 Jun 24.

Waddington's canalization revisited: developmental stability and evolution.

Author information

  • 1Department of Biological Sciences, and Center for Computational Genetics and Biological Modeling, Stanford University, Stanford, CA 94305-5020, USA.


Most species maintain abundant genetic variation and experience a range of environmental conditions, yet phenotypic variation is low. That is, development is robust to changes in genotype and environment. It has been claimed that this robustness, termed canalization, evolves because of long-term natural selection for optimal phenotypes. We show that the developmental process, here modeled as a network of interacting transcriptional regulators, constrains the genetic system to produce canalization, even without selection toward an optimum. The extent of canalization, measured as the insensitivity to mutation of a network's equilibrium state, depends on the complexity of the network, such that more highly connected networks evolve to be more canalized. We argue that canalization may be an inevitable consequence of complex developmental-genetic processes and thus requires no explanation in terms of evolution to suppress phenotypic variation.

Comment in

[PubMed - indexed for MEDLINE]
Free PMC Article
PubMed Commons home

PubMed Commons

How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for HighWire Icon for PubMed Central
    Loading ...
    Support Center