A Caltech Library Service

Defining Lyfe in the Universe: From Three Privileged Functions to Four Pillars

Bartlett, Stuart and Wong, Michael L. (2020) Defining Lyfe in the Universe: From Three Privileged Functions to Four Pillars. Life, 10 (4). Art. No. 42. ISSN 2075-1729. PMCID PMC7235751. doi:10.3390/life10040042.

[img] PDF - Published Version
Creative Commons Attribution.


Use this Persistent URL to link to this item:


Motivated by the need to paint a more general picture of what life is—and could be—with respect to the rest of the phenomena of the universe, we propose a new vocabulary for astrobiological research. Lyfe is defined as any system that fulfills all four processes of the living state, namely: dissipation, autocatalysis, homeostasis, and learning. Life is defined as the instance of lyfe that we are familiar with on Earth, one that uses a specific organometallic molecular toolbox to record information about its environment and achieve dynamical order by dissipating certain planetary disequilibria. This new classification system allows the astrobiological community to more clearly define the questions that propel their research—e.g., whether they are developing a historical narrative to explain the origin of life (on Earth), or a universal narrative for the emergence of lyfe, or whether they are seeking signs of life specifically, or lyfe at large across the universe. While the concept of “life as we don’t know it” is not new, the four pillars of lyfe offer a novel perspective on the living state that is indifferent to the particular components that might produce it.

Item Type:Article
Related URLs:
URLURL TypeDescription CentralArticle
Bartlett, Stuart0000-0001-5680-476X
Additional Information:© 2020 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license ( Received: 23 March 2020; Accepted: 13 April 2020; Published: 16 April 2020. We extend our heartfelt thanks to the members of the Caltech Astrobiology Reading Group, with whom many of the ideas in this paper were passionately discussed. Author Contributions: Discussions between the authors over an extended period culminated in the presented work. S.B. conceived of the four pillars concept, M.L.W. produced all the figures and wrote various sections of the manuscript. All authors have read and agreed to the published version of the manuscript. This research received no external funding. The authors declare no conflict of interest.
Subject Keywords:definition of life; origin of life; astrobiology; mechanotroph
Issue or Number:4
PubMed Central ID:PMC7235751
Record Number:CaltechAUTHORS:20200417-125836268
Persistent URL:
Official Citation:Bartlett, S.; Wong, M.L. Defining Lyfe in the Universe: From Three Privileged Functions to Four Pillars. Life 2020, 10, 42.
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:102602
Deposited By: Tony Diaz
Deposited On:17 Apr 2020 20:06
Last Modified:16 Nov 2021 18:13

Repository Staff Only: item control page