Seeing double: appreciating genetic redundancy.

informational homeostasis, even when a member of the network is lost through gene mutation. This review presents the characteristics of redundant regulation through the use of several well-characterized examples from animals and plants. We present models of evolutionary selection that provide new explanations of the perdurance of genetic redundancies in populations and put forth experimental approaches that anticipate the common occurrence of genetic redundancy within gene pathways. The application of these experimental approaches should result in the identification of new genes whose functions might not be revealed in more conventional genetic and reverse genetic experiments.