Biology & Philosophy

, 34:52 | Cite as

On mycorrhizal individuality

  • Daniel J. MolterEmail author


This paper argues that a plant together with the symbiotic fungus attached to its roots, a mycorrhizal collective, is an evolutionary individual, and further, that mycorrhizal individuality has important implications for evolutionary theory. Theoretical individuation is defended and then employed to show that mycorrhizal collectives function as interactors according to David Hull’s replicatorinteractor model of evolution by natural selection, and because they have the potential to engage in pseudo-vertical transmission, mycorrhizal collectives also function as Darwinian individuals, according to Peter Godfrey-Smith’s Darwinian Populations model of evolution by natural selection. Mycorrhizae in nature usually connect the roots of multiple plants, so mycorrhizal individuality entails the existence of overlapping evolutionary individuals, and because the potential to engage in pseudo-vertical transmission comes in degrees, it follows that these overlapping evolutionary individuals also come in degrees. I suggest here that the degree of evolutionary individuality in a symbiotic collective corresponds to its probability of reproducing with vertical or pseudo-vertical transmission. This probability constitutes a fourth parameter of graded Darwinian individuality in collective reproducers and warrants an update to Godfrey-Smith’s 3D model.


Mycorrhizal symbiosis Evolutionary individuality Pseudo-vertical transmission Darwinian individual Replicator–interactor Great cube of being 



Thanks to Matt Haber, Melinda Fagan, Thomas Pradeu, Steve Downes, Anne Peterson, Derek Skillings, Jacob Stegenga, Peter Godfrey-Smith, and the Works in Progress Group at the University of Utah, especially Richard Figueroa and Eleanor Gilmore-Szott.

Compliance with ethical standards

Conflict of interest

The author declares he has no conflict of interest.


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© Springer Nature B.V. 2019

Authors and Affiliations

  1. 1.Department of Political Science and PhilosophyWeber State UniversityOgdenUSA

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