Soft Modes as a Predictive Framework for Low Dimensional Biological Systems across Scales

TL;DR

This paper proposes a unifying dynamical systems framework based on soft modes to explain the low-dimensional responses of biological systems across scales, from molecules to ecosystems, and makes testable predictions.

Contribution

It introduces soft modes as a general framework for understanding biological responses, extending classic ideas to diverse systems and predicting phenomena like phenocopying and global epistasis.

Findings

Soft modes explain low-dimensional biological responses.

Predictions include phenocopying, dual buffering, and global epistasis.

Framework applicable from protein biophysics to ecology.

Abstract

All biological systems are subject to perturbations: due to thermal fluctuations, external environments, or mutations. Yet, while biological systems are composed of thousands of interacting components, recent high-throughput experiments show that their response to perturbations is surprisingly low-dimensional: confined to only a few stereotyped changes out of the many possible. Here, we explore a unifying dynamical systems framework - soft modes - to explain and analyze low-dimensionality in biology, from molecules to eco-systems. We argue that this one framework of soft modes makes non-trivial predictions that generalize classic ideas from developmental biology to disparate systems, namely: phenocopying, dual buffering, and global epistasis. While some of these predictions have been borne out in experiments, we discuss how soft modes allow for a surprisingly far-reaching and unifying framework in which to analyze data from protein biophysics to microbial ecology.