Researchers report a model for the emergence of RNA polymers on early Earth. Given the widespread presence of RNA in living cells and its ability to store genetic information and self-replicate, RNA likely formed the foundation for the first life on Earth. Two competing hypotheses suggest that RNA might have evolved at hydrothermal vents in the deep ocean or in warm little ponds (WLPs), which have wet and dry cycles that promote nucleotide polymerization into RNA. Ben K. D. Pearce and colleagues constructed a comprehensive numerical model for the evolution of nucleobases, nucleotides, and RNA in WLPs. The model uses sources such as carbonaceous meteorites and interplanetary dust particles to account for the supply of nucleobases to Earth. Additionally, the authors modeled various physical conditions of WLPs from approximately 4.5-3.7 billion years ago, and used two temperatures--65 °C and 20 °C--to represent hot and warm conditions on early Earth. In each scenario, dry, intermediate, and wet environments were modeled. The results indicate that hot conditions supported rapid nucleotide synthesis in WLPs and that RNA polymerization occurred in one to a few WLP wet-dry cycles. According to the authors, the findings suggest that under WLP conditions RNA polymers likely appeared around 4.17 billion years ago.
Article #17-10339: "Origin of the RNA world: The fate of nucleobases in warm little ponds," by Ben K. D. Pearce et al.
MEDIA CONTACT: Ben K. D. Pearce, McMaster University; Hamilton, CANADA; e-mail: <pearcebe@mcmcaster.ca>
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