Are Physiological Individuals Evolutionary Individuals? The Case of the Holobiont

Abstract In this article, I present the immunological account of physiological individuality courtesy of Thomas Pradeu and the evolutionary account of biological individuality from Ellen Clarke. I argue that in combination, the logic of these two accounts implies that all physiological individuals are capable of undergoing evolution by natural selection. The main objection to this view is the case of holobionts. Here I argue that this objection is unjustified and that holobionts meet basic criteria for evolutionary individuality. As such, this supports the view that physiological individuals are also evolutionary individuals.