Formalizing complexity in the life sciences: systems, emergence, and metafluxes

Current plant sciences (as the life sciences in general) tend to follow an empirical rationale focussing on the molecular scale (genes, proteins), which is supposed to causally dominate processes at higher levels of organization (cellular, organismic). This rather simplistic view on the complexity of living systems calls for a more adequate and elaborate theoretical approach, to which I want to contribute three main cornerstones here. Systems theory is the first one, mostly referring to Mario Bunge’s CESM (Composition, Environment, Structure, Mechanism) approach and its biological application. More than half of this article is dedicated to the philosophical concept of emergence, denoting the fact that systems have specific properties not shared or provided by their parts. Different viewpoints on emergence and definitions are contrasted and their potential suitability for the life sciences is discussed. An interesting historical case study is the genesis of the ‘ecosystem’ concept in plant ecology. Subsequently two widely accepted subtypes, ‘weak’ and ‘strong’ emergence are introduced and their quantitative formalization is briefly outlined referring to recent work on this issue. Finally, the metaflux concept is presented for the first time. Living systems are characterized by a network of coupled fluxes of matter, free energy, and entropy, adequately formalized by the thermodynamics of irreversible processes. Dynamical phenomena in organisms emerging from these flux networks which are, in contrast to process philosophy/metaphysics, defined on a scientific (physicochemical) basis will be called ‘metafluxes’. Metafluxes and weak and strong emergence are non-exclusive concepts to be employed in a dialectic scientific process.