Posted: Apr 13, 2010 4:12 pm
rainbow wrote:Rumraket wrote:rainbow wrote:Rumraket wrote:
Before we can try and look for indirect evidence, we must first define what that would be. In the case of Primordial Soup, what is that, specifically?
Well according to some hypotheses, the early earth was awash with high concentrations of organic compounds.
Now depending on which hypothesis you believe, these compounds differ, as does their origin.
As I don't know which is your favourite, and I've no favourite, I can't really point to the hypothesis for which we are looking for supporting evidence. Can I?
Your choice.
Well I can't really pick one either.
The best I can do is more or less to try and read up on what the "general consensus" in abiogenesis research is, if there even is such a thing. I actually don't think there is.
Perhaps then you can appreciate my irritation with people that wave at the 78 Papers, and state that the evidence is there, when these papers represent very diverse hypotheses wrt. Abiogenesis.
I can identify half-a-dozen scenarios, and they have some laboratory work to show that they are possible.
...but they cannot be all correct.
Therefore which evidence of possibility do we take?
First of all, it seems most of those 88 papers lend support to a preRNA->RNA world hypothesis. There are papers on the formation of ribonucleotides, oligomers and polymers under various conditions. There are papers on the evolvability of simple self-replicators.
Another large portion of them seems to deal with abiotic amino-acid formations. This could also be relevant for the evolution of the first lifeforms in an RNA-world when they propapbly didn't start out with the ability to synthesise these themselves(since this already requires complex genetic and protein machinery).
There are several papers on actual evidence for the existence of various relevant(to an RNA world) organic compounds in ancient rocks, meteorites, interstellar dust etc. etc.
There are a few papers discussing the formation of lipids, which can also be relevant to an RNA world model.
It actually fits quite well together if you bothered to look at it a little more than just the titles. Tie this in with many other papers that have been discussed on this site and elsewhere, and it actually seems like there is substantial support for something like a preRNA->RNA world.
If someone points you to these papers and states there is evidence here, it's because there is.