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Colloque: Biodiversity resilience

Cover slide from the talk “Colloque: Biodiversity resilience”

La relation entre biodiversité, variabilité, adaptabilité et résilience des systèmes vivants, soumis aux perturbations imprédictibles caractéristiques des systèmes complexes, quelles que soient leurs échelles, doit être questionnée, même en l’absence de mécanismes causalistes identifiables. La rencontre interdisciplinaires entre biologistes, immunologistes, écologues, philosophes, mathématiciens, physiciens, informaticiens permettra l’étude des concepts de diversité et de variabilité dans le vivant adaptatif et de leurs rôles dans la résilience des systèmes vivants multi-échelles et organisés.
Le système immunitaire adaptatif en cognition de l’environnement moléculaire des êtres vivants a co-évolué pour permettre la tolérance ou destruction de tissus et du microbiote et présente une biodiversité cellulaire et moléculaire exceptionnelle. Ces systèmes représentent des modèles d’étude de l’organisation et variation de systèmes dynamiques multi-échelles tout comme les écosystèmes macroscopiques. Il s’agira donc à travers les échelles des systèmes étudiés d’établir les modalités de synergie entre biodiversité et résilience ou robustesse.

Colloque Biodiversity Resilience

Approches théoriques et modélisation de la diversité biologique et résilience dynamique des systèmes complexes organisés multi-échelles : du système immunitaire aux macro-écosystèmes

Living and diversified organisms integrate macroscopic whole communities and ecosystems (biosphere, eco-systems, social and cultural networks) as well as microscopic complex systems from polygenomic origins (cells, lineages, receptors, molecules, microbes…). Following organisation principles, complex systems are always multi-scale, self-assembling, adaptive dynamic and cognitive networks of diverse interacting structures with inter-relationships in time and space through processes and cascades of events, capable of sensing patterns with degenerative properties and memory. These multi-scale spatio-temporal networks are organized, dynamical, variable and highly diversified systems and sub-systems, reacting to perturbations and thus evolving through unpredictable possible choices, adaptations and selection. We are confronted to alarming signals from ecological crises on various scales, such as climate change, pollution, chemicals, biotechnologies, diseases. Various levels of the living are affected which is exemplified by the alteration of species biodiversity but also of food, increase in inflammatory, auto-immune allergies and cancer diseases related to immune systems and microbiote dysfunction. It is time to question the origin, function and evolution of biodiversity at various scales in the behaviour of systems and their resilience.

The relationship between biodiversity, variability and resilience of living systems, submitted to unpredictable perturbations of complex systems, should be questioned independently of the scale of the systems, even if causals mechanisms could not be identified. The resilience and robustness of complex systems to perturbations is related to the historicity and dynamics of evolutionary systems. This questions the role of diversity and aging in resilience processes after perturbations of complex systems, where reductionist and linear causal approaches are insufficient. Interdisciplinary interactions and discussions between researchers involved in biology, ecology, evolutionary ecology, immune system, philosopher, mathematicians, physicists and computer scientists should help to structure thoughts and deepen reflexions on the co-evolution of the diversity in biology from ecosystems, species, to immune systems, through the notions of biological organization, evolutionary and ontogenetic historicity, aging, and resilience from microscopic to macroscopic levels.

Multi-scale living systems evolve and age in a context of finitude, heterogeneity and variation, leading to indecidability and incompleteness. The aim of the colloquium is to trigger a multidisciplinary reflexion on the organisation, evolution, variation of living systems and the potential role of diversity on resilience after perturbations and aging. The level of organisms that are cognitive organisation where measurements are currently done could help in this reflexion. In each organism, while the nervous system insures the cognition and perception of “self” and external environment at macroscopic scales, defining ego and consciousness, the adaptive immune system is a cognitive, dynamic and anamnestic system, sensing the quality and quantity of microscopic patterns. This “immunoception” perceives antigenic diversity and allows defining the temporal identity of the organism within micro/macroscopic environment that is permanently changing. In metazoan organisms the cognitive immune system presents an exceptional diversity at the level of cells and molecules and represent a prototype model of diversity. In particular in Gnathostomes the somatic diversified immuno-receptor repertoires of B and T lymphocytes constitute an adaptive evolving memory system in direct cognition with the diversity of antigens, microbes and molecules derived from food, issued from plants and animal co-evolution and where dynamic tolerance should be maintained to insure the life of every organism.

In the first part philosophical notions and the meaning of terms “biodiversity” and “resilience” their relation to dualism, categories, “être question” and historicity will be discussed in relation to variation and diversity in evolving living systems, leading to the notions of organisation and their characteristics.

In the second part, the effects of perturbations, aging of systems, disorganization and their resilience will be discussed in particular in relation to biodiversity. Examples in various micro-to macro domain from physics, ecology to microbiotes and immune systems will be used to guide the discussion.

This colloquium should allow the emergence of new interdisciplinary collaborations and reflexions between biologists, ecologists, immunologists, physicians, physicists, mathematicians and philosopher that are rarely in contact. Analysing the consequences of perturbations and the resilience (or not) of our multi-scale complex environment is an urgent reflexion scientist should have together.