Jump to content

VladP

Members
  • Content Count

    6
  • Joined

  • Last visited

Community Reputation

0 Neutral

About VladP

  • Rank
    Lepton

Profile Information

  • Favorite Area of Science
    evolutionary theory
  1. Well, I’m compelled to come directly to the point: the evolution of modular self-replicators is capable of self-learning (by doing). So, biological evolution is an active purposeful process. The prose of informatics and cybernetics. For detail see advertising removed. Enjoy.
  2. Dear Area54, hold your horses. Everything in its own time. Indeed, the idea in question is simple and transparent, yet it is utterly strange. So we are to advance gradually, step by step. And as for natural selection (NS) we’ll get outside of the issue somewhat later. Well, there are two subdivisions in a genome: this operational – and (as yet) the indistinct one. Unlike the former, the latter doesn’t affect the phenotype, and this is why latter subdivisions don’t experience the NS pressure. Therefore, nothing restricts the accumulation of heritable information there: the indistinct subdivisions may widely expand – and they do expand. By Monod, a structure spontaneously evolves due to “… (ii) reproduction … of any accident that occurs in the structure”. At that, a self-replicator reproduces accidents which occur within its genome’s subdivisions – both this operational and this indistinct. Suppose, an instruction accidentally emerges in the latter subdivision: duplicate one or another DNA fragment, within the genome. Such an instruction is far and away less complex than the genetic instructions which control, say, the translation or binary fission processes.
  3. Dear Area54, so far you are missing nothing at all. The idea in question is quite simple and transparent, yet there is hardly a possibility to consistently expound it in a couple of paragraphs. And curiously enough, the Monod’s conditions for spontaneous evolution to proceed don’t involve natural selection. This delicate circumstance deserves special attention. Anyway, I am to continue. For instance, consider prokaryotes that are natural self-replicators. Asexual bacteria satisfy the Monod’s conditions, and so they spontaneously evolve. At that, bacteria fall into the so-called modular self-replicators class. [Eors Szathmary. The Evolution of Replicators. Phil. Trans. R. Soc. Lond. B., 2000] The thing is that in prokaryotic cells, unlike the early syncretic self-replicators, the information modules (genomes) are clearly segregated off those executive, - i.e., off proteins and functional RNAs. Moreover, a bacterial genome comprises, along with coding fragments, some DNA snippets that are identified as these “junk”. In other words, a genome is segregated into two subdivisions: first, this operational which codes proteins and transcribes functional RNAs. And, second, the enigmatic subdivision which part still remains indistinct.
  4. As it seems the ideas of the outstanding microbiologist and evolutionary theorist, 1965 Nobel prize winner, Jacques Monod, 1910-76, may throw some light on the “junk” DNA issue. And they may do upon the paradoxical essence of biological evolution, as well. He has stated way back, that as regards spontaneous evolution, the crucial part is played by “two things: (i) reproduction true to type of the structure itself, and (ii) reproduction equally true to type, of any accident that occurs in the structure. Once you have that, you have evolution, because you have conservation of accidents”. [Le Hasard et la Necessite, 1970. Cit. by Jacques Monod. Chance and Necessity, 1974., p. 394] The two conditions appear clear and laconic, and self-replicators which comply with the Monod’s guidelines spontaneously evolve. Indeed, in the case, self-replication is accompanied by cumulative changes. Therefore, the irreversible process of “descent with modification” takes place that is traditionally associated with spontaneous evolution.
  5. O.K. I’m glad to lend koti assistance: “Each individual is unique. You cannot get evolution selecting between entities when there is only one copy of each entity!” [The Selfish Gene, 1976, p. 34] George C.Williams considered the pernickety issue a decade earlier: “The natural selection of phenotypes cannot in itself produce cumulative change, because phenotypes are extremely temporary manifestations. … The same argument also holds for genotypes. ... Only in species that can maintain unlimited clonal reproduction is it theoretically possible for the selection of genotypes to be an important evolutionary factor.” [Adaptation and Natural Selection, 1966, p. 23-24] See also Evolution: from Mythology to Theory, 2017, by Anatoly Nikolaev (chapter Darwin's Nightmare). In other words, Darwinian natural selection is a phantom, a fiction, in the world of sex… The delicate circumstance is long-standing and well known. In view of this, Dawkins saw right to find a substitute – in the name of NS among “selfish” genes.
  6. I readily share the RiceAWay’s point of view. With his “selfish” gene idea, Richard Dawkins appears an utterly naïve reductionist. He thinks that since a genome is able (granted the support from the proper complex of enzymes, etc.) to reproduce itself as a whole or its fragments, then any part of a genome is also capable of reduplication at its own "will". In the eyes of a systems analyst, such a reasoning seems hardly sound. Indeed, a true system is greater than the sum of its parts, and no part of a system is endowed with all the whole system’s properties. Dawkins is to specially substantiate the ability of a genome’s part to reduplicate at its own “will” - which he wouldn’t do. It is clear why Dawkins was to suggest such a daring idea: in his The Selfish Gene book (chapter 3 Immortal Coils), he conclusively reveals that there is no such appearance as Darwinian natural selection (NS), in the world of sexual reproduction. So he was to look for a substitute and proposed the idea of NS among “selfish” genes. This is quite understandable.
×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.