title: The biological default state of cell proliferation with variation and motility, a fundamental principle for a theory of organisms.
abstract: The principle of inertia is central to the modern scientific revolution. By postulating this principle Galileo at once identified a pertinent physical observable (momentum) and a conservation law (momentum conservation). He then could scientifically analyze what modifies inertial movement: gravitation and friction. Inertia, the default state in mechanics, represented a major theoretical commitment: there is no need to explain uniform rectilinear motion, rather, there is a need to explain departures from it. By analogy, we propose a biological default state of proliferation with variation and motility. From this theoretical commitment, what requires explanation is proliferative quiescence, lack of variation, lack of movement. That proliferation is the default state is axiomatic for biologists studying unicellular organisms. Moreover, it is implied in Darwin's "descent with modification". Although a "default state" is a theoretical construct and a limit case that does not need to be instantiated, conditions that closely resemble unrestrained cell proliferation are readily obtained experimentally. We will illustrate theoretical and experimental consequences of applying and of ignoring this principle.
authors.affiliation: Centre Cavaillès, République des Savoirs, CNRS USR3608, Collège de France et Ecole Normale Supérieure, Paris, France; Department of Integrative Physiology and Pathobiology, Tufts University School of Medicine, Boston, MA, USA. Electronic address: ana.soto@tufts.edu.
authors.forename: Ana M
authors.initials: AM
authors.lastname: Soto
authors.affiliation: Centre Cavaillès, République des Savoirs, CNRS USR3608, Collège de France et Ecole Normale Supérieure, Paris, France; Department of Integrative Physiology and Pathobiology, Tufts University School of Medicine, Boston, MA, USA. Electronic address: Giuseppe.Longo@ens.fr.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Longo
authors.affiliation: Laboratoire "Matière et Systèmes Complexes" (MSC), UMR 7057 CNRS, Université Paris 7 Diderot, 75205, Paris Cedex 13, France; Institut d'Histoire et de Philosophie des Sciences et des Techniques (IHPST), UMR 8590, 13, rue du Four, 75006, Paris, France. Electronic address: mael.montevil@gmail.com.
authors.forename: Maël
authors.initials: M
authors.lastname: Montévil
authors.affiliation: Department of Integrative Physiology and Pathobiology, Tufts University School of Medicine, Boston, MA, USA; Centre Cavaillès, Ecole Normale Supérieure, Paris, France; Institut d'Etudes Avancées de Nantes, France. Electronic address: carlos.sonnenschein@tufts.edu.
authors.forename: Carlos
authors.initials: C
authors.lastname: Sonnenschein
mesh_terms: D000818:Animals; D005075:Biological Evolution; D064229:Biological Ontologies; D001695:Biology / Q000379:methods*; D002465:Cell Movement; D049109:Cell Proliferation; D006801:Humans; D010802:Phylogeny
keywords: Biological organization; Default state; Emergence; Mathematical symmetries; Organicism; Theory