Evolution evolving? Reflections on big questions

Abstract

John Bonner managed a long and productive career that balanced specialized inquiry into cellular slime molds with general investigations of big questions in evolutionary biology, such as the origins of multicellular development and the evolution of complexity. This commentary engages with his final paper (“The evolution of evolution”), which argues that the evolutionary process has changed through the history of life. In particular, Bonner emphasizes the possibility that natural selection plays different roles at different size scales. I identify some underlying assumptions in his argument and evaluate its cogency to both foster future discussion and emulate the intellectual example set by Bonner over a lifetime. This endeavor is important beyond Bonner's own theoretical disposition because similar issues are visible in controversies about the possibility of an extended evolutionary synthesis.

Metabolic and microbial perspectives on the “evolution of evolution”

“…Bonner suggests unicellular organisms tend to "just exist side-by-side, totally ignoring one another." We think this claim gives the wrong impression of the ecological and evolutionary processes that characterize the microbial world (see Love, 2019, for a similar interpretation). In the first place, no theorist would suggest that evolution by natural selection was not occurring before the Phanerozoic.…”

“…The inclusion of human culture, which is commonplace among major transition theories, exacerbates problems of progressivism and disunity (see O'Malley & Powell, ); however, we will leave cultural evolution aside in this essay to focus on the more novel idea of noncompetitive unicellular evolution. Bonner suggests unicellular organisms tend to “just exist side‐by‐side, totally ignoring one another.” We think this claim gives the wrong impression of the ecological and evolutionary processes that characterize the microbial world (see Love, , for a similar interpretation). In the first place, no theorist would suggest that evolution by natural selection was not occurring before the Phanerozoic.…”