The making of a social insect: developmental architectures of social design

Authors

  • Robert E. Page Jr.,

    Corresponding author
    1. Arizona State University, School of Life Sciences, Tempe AZ
    • Arizona State University, School of Life Sciences, P.O. Box 854501, Tempe AZ 85287-4501.
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  • Gro V. Amdam

    1. Arizona State University, School of Life Sciences, Tempe AZ
    2. Norwegian University of Life Sciences, Department of Animal and Aquacultural Sciences, Aas, Norway
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Abstract

We marvel at the social complexity of insects, marked by anatomically and behaviorally distinguishable castes, division of labor and specialization—but how do such systems evolve? Insect societies are composed of individuals, each undergoing its own developmental process and each containing its own genetic information and experiencing its own developmental and experiential environment. Yet societies appear to function as if the colonies themselves are individuals with novel “social genes” and novel social developmental processes. We propose an alternative hypothesis. The origins of complex social behavior, from which insect societies emerge, are derived from ancestral developmental programs. These programs originated in ancient solitary insects and required little evolutionary remodeling. We present evidence from behavioral assays, selective breeding, genetic mapping, functional genomics and endocrinology, and comparative anatomy and physiology. These insights explain how complex social behavior can evolve from heterochronic changes in reproductive signaling systems that govern ubiquitous and ancient relationships between behavior and ovarian development. BioEssays 29:334–343, 2007. © 2007 Wiley Periodicals, Inc.

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