Barak Shenhav * , † , Aia Oz and Doron Lancet
نویسندگان
چکیده
The coevolution of environment and living organisms is well known in nature. Here, it is suggested that similar processes can take place before the onset of life, where protocellular entities, rather than full-fledged living systems, coevolve along with their surroundings. Specifically, it is suggested that the chemical composition of the environment may have governed the chemical repertoire generated within molecular assemblies, compositional protocells, while compounds generated within these protocells altered the chemical composition of the environment. We present an extension of the graded autocatalysis replication domain (GARD) model—the environment exchange polymer GARD (EE-GARD) model. In the new model, molecules, which are formed in a protocellular assembly, may be exported to the environment that surrounds the protocell. Computer simulations of the model using an infinite-sized environment showed that EE-GARD assemblies may assume several distinct quasi-stationary compositions (composomes), similar to the observations in previous variants of the GARD model. A statistical analysis suggested that the repertoire of composomes manifested by the assemblies is independent of time. In simulations with a finite environment, this was not the case. Composomes, which were frequent in the early stages of the simulation disappeared, while others emerged. The change in the frequencies of composomes was found to be correlated with changes induced on the environment by the assembly. The EE-GARD model is the first GARD model to portray a possible time evolution of the composomes repertoire.
منابع مشابه
The Lipid World: from Catalytic and Informational Headgroups to Micelle Replication and Evolution without Nucleic Acids Arren Bar-even, Barak Shenhav, Ran Kafri and Doron Lancet
متن کامل
Coevolution of compositional protocells and their environment.
The coevolution of environment and living organisms is well known in nature. Here, it is suggested that similar processes can take place before the onset of life, where protocellular entities, rather than full-fledged living systems, coevolve along with their surroundings. Specifically, it is suggested that the chemical composition of the environment may have governed the chemical repertoire ge...
متن کاملLipidia: An Artificial Chemistry of Self-Replicating Assemblies of Lipid-like Molecules
Lipidia is a new simulation system that is related to the “Lipid World” scenario for the origin of life. Lipidia allows for conducting experiments with a population of assemblies containing lipid-like molecules on a two dimensional grid. The dynamics of the assemblies is modelled using the Graded Autocatalysis Replication Domain (GARD) model. New experiments using a finite environment model wit...
متن کاملMesobiotic Emergence: molecular and Ensemble Complexity in Early Evolution
In addition to the visible complexity expressed in the morphogenesis of multicellular organisms, two levels of microscopic complexity may be discerned within every living cell. The first level is related to covalently bonded structures, namely molecules. The second level has to do with the generation of non-covalent molecular assemblies. Origin of life research has largely focused on the first ...
متن کاملEarly Systems Biology and Prebiotic Networks
Systems Biology constitutes tools and approaches aimed at deciphering complex biological entities. It is assumed that such complexity arose gradually, beginning from a few relatively simple molecules at life’s inception, and culminating with the emergence of composite multicellular organisms billions of years later. The main point of the present paper is that very early in the evolution of life...
متن کامل