computer simulation on the cooperation of functional molecules during the early stages of evolution计算机模拟在功能性分子的合作进化的早期阶段.pdf

Computer Simulation on the Cooperation of Functional Molecules during the Early Stages of Evolution 1 2 Wentao Ma *, Jiming Hu 1 College of Life Sciences, Wuhan University, Wuhan, Hubei, China, 2 College of Chemistry and Molecular Sciences, Wuhan University, Wuhan, Hubei, China Abstract It is very likely that life began with some RNA (or RNA-like) molecules, self-replicating by base-pairing and exhibiting enzyme-like functions that favored the self-replication. Different functional molecules may have emerged by favoring their own self-replication at different aspects. Then, a direct route towards complexity/efficiency may have been through the coexistence/cooperation of these molecules. However, the likelihood of this route remains quite unclear, especially because the molecules would be competing for limited common resources. By computer simulation using a Monte-Carlo model (with ‘‘micro-resolution’’ at the level of nucleotides and membrane components), we show that the coexistence/ cooperation of these molecules can occur naturally, both in a naked form and in a protocell form. The results of the computer simulation also lead to quite a few deductions concerning the environment and history in the scenario. First, a naked stage (with functional molecules catalyzing template-replication and metabolism) may have occurred early in evolution but required high concentration and limited dispersal of the system (e.g., on some mineral surface); the emergence of protocells enabled a ‘‘habitat-shift’’ into bulk water. Second, the protocell stage started with a substage of ‘‘pseudo-protocells’’, with functional molecules catalyzing template-replication and metab