The evolutionary origins of modularity
Jeff Clune1,2,†⇓, Jean-Baptiste Mouret3,† and Hod Lipson1
- Author Affiliations
1Cornell University, Ithaca, NY, USA
2University of Wyoming, Laramie, WY, USA
3ISIR, Université Pierre et Marie Curie-Paris 6, CNRS UMR 7222, Paris, France
↵† These authors contributed equally to this work.
A central biological question is how natural organisms are so evolvable (capable of quickly adapting to new environments). A key driver of evolvability is the widespread modularity of biological networks—their organization as functional, sparsely connected subunits—but there is no consensus regarding why modularity itself evolved. Although most hypotheses assume indirect selection for evolvability, here we demonstrate that the ubiquitous, direct selection pressure to reduce the cost of connections between network nodes causes the emergence of modular networks. Computational evolution experiments with selection pressures to maximize network performance and minimize connection costs yield networks that are significantly more modular and more evolvable than control experiments that only select for performance. These results will catalyse research in numerous disciplines, such as neuroscience and genetics, and enhance our ability to harness evolution for engineering purposes.
modularity evolution networks evolvability systems biology
Received November 30, 2012.
Accepted January 9, 2013.
© 2013 The Authors. Published by the Royal Society under the terms of the Creative Commons Attribution License
http://creativecommons.org/licenses/by/3.0/, which permits unrestricted use, provided the original author and source are credited.