International Society for History, Philosophy, and Social Studies of Biology

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MONDAY, JULY 6  /  09:00 - 10:30  /  DS-M220
Organized session / standard talks
Boundaries and levels of biological organization (1)

Jon Umerez (University of the Basque Country, Spain)

This double session will discuss the notion of biological organization from a system-theoretical perspective. In particular it will focus on its intrinsic hierarchical dimension, and on the role organization plays in the understanding of the transition from pre-biotic to minimal living systems and of the evolution towards more complex forms of biological, cognitive and ecological systems. More specifically, it will also address issues regarding individuality and autonomy at cellular and multicellular levels, from developmental and ecological perspectives as well as from genetic and evolutionary ones. Formation of boundaries at prebiotic scenarios and complex interactions at individual versus environment interfaces are also dealt with. The conceptual framework involves clarification of such general concepts as those of organization or level in terms of constraints, the characterization of regulation at its minimal instances or the assessment of diverse attempts to naturalize teleology. The double session is divided into two parts: a more general and conceptual one first, followed by another more specific and field centered.

From levels of organization to the organization of levels

Mael Montévil (Université Paris Diderot - Paris 7, France); Matteo Mossio (IHPST/ Université Paris 1 Panthéon-Sorbonne, France)

We propose a theoretical and formal way to account for the various levels of organization that biological systems may realize. Our key assumption is that levels of organization are to be understood as specific networks of interdependences among the functional constituents. More precisely, we will rely on the notion of organizational closure, which refers to the mutual construction and stabilization of constituents playing the role of constraints within the system. A level of biological organization, we will argue, is a level of closure of constraints. With this characterization in hand, we will first discuss those situations in which different levels of organization can be distinguished, and hierarchically articulated, by relying on sharp discontinuities. In particular, this is the case of cells within multicellular organisms. We will then focus on those more complex cases in which the description of a level of organization requires appealing to the notion of “tendency to closure”, which aims to deal with the qualitative notion of level of organization by quantitative means. In particular, the tendency to closure involves a quantitative measure of functional interdependences at the relevant spatial scale at which constraints operate. We conclude with a preliminary discussion of the spatiotemporal conditions (in particular: the dependence on large space scale and small time scale) that enable the coherence of organisms realizing high levels of organization (e.g. mammals).

Regulation in biological systems

Leonardo Bich (Instituto de Filosofia y Ciencias de la Complejidad, Chile); Alvaro Moreno (University of the Basque Country, Spain)

The appeal to the notion of regulation is widespread in biology. This property is usually ascribed to a variety of mechanisms and behaviours involved in living systems’ responses to perturbations. Yet, the meaning of this notion is left somehow vague, very dissimilar types of phenomena are gathered under this label, and its relationship with akin concepts, such as control, homeostasis, robustness, and feedback is hardly stated in clear terms To contribute to a deeper understanding of this notion, we will propose an organisational account of regulation by focusing on the mechanisms underlying compensations for perturbations in minimal living systems. In the first place, we will analyse different forms of control in the cell, and how they contribute to the maintenance of a biological organization. In the second place we will analyse how basic biological organisation can recruit forms of control to viably compensate to internal or external perturbations. It does so in two main ways: through holistic responses as networks or by means of the action of specific subsystems dedicated to handle perturbations. On this basis we will distinguish between two different classes of responses, respectively: dynamical stability and regulation. we will describe the limits of stability as an adaptive response, and we will provide a definition and a minimal set of organizational requirement for regulation, by pointing out the differences with similar concepts such as feedback, robustness and homeostasis. Finally, we will discuss the importance of the invention of regulation for the evolution in complexity in biological systems.

Developmental and ecological processes of multicellular organization

Arantza Etxeberria (University of the Basque Country, Spain)

Philosophy of biology is exploring different ways of being an individual organism. At the cellular level, free living single cells are viewed as autonomous individuals, whereas those in a multicellular organism appear to be just parts of it. The extent to which microbes and multicellular entities can be compared as organismal entities is challenged by the role of microbes in multicellular organisms. According to models such as Buss’s, individual cells give up their autonomy and independence, which is subdued by a larger organization for which cells lineages divide and differentiate following developmental processes and rules. Recent evidences of the role of the microbiota in multicellular organization suggest that processes beyond genealogical lineages, plausibly of an ecological character, play a constitutive role. Yet, how do multispecies cells populating the organism acquire their roles in the multicellular whole? How are relations among microbial components constrained by the multicellular organization? How do rules of development (division and differentiation) and ecological/economical rules governing the interactions (symbiosis, etc.) integrate? In sum, an important issue of multicellular individuality is how biological levels of cellular organization are conceived. This paper considers that levels of multicellular organization can be explored both in terms of developmental and of ecological interactions among cells, with conflicting consequences about the individuality of multicellulars, as at least two levels of organization and interactions appear to coexist, one regulated by the upper level of organization and developmental rules and a second one regulated different evolutionary and ecological rules, and in which the boundaries of the individual organism will appear blurred. In what concerns multicellular autonomy, this view is coherent with the perspective that autonomy is not a fact of the living condition but a norm being pursued under contingent conditions of life.