Dynamics of prebiotic RNA reproduction illuminated by chemical game theory.
Many origins-of-life scenarios depict a situation in which there are common and potentially scarce resources needed by molecules that compete for survival and reproduction. The dynamics of RNA assembly in a complex mixture of sequences is a frequency-dependent process and mimics such scenarios. By synthesizing Azoarcus ribozyme genotypes that differ in their single-nucleotide interactions with other genotypes, we can create molecules that interact among each other to reproduce. Pairwise interplays between RNAs involve both cooperation and selfishness, quantifiable in a 2 × 2 payoff matrix. We show that a simple model of differential equations based on chemical kinetics accurately predicts the outcomes of these molecular competitions using simple rate inputs into these matrices. In some cases, we find that mixtures of different RNAs reproduce much better than each RNA type alone, reflecting a molecular form of reciprocal cooperation. We also demonstrate that three RNA genotypes can stably coexist in a rock-paper-scissors analog. Our experiments suggest a new type of evolutionary game dynamics, called prelife game dynamics or chemical game dynamics. These operate without template-directed replication, illustrating how small networks of RNAs could have developed and evolved in an RNA world.
Department of Chemistry, Portland State University, Portland, OR 97207;
Jessica A M
JA
Yeates
Program for Evolutionary Dynamics, Harvard University, Cambridge, MA 02138;
Christian
C
Hilbe
Systems Science Graduate Program, Portland State University, Portland, OR 97207.
Martin
M
Zwick
Program for Evolutionary Dynamics, Harvard University, Cambridge, MA 02138;
Martin A
MA
Nowak
Department of Chemistry, Portland State University, Portland, OR 97207; niles@pdx.edu.
Niles
N
Lehman
D003198:Computer Simulation; D019418:Evolution, Chemical; D005716:Game Theory; D007700:Kinetics; D008956:Models, Chemical; D008957:Models, Genetic; D015233:Models, Statistical; D000069497:Origin of Life; D016337:RNA, Catalytic / Q000737:chemistry*
D016337:RNA, Catalytic
RNA; game theory; origins of life; prebiotic chemistry; ribozyme