The Emergence of Life as a First-Order Phase Transition.
It is well known that life on Earth alters its environment over evolutionary and geological timescales. An important open question is whether this is a result of evolutionary optimization or a universal feature of life. In the latter case, the origin of life would be coincident with a shift in environmental conditions. Here we present a model for the emergence of life in which replicators are explicitly coupled to their environment through the recycling of a finite supply of resources. The model exhibits a dynamic, first-order phase transition from nonlife to life, where the life phase is distinguished by selection on replicators. We show that environmental coupling plays an important role in the dynamics of the transition. The transition corresponds to a redistribution of matter in replicators and their environment, driven by selection on replicators, exhibiting an explosive growth in diversity as replicators are selected. The transition is accurately tracked by the mutual information shared between replicators and their environment. In the absence of successfully repartitioning system resources, the transition fails to complete, leading to the possibility of many frustrated trials before life first emerges. Often, the replicators that initiate the transition are not those that are ultimately selected. The results are consistent with the view that life's propensity to shape its environment is indeed a universal feature of replicators, characteristic of the transition from nonlife to life. We discuss the implications of these results for understanding life's emergence and evolutionary transitions more broadly. Key Words: Origin of life-Prebiotic evolution-Astrobiology-Biopolymers-Life. Astrobiology 17, 266-276.
1 Department of Physics, Arizona State University , Tempe, Arizona.
Cole
C
Mathis
2 Santa Fe Institute , Santa Fe, New Mexico .|3 Los Alamos National Laboratory , Los Alamos, New Mexico .
Tanmoy
T
Bhattacharya
4 Beyond Center for Fundamental Concepts in Science and School of Earth and Space Exploration, Arizona State University , Tempe, Arizona.|5 Blue Marble Space Institute of Science , Seattle, Washington.
Sara Imari
SI
Walker
D000069497:Origin of Life; D044367:Phase Transition; D013997:Time Factors