Ik verwijs nogmaals naar
het artikel van orgel die je blijkbaar nog steeds niet gelezen hebt.
Problemen:
Mogelijk is niet goed genoeg:
It must be recognized that assessment of the feasibility of any particular proposed prebiotic cycle must depend on arguments about chemical plausibility, rather than on a decision about logical possibility. ... Each proposed metabolic cycle, therefore, must be evaluated in terms of the efficiencies and specificities that would be required of its hypothetical catalysts in order for the cycle to persist. Then arguments based on experimental evidence or chemical plausibility can be used to assess the likelihood that a family of catalysts that is adequate for maintaining the cycle could have existed on the primitive Earth.
Op papier is niet goed genoeg:
It is a catalytic cycle in which a complicated sequence of enzymatic reactions is used to bring about indirectly a reaction that looks simple on paper, but is not easily achieved in practice.
Tijd alleen is niet voldoende
However, the identification of a cycle of plausible prebiotic reactions is a necessary but not a sufficient step toward the formulation of a plausible self-organizing prebiotic cycle. The next, and more difficult step, is justifying the exclusion of side reactions that would disrupt the cycle.
Efficientie?
The cycle could not survive if side reactions funneled off more than half of the cycle components irreversibly, because then the concentration of the cycle components would decline exponentially to zero.
Het geheel is maar zo sterk als de zwakste schakel:
However, the reactions are not independent because each reaction is pulled toward completion by the use of its product as the input for the subsequent reaction of the cycle.
Thermodynamica:
Any catalyst or family of catalysts that could convert isocitric acid to citric acid could also achieve the reverse reaction. Whatever the original input, one would finish with an equilibrium mixture, the composition of which is determined by thermodynamics.
Verliezen...
A possibly more serious problem is posed by the difficult reductive carboxylation reactions. If they proceed with acetic acid and succinic acid as inputs they might be expected to accept malic acid as an equivalent input. This reaction would move material irreversibly out of the cycle, so one must postulate a specific catalyst that discriminates between succinic and malic acid.
Hoewel biologische enzymen zeer specifiek zijn kan dat niet wordt aangenomen voor prebiotische katalysatoren.
One needs, therefore, to postulate highly specific catalysts for these reactions. It is likely that such catalysts could be constructed by a skilled synthetic chemist, but questionable that they could be found among naturally occurring minerals or prebiotic organic molecules.
Handwaving is niet voldoende?
Wächtershäuser no longer attributes importance to surface metabolism and the reverse citric acid cycle, replacing them as a source of self-organization by metabolic reproduction, evolution, and inheritance by ligand feedback. Unfortunately he never explains, even in outline, how this mechanism could lead to the synthesis of the aminoacyl-nucleotide conjugates that seem to be an essential feature of the proposal.
....
Merk op dat die pagina waar je naar verwijst inderdaad de verwijst naar het zelfde Ghadiri experiment dat volgens Orgel op dit moment slechts als een voorbeeld van ID kan worden gebruikt.
These findings, however, cannot support Kauffman's theory unless the prebiotic synthesis of the specific 15mer and 17mer input peptides from monomeric amino acids can be explained. Otherwise, Ghadiri's experiments illustrate intelligent design of input peptides, not spontaneous self-organization of polymerizing amino acids. This takes us to the core of the problem: do sets of peptides of length approximately ten exist that have the ability to constitute a cycle and, even more importantly, could they and their subsequences specifically catalyze their own formation from a mixture of amino acids?
Overigens wordt in deze essay heel Kauffman's (puur mathematisch) voorstel van peptide cycli weggevaagd.
The catalytic properties of enzymes are remarkable. They not only accelerate reaction rates by many orders of magnitude, but they also discriminate between potential substrates that differ very slightly in structure. Would one expect similar discrimination in the catalytic potential of peptides of length ten or less? The answer is clearly no, and it is this conclusion that ultimately undermines the peptide cycle theory.
Lees het artikel van Orgel eens aandachtig door en lees dan nog eens dat artikel van talk origin... let op hoe men aanneemt zonder enige bewijs dat er eenvoudiger levensvormen moeten zijn geweest, waarbij ze letterlijk hun theorie tot feit verheven.
En dan nog het volgende mythe:
veel tijd + kleine veranderingen = grote veranderingen
Met andere woorden als ik van af vandaag elke dag 10 euro munten op elkaar stapel dan heb ik over een jaar een toren van 3650 munten? Of denk je dat deze voordien omvalt? Zouden er wellicht beperkingen kunnen zijn aan wat mogelijk is? Maw.. Bewijs eerst maar eens dat het mogelijk is voor je ervan uitgaat en het gebruikt als verklaring.
Any sufficiently analyzed magic is indistinguishable from science.
Any sufficiently advanced technology is indistinguishable from magic.
There is no theory of protecting content other than keeping secrets Steve Jobs
Puzzels
