Origins of Life: Chemistry and Evolution

Progress in understanding the origins of life will be enhanced if models and their predictions are clearly understood and explicitly articulated. Two distinct models can be used to explain the genesis of biopolymers during the origins of life. In one model, which has been pursued for nearly 50 years, RNA is the result of inherent chemical reactivities of prebiotic chemical species. RNA invented evolution. This model enables the prediction that if the conditions of the ancient earth are sufficiently constrained, chemists will discover the direct synthetic pathways that produced RNA. In a fundamentally different model, which is more recent, RNA and other biopolymers are proposed to be the result of prolonged, creative, selection-based changes that occurred during chemical evolution and overlap with early biological evolution. Evolution invented RNA. In this evolutionary model, inherent chemical reactivities are not necessarily relevant to the origins of life and do not predict biosynthesis. These two models are fundamentally different from one another and guide design of very different experimental approaches to test their underlying assumptions. It is currently undetermined which model, or a hybrid of them, is closer to reality.