Dimensional reduction and adaptation-development-evolution relation in evolved biological systems

TL;DR

This paper develops a universal theory linking biological robustness, dimensional reduction, and adaptive evolution across hierarchical systems, from molecules to multicellular organisms, highlighting constraints and proportionalities in biological change.

Contribution

It introduces a novel framework for understanding how high-dimensional biological states evolve through low-dimensional constraints, unifying cellular and multicellular development and evolution.

Findings

Adaptive changes are constrained to low-dimensional space.

Proportionality between evolutionary and environmental responses.

Dimensional reduction may collapse under nutrient limitation.

Abstract

Life systems are complex and hierarchical, with diverse components at different scales, yet they sustain themselves, grow, and evolve over time. How can a theory of such complex biological states be developed? Here we note that for a hierarchical biological system to be robust, it must achieve consistency between micro-scale (e.g. molecular) and macro-scale (e.g. cellular) phenomena. This allows for a universal theory of adaptive change in cells based on biological robustness and consistency between cellular growth and molecular replication. Here, we show how adaptive changes in high-dimensional phenotypes (biological states) are constrained to low-dimensional space, leading to the derivation of a macroscopic law for cellular states. The theory is then extended to evolution, leading to proportionality between evolutionary and environmental responses, as well as proportionality between phenotypic variances due to noise and due to genetic changes. The universality of the results across several models and experiments is demonstrated. Then, by further extending the theory of evolutionary dimensional reduction to multicellular systems, the relationship between multicellular development and evolution, in particular the developmental hourglass, is demonstrated. Finally, the possibility of collapse of dimensional reduction under nutrient limitation is discussed.