Redundancies, development and the flow of information.

There is increasing evidence for the wide-spread existence of functionally redundant genetic pathways in developmental processes. However, both their significance and manner of evolution are still matters of debate. I will argue here that redundancy of gene actions may, in fact, be a necessary requirement for the development and evolution of complex life forms. One can view development as a process that transmits information from the egg to the adult organism. Transmission of information is, however, always an error-prone process, which can only be safeguarded by including redundancies in the message. Molecular examples for well analysed redundant processes indicate that redundancies may best be understood within a conceptual framework of overlaps between different gene functions.