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Krasnow Institute > Monday Seminars > Abstracts Inheritance Without Biopolymers in a Computer Model for Primordial Evolution Daniel Segre' Research indicates that all existing life on earth originated some 3.7 billion years ago from a common cellular precursor. Yet, the question of how the first living cell, with its complex biochemical mechanisms, came into being, remains a profound mystery. In parallel to the standard organic chemistry approaches to the origin of life, scientists from various disciplines have been trying to investigate biogenesis by theoretical modeling. Many of these models describe complex chemical interactions within assemblies of organic molecules, or their abstract representations, prior to the emergence of DNA, RNA and proteins. They purport to demonstrate how a transition could occur from early random mixtures of organic molecules to the first protocell. We have recently developed a model, which provides a kinetic analysis of mutually catalytic assemblies combined with statistical tools. By Monte Carlo simulations, we study the spontaneous emergence of assemblies with idiosyncratic molecular compositions, capable of carrying information, as well as of undergoing rudimentary self-replication and chemical evolution. We suggest that early on, "compositional genomes" could serve the same purpose as the currently active sequential genome. This model demonstrates how self-replication may be a property of a molecular ensemble, without any specific constraints on the structure of the components. No individual molecule needs to be endowed with the specialized chemical properties currently associated with replicating macromolecules such as DNA and RNA. Only at later stages would molecular aggregates gradually "discover" the advantages of an alphabet-based digital information storage mechanism.
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