This research is mainly supported by Grant-in-Aid for Scientific Research (Assignment No.: JP19K23763, JP21H05867, JP15KT0080, JP18H04820, JP20H04859), JST PRESTO (Assignment No.: JPMJPR19KA), Astrobiology Center Project Research (Assignment No. Reference: “Evolutionary transition from a single RNA replicator to a multiple replicator network” by Ryo Mizuuchi, Taro Furubayashi and Norikazu Ichihashi, 18 March 2022, Nature Communications. As Mizuuchi said, “The results could be a clue to solving the ultimate question that human beings have been asking for thousands of years - what are the origins of life?” Of course, there are still many questions left to answer, but this research has provided further empirically based insight into a possible evolutionary route that an early RNA replicator may have taken on primitive Earth. Many more events should occur towards the emergence of living systems.” The evolution of complexity seen in our experiment is just the beginning. So what next? According to Mizuuchi, “The simplicity of our molecular replication system, compared with biological organisms, allows us to examine evolutionary phenomena with unprecedented resolution. They are just molecules, so we wondered if it were possible for nonliving chemical species to spontaneously develop such innovation.” This means that the molecules must establish a way to use different resources one after another for sustained diversification. “In evolutionary biology, the ‘competitive exclusion principle’ states that more than one species cannot coexist if they are competing for the same resources.

“Honestly, we initially doubted that such diverse RNAs could evolve and coexist,” commented Mizuuchi. “We found that the single RNA species evolved into a complex replication system: a replicator network comprising five types of RNAs with diverse interactions, supporting the plausibility of a long-envisioned evolutionary transition scenario,” said Mizuuchi.Ĭompared to previous empirical studies, this new result is novel because the team used a unique RNA replication system that can undergo Darwinian evolution, i.e., a self-perpetuating process of continuous change based on mutations and natural selection, which enabled different characteristics to emerge, and the ones that were adapted to the environment to survive. The team was truly excited by what it saw. When this process was repeated multiple times, mutations occurred. The solution was then diluted to one-fifth the concentration using new droplets containing RNA-free nutrients, and stirred vigorously. RNA molecules were incubated in water-in-oil droplets at 37 degrees Celsius for 5 hours.

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