The Last Conformist said:
Couple points:
I'm not aware of any reason that protein necessarily was present in the first life (or proto-life), still less that any primeval proteins must have been the size of modern ones.
What I know about the metabolism of cells makes it difficult to imagine how anything without proteins should be considered alive. But I am intersted in the scenario you'd consider reasonably possible.
DNA-RNA first? Even much more complicated molecule to develope by chance- not only AS but sugar and nucleotids. A C T and G are also quite complex I'd say.
Viruses? They posses a hull of proteins, so still as above.
I am all my ears errr- eyes in this case
The Last Conformist said:
The limited life-span of the compounds in question is only relevant to the extent they were not continuously regenerated..
Sounds logical. But he life time of a proto-protein wouldn't be long. Against all the odds the appearances of proteins (or DNA, RNA, whatever you imagine as a starting point of life) does not seem to be as probable as that a continuous synthesis can be considered. Can it? Even Miller yielded only very small concentrations of AS, hardly enough to strengthen your argument.
The Last Conformist said:
Chirality looks like a "frozen accident". If life arose "by chance" from an organic primaeval broth, all that's needed is that the first replicator randomly chose L chirality for all descendant life to retain it.
This is in fact all what is needed. But if you have brown and white bricks and you want to build them a house by change you would consider the house to be in two colours. Not?
Where should be a reason to restrict to only L- form if both are available? Even more if you consider this "soup" be not as rich of proteins that you may easily waste one half. Again "by chance"?
For this theorie there are so many "by chance" and each one with a very low propability in fact, that the summ of them sounds like most propably not!
But bacause of your
If it seems you're also not definetaly convinced about the abiogenesis or am I wrong?
Anyway, here it is not possible to bring indeed hard evidence, hence one must consider what seems to be the most propable.
One version might be that life can in fact not appear on earth but on another systems planet and the seeds were planted through a comet's impact? Also thinkable, isn't it? Theoretically bacterial spores may be able to survive such a travel.
This sounds even more reasonable than the spontanous origin of life under the presumed conditions on earth IMO.