Formalising the pathways to life using assembly spaces

Marshall, S. M., Moore, D. G., Murray, A. R.G., Walker, S. I. and Cronin, L. (2022) Formalising the pathways to life using assembly spaces. Entropy, 24(7), 884. (doi: 10.3390/e24070884) (PMID:35885107) (PMCID:PMC9323097)

Abstract

Assembly theory (referred to in prior works as pathway assembly) has been developed to explore the extrinsic information required to distinguish a given object from a random ensemble. In prior work, we explored the key concepts relating to deconstructing an object into its irreducible parts and then evaluating the minimum number of steps required to rebuild it, allowing for the reuse of constructed sub-objects. We have also explored the application of this approach to molecules, as molecular assembly, and how molecular assembly can be inferred experimentally and used for life detection. In this article, we formalise the core assembly concepts mathematically in terms of assembly spaces and related concepts and determine bounds on the assembly index. We explore examples of constructing assembly spaces for mathematical and physical objects and propose that objects with a high assembly index can be uniquely identified as those that must have been produced using directed biological or technological processes rather than purely random processes, thereby defining a new scale of aliveness. We think this approach is needed to help identify the new physical and chemical laws needed to understand what life is, by quantifying what life does.

• Item Type: Articles
• Additional Information: We acknowledge financial support from the John Templeton Foundation (grants 60625, 61184 and 62231), EPSRC (grant nos. EP/L023652/1, EP/R01308X/1, EP/S019472/1, and EP/P00153X/1), the Breakthrough Prize Foundation, NASA (Grants 80NSSC18K1140 and GR40991) and ERC (project 670467 SMART-POM).
• Keywords: Graphs, biosignatures, complexity, information.
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Murray, Alastair and Marshall, Stuart and Cronin, Professor Lee
• Authors: Marshall, S. M., Moore, D. G., Murray, A. R.G., Walker, S. I., and Cronin, L.
• College/School: College of Science and Engineering; College of Science and Engineering > School of Chemistry
• Journal Name: Entropy
• Publisher: MDPI
• ISSN: 1099-4300
• Published Online: 27 June 2022
• Copyright Holders: Copyright © 2022 The Authors
• First Published: First published in Entropy 24(7): 884
• Publisher Policy: Reproduced under a Creative Commons License

Related URLs

• Pre-print

Project Code	Award No	Project Name	Principal Investigator	Funder's Name	Funder Ref	Lead Dept
173546		A molecular complexity approach to identifying bio-signatures, shadow-life, and new life forms	Leroy Cronin	John Templeton Foundation (TEMPLFOU)	60625	Chemistry
190796		Programmable 'Digital' Synthesis for Discovery and Scale-up of Molecules, Clusters and Nanomaterials	Leroy Cronin	Engineering and Physical Sciences Research Council (EPSRC)	EP/L023652/1	Chemistry
300591		Programmable Molecular Metal Oxides (PMMOs) - From Fundamentals to Application	Leroy Cronin	Engineering and Physical Sciences Research Council (EPSRC)	EP/R01308X/1	Chemistry
303747		Digital-Chemical-Robotics for Translation of Code to Molecules and Complex Chemical Systems	Leroy Cronin	Engineering and Physical Sciences Research Council (EPSRC)	EP/S019472/1	Chemistry
172957		Advanced Mass Spectrometry Kit for Controlling Chemical Robots and Exploring Complex Chemical Systems	Leroy Cronin	Engineering and Physical Sciences Research Council (EPSRC)	EP/P00153X/1	Chemistry
172151		SMARTPOM: Artificial-Intelligence Driven Discovery and Synthesis of Polyoxometalate Clusters	Leroy Cronin	European Research Council (ERC)	670467	Chemistry