SANTA FE INSTITUTE, NICOLAS RIGHETTITraits that initially confer a selective advantage often later become beneficial in some unrelated—and often surprising—way. A classic example of a so-called pre-adaptive trait, or exaptation, is the feather, which originated for a purpose other than flight. Although numerous anecdotal examples of exaptations litter the evolutionary biology literature, it is unclear how commonplace they are. Research published today (July 14) on simulated metabolic networks, however, suggests that exaptations may in fact outnumber adaptations several-fold.
“The paper is an important effort to characterize the frequency of exaptation as an evolutionary mechanism,” Richard Blob, an evolutionary biologist at Clemson University who was not involved in the study, said in an email. “The authors have identified an effective system to begin approaching this question in a systematic way.”
Leading the research was Andreas Wagner, an evolutionary biologist at the University of Zurich, who studies evolutionary innovation across many levels of biological organization, from genes to organisms to communities. Publishing in Nature with coauthor Aditya Barve, Wagner described the ubiquity of exaptations in metabolism, one of the most critical—and ancient—systems common to all multicellular organisms. To address this question, Wagner created sophisticated simulations of thousands of metabolic networks, each with a set of ...
