Shaping Theoretic Foundations of Holobiont-Like Systems

Acknowledging the fact that organisms never evolve in isolation, Zilber-Rosenberg and Rosenberg emphasized the concept of the holobiont, comprising a host organism together with all of its associated microorganisms. Considering the holobiont as being a unit of selection, the hologenome theory of evolution then leads to incorporate Lamarckian aspects into the cycle of adaptation and selection. Nevertheless, the concept of the holobiont carries an implicit temporal dependency. Similar contingencies can be identified for other ideas, e.g., the notion of a supraorganism. Building on ideas from computational thermodynamics and information theory leads to the concept of a holobiont-like system. This notion aims at capturing the essentials of a system of interacting biological agents, being driven by an evolutionary algorithm. The concept can be applied upon several scales, allowing to consider the holobiont sensu stricto as well as full ecosystems. It nicely frames within the metaphor of the adaptive cycle and, thus, leads to deeper insights into sustainability of biological systems.