The Hiatus Between Organism and Machine Evolution: Contrasting Mixed Microbial Communities with Robots

TL;DR

This paper compares natural microbial community evolution driven by affordances with artificial robot evolution, highlighting the open-ended nature of natural evolution versus the limitations of algorithmic frameworks in artificial systems.

Contribution

It introduces a systemic perspective on microbial evolution, contrasting it with artificial evolution, and proposes an experimental setting to explore these differences.

Findings

Natural evolution extends possibilities in an open-ended manner.

Artificial evolution is limited by predefined algorithmic frameworks.

Microbial communities exemplify the potential of biosphere evolution.

Abstract

Mixed microbial communities, usually composed of various bacterial and fungal species, are fundamental in a plethora of environments, from soil to human gut and skin. Their evolution is a paradigmatic example of intertwined dynamics, where not just the relations among species plays a role, but also the opportunities -- and possible harms -- that each species presents to the others. These opportunities are in fact \textit{affordances}, which can be seized by heritable variation and selection. In this paper, starting from a systemic viewpoint of mixed microbial communities, we focus on the pivotal role of affordances in evolution and we contrast it to the artificial evolution of programs and robots. We maintain that the two realms are neatly separated, in that natural evolution proceeds by extending the space of its possibilities in a completely open way, while the latter is inherently limited by the algorithmic framework it is defined. This discrepancy characterises also an envisioned setting in which robots evolve in the physical world. We present arguments supporting our claim and we propose an experimental setting for assessing our statements. Rather than just discussing the limitations of the artificial evolution of machines, the aim of this contribution is to emphasize the tremendous potential of the evolution of the biosphere, beautifully represented by the evolution of communities of microbes.