This book explores the main biological dimensions underlying functional integration and examines how they contribute to defining a biological individual as both a physiological and evolutionary unit. Functional integration lies at the heart of most definitions of both organisms and biological individuals, making it explanatorily relevant to biology as well as to the philosophy of biology. However, the notion-typically referring to any causal interdependence among biological functions-remains broad and lacks a coherent theoretical framework. This work addresses that gap by focusing on functional integration at the cellular level, which presents both a minimal degree of complexity (relative to multicellular organisms) and maximal conceptual significance for this inquiry. By analysing the transition from prokaryotes to eukaryotes, the book sheds light on how spatial constraints, system-level regulatory mechanisms, spatio-temporal coordination, and system-level reproduction contribute to characterizing biological organization as a functionally integrated physiological unit. This study opens the way for a fresh reflection on the foundations of biological individuality, offering insights not only for researchers, but also for students and non-specialist readers.

Autorentext

Guglielmo Militello is currently a postdoctoral researcher at the University of Bordeaux and an affiliated member of the Institut d'Histoire et de Philosophie des Sciences et des Techniques (IHPST) in Paris and of the University Campus Biomedico in Rome. He holds a PhD in philosophy of biology from the University of the Basque Country, where he completed a dissertation on functional integration and biological individuality, with a particular focus on the prokaryote-to-eukaryote transition. His research lies at the intersection of philosophy of biology and philosophy of medicine, with a particular interest in the conceptual foundations of biological individuality, the theory of major evolutionary transitions, and the ontological and ethical implications of contemporary cancer research. He has worked on topics such as anticancer immunotherapies, (cancer) stem cells, and the biological conditions enabling tumorigenesis.