Self-reproduction

A particularly interesting type of micellar catalysis is the autocatalytic self-replication of micelles [58]. Various examples have been described, but a particularly interesting case is the biphasic self-reproduction of aqueous caprylate micelles [59]. In this system ethyl caprylate undergoes hydroxyl catalysed hydrolysis to produce the free carboxylate anion, caprylate. Caprylate micelles then fonn. As these micelles fonn, they solubilize ethylcaprylate and catalyse further production of caprylate anion and caprylate micelles. 

D) Self-reproduction. Narrowing question (C), can any automaton construct other automata that are exactly like it Can it be made, in addition, to perform further tasks, e.g. also construct certain other prescribed automata ... 

Von Neumann s machine is actually an example of a universal constructor. It must not only carry out logical operations (i.e. act as a universal computer), but must also be able to identify and manipulate various components. The universal constructor C must be able to both (1) construct the machine whose blueprint appears in symbolic form on its input tape and (2) attach a copy of that same blueprint to the machine once it is constructed. Self-reproduction is the special case where C s input tape actually contains the blueprint data for C itself. Alas, there are a few subtleties. 

Using this looser criterion of self-reproduction - it is looser since, unlike von Neumann s requirement, it does not force the self-reproducing structure to be capable of universal construction - Langton discovered a relatively simple self-reproducing structure embedded within a two-dimensional CA that we will refer to as Langton s Loop figure 11.4 shows a few snapshots of its 151 time-step reproduction cycle. 

Self-reproduction without this process, information would be lost after every generation. 

The minimal cell, as the simplest system which has all the required properties of life (metabolism, self-reproduction and the ability to evolve), is presently studied as part of a new research discipline synthetic biology. This includes subjects such as synthesis in branches of biological systems, for example, of new RNA species, new peptides and new nucleic acid analogues, as well as the synthesis of peptide nucleic acids. One example is the work of M. R. Ghadiri and G. von Kiedrowski on self-replication of oligonucleotides and oligopeptides (Luisi, 2006b). 

In the previous pages we have discussed how the increase of molecular complexity may proceed via self-organization, emphasizing, however, that a simple increase of size and/or complexity is not enough - this must he accompanied by the onset of novel properties - up to the point where self-reproduction and eventually life itself arise. In fact, self-organization must be considered in conjunction with corresponding emergent properties. 

If during self reproduction also structural (- function) changes occur, we also have EVOLUTION... 

Also, if the self-replicating structure were to possess chemical information, and in addition the capability to mutate, then self-reproduction, information and evolution would occur all at the same time something already very close to life (see Figure 7.1). It is then clear why the search for self-reproduction mechanisms is the holy grail of the research on the origin of life. 

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