beausoleil

Gee, did I say 'we'! I had to get to grips with the distinction for a research project a while back but am far from an expert. I'd made the mistake of assuming all algae were prokaryotes because blue-green algae were.

Actually it was only about then I found out what prokaryotes and eukaryotes were.

lpetrich

I should have made it clearer -- it's only the last few paragraphs of my original posting, the part about looking backward, that summarize that 57-page Brian Davis paper.

I would also like to post an illustration of that reconstructed structure of a tailed ferredoxin molecule; would doing so be a copyright violation?

Paul

can anyone actualy give me the probability of life arising ?
links? lastest research proving it really could of happened.

Asha'man

I think the simple answer is: NO.

In order to compute a meaningful probability, you have to understand all possible paths to the outcome you are looking for.

Since our understanding of even a single path (the one that actually happened on earth) is still somewhat speculative, any such probability would be nothing but a guess.

Anyone who tells you otherwise is probably lying.



On the other hand, life did arise at least once, so the probability is exactly 1.

Wyz_sub10

You are working the math backwards here. As I noted in another link, you cannot determine another reasonable by reversing an event that happened and debate its probability.

You received a hand of five cards. *That hand* is very, very improbable. But this says nothing unless you considered that hand the desired outcome of goal.

Life was not a desired outcome of goal. It just happened. So as Asha'man noted, the probability is 1 (or 100%).

If you had competing hypotheses, then probability might come into play (i.e. what's more likely - 1) the Mona Lisa in your basement was stolen and brought there, 2) space aliens beemed the painting from the Louvre to your basement, 3) the painting grew legs and walked there itself).

But while the origins of life have competing scientific theories, none of them have such a decided probabilistic advantage as to make all others seem ridiculously unlikely.

So determining the probability of theory 'A' doesn't at all answer whether it *could* have happened. Rather, it may strengthen or weaken it's position versus theory 'B' or 'C'.

gilly54

Paul asks:
I remember my first post upon becoming an II member was very similar to this. Lpetrich pointed me to the experiments done by Stanley Miller. Prof. Miller tried to reproduce the atmosphere of the early Earth in his laboratory and found that in a short period of time, he created amino acids.

Does anyone know if any other experiments took Prof. Miller's work further?

lpetrich

Giving a number to the origin-of-life probability is EXTREMELY difficult; I've yet to see anyone seriously propose such a number.

And in answer to gilly54's question, there have been numerous prebiotic-chemistry experiments since Stanley Miller's pioneering experiment; it's possible to get good yields of organic molecules with a variety of techniques and starting conditions. Checking PubMed, I find numerous papers on "prebiotic chemistry" (537) and "prebiotic synthesis" (326).

In fact, I once knew someone who had done prebiotic-chemistry experiments, working with a simulation of the atmosphere of Saturn's satellite Titan. Among the substances formed was a reddish-brown goo -- a goo which is the color of Titan's clouds.

So I'm not sure where to start.

LordSnooty

I have, once. A Christian statistician. I forget his name, but I understand he was pretty famous. I think he died last year.

Anyway, he came up with this number, presumably one that he had pulled from his backside, and I have seen it quoted by evolution deniers. Since this guy was a mathematician of some variety I think they believe that his probability rating is reliable, which it obviously isn't.

So far as I know, he may have taken the secret behind this amazing calculation to his grave.

Paul