Molecular replication

Feeding can be avoided in the previous experiments if the molecular replication process at a surface is coupled with chromatographic separation. The two building blocks A and B are added to the mobile phase, while the matrices C are formed at the surface of the stationary phase. The main difference from the process described previously is that the matrices are not bonded covalently to the surface, but reversibly. During elution (which supplies new building block molecules to the system) a certain amount of matrix molecules is washed off and must be replaced by replication (von Kiedrowski, 1999). 

Orgel, L.E. (1987). Evolution of the genetic apparatus. A review. Cold Spring Harbor Symposia on Quantitative Biology, Vol. 52, pp. 9-16. Cold Spring Harbor Laboratory, Cold Spring Harbor, NY. Orgel, L.E. (1992). Molecular replication. Nature (London) 358,203-209. 

Likewise, we can easily conceive of robots that are self-reproducing or computer-based processes that grow and replicate.13 Here, information transfer is not based on a specific molecular replication but on a replication involving information on a matrix. Whether such entities will be called life remains to be seen. 

The first scientific theories on the origin of life were proposed by Alexander Oparin in 1924 and by J.B.S. Haldane in 1929. Oparin discovered that a solution of proteins can spontaneously produce microscopic aggregates - which he called coacervates - that are capable of a weak metabolism, and proposed that the first cells came into being by the evolution of primitive metabolic coacervates. Haldane, on the other hand, was highly impressed by the replication properties of viruses, and attributed the origin of life to the evolution of viruslike molecular replicators. 

The discovery of viruses made an enormous impression on biologists, because it proved that something much smaller than a cell maintained the ability to replicate, the most quintessential of life s properties. Haldane knew only too well that viruses are totally dependent on cells for their replication, and therefore that they could have evolved only after cells, but those tiny proliferating crystals in the interior of huge cellular structures appeared to state a deeper truth that replication is simpler than metabolism. This was the concept that struck Haldane, and from that came the idea that everything started when the first molecular replicators appeared on the primitive Earth. 

Life, as we know it, is based on replication, which on a molecular level is realized by DNA base pairing. However, the scheme with four nucleobases of DNA does not necessarily represent the only way to achieve molecular replication [1], Furthermore, there are alternate pairing schemes and structures and interactions between the bases that can lead to mutations, for example by proton transfers that lead to different tautomers. For all these reasons the study of interactions between individual nucleobases and of the properties of isolated base pairs at the most fundamental level is important and such studies are possible in the gas phase. 

Complementariness remained on Pauling s mind, and in 1948, he discussed molecular replication [75] ... 

As shown above, molecular replication is simply an autocatalytic reaction where the product of a chemical transformation acts to catalyze that... 

Bag, Braja Gopal, and Gunter von Kiedrowski. Templates, Autocatalysis and Molecular Replication. Pure Applied Chemistry 68 (1996) 2,145-52. This accessible article provides principles of molecular self-replication and describes investigations in the field. 

Bag BG, von Kiedrowski G (1996) Templates, autocatalysis and molecular replication. Pure ApplChem 68 2145-2152... 

Four billion years ago the seeds of life had been firmly planted. The Archean Earth boasted substantial repositories of serviceable organic molecules, which became locally concentrated and assembled into vesicles and polymers of biological interest. Once the first molecular replicator emerged, molecular natural selection took off. In such a world, nascent biology and ancient geochemistry became inextricably entwined. For example, Earth s surface mineralogy diversified as a result of varied microbial influences, which altered ocean and atmospheric chemistries at scales from local to global (2). 

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