Energy saving mechanisms, collective behavior and the variation range hypothesis in biological systems: A review

TL;DR

This review explores various energy saving mechanisms in biological systems, presenting a thermodynamic framework, and discusses the variation range hypothesis, which suggests evolutionary convergence of energy savings among group members.

Contribution

It introduces a comprehensive thermodynamic framework and reviews evidence supporting the variation range hypothesis in biological energy saving mechanisms.

Findings

Energy saving mechanisms are widespread across biological systems.

The variation range hypothesis is supported by empirical evidence.

Self-organized structures emerge due to energy saving mechanisms.

Abstract

Energy saving mechanisms are ubiquitous in nature. Aerodynamic and hydrodynamic drafting, vortice uplift, Bernoulli suction, thermoregulatory coupling, path following, physical hooks, synchronization, and cooperation are only some of the better-known examples. While drafting mechanisms also appear in non-biological systems such as sedimentation and particle vortices, the broad spectrum of these mechanisms appears more diversely in biological systems including bacteria, spermatozoa, various aquatic species, birds, land animals, semi-fluid dwellers like turtle hatchlings, as well as human systems. We present the thermodynamic framework for energy saving mechanisms, and we review evidence in favor of the variation range hypothesis. This hypothesis posits that, as an evolutionary process, the variation range between strongest and weakest group members converges on the equivalent energy saving quantity that is generated by the energy saving mechanism. We also review self-organized structures that emerge due to energy saving mechanisms, including convective processes that can be observed in many systems over both short and long time scales, as well as high collective output processes in which a form of collective position locking occurs.