Got a response within hours. Nice. Anyway, here it is.

Although Orgel doesn't use the term "homochirality", he does refer to it in his discussion. Here is the relevant paragraph:

"Equally disappointing, we can induce copying of the original template only when we run our experiments with nucleotides having a right-handed configuration. All nucleotides synthesized biologically today are right-handed. Yet on the primitive earth, equal numbers of right- and left-handed nucleotides would have been present. When we put equal numbers of both kinds of nucleotides in our reaction mixtures, copying was inhibited."

It's toward the end of the article.

Rich Deem

I did a text search on your link with the word, "disappointing" and it took me there immediately.

I really suggest that you read the whole article. It's only a few pages and is for a popular magazine, not a scientific publication, so it's easy to read in 15 minutes even without knowing much about biology or chemistry.

I knew that they were sending you that quote. And for the other 5 or 6 claims they are using the same article as a reference, they'll certainly also give you a 'fitting' one-sentence quote.

If you read the whole article, you'll see that Orgel supports the RNA world theory, and is describing the history and pros and cons of various biogenesis theories and experiments. The quoted passage just relates to a series of experiments for reproducing nucleotide sequences. His article does in no way contain any of the allegations on the website.

This is the typical dishonesty of creationists: using out of context quotes to reverse the meaning of articles. They are scanning through publications by scientists in books, newspapers or magazines, then picking single sentences which, when quoted out of context, seem to be critical of abiogenesis or evolution. They then are using this as a 'reference' for their wild claims.

I suggest that you visit creationist websites with an open mind, check what articles they're using as 'reference', and read them. If you so far believed their allegations, you might experience some surprises.

You will not make similar experiences on evolution websites.

Ok...well here's a good test to see if their claims are really as out their as you claim. Because to me, and I don't want you to take offense to this because it might ruin the friendly nature of this discussion (matt notwithstanding), but it seems you're worried about attacking the source rather than the idea. Which seems pretty typical of evolutionists. Many of them can't win the argument over ideas, so they try to win the war of public opinion, although the way they do it is rather underhanded. (I'm not attributing that motive to you, but the end result not matter what your reasoning is the same. The point of this debate isn't, "How reliable are creationists?" Its how is abiogenesis possible?)

Anyways, here's the way to test whether or not their claims are really out there or not. Just refer to a way in which homochirality can be acheived. Because I don't see how Orgel's comments are taken out of context. Orgel isn't critical of abiogenesis, he's just admitting to a shortcoming. 'God and Science' didn't seem to imply that Orgel didn't subscribe to the possibility of abiogenesis, or that he was critical of it, they seemed to imply that he admitted to the hurdle of acheiving homochirality.

It is normally assumed that homochirality was the result of a reproduction/selection process. Once you have a self-replicating peptide, it will replicate its original handedness. As this replication process continues and builds more complex polymeres, you can imagine that they will reflect the chirality of that first replicating peptide.

Leslie Orgel in his article suggest another mechanism: Self-assembly on two-dimensional surfaces, like clay or minerals. This also can lead to the domination of a certain handedness.

The above mentioned homochirality mechanism by reproduction was experimentally verified in 2001. See http://www.scripps.edu/news/press/021401.html.

I did attack the website not only because of its obviously wrong statements, but also because of its dishonesty. I think "attacking the source" is justified in such a case.

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That would skip the step of acheiving homochirality.

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Homochirality is not a step, but the result of the process. The very first peptide replicator has a certain chiralitly - with a chance of 50% it is left-handed. It then reproduces and consumes the amino acids in its environment. The reproduction of a similar right-handed replicator is then suppressed by the predominance of the earlier left-handed replicator.

I can't comment on the 'optically active biomolecules' because I am not aware of their role in biogenesis.

Just a quick question for anyone: what does this discussion of homochirality actually have to do with abiogenesis, and whether or not it is possible? It seems the issue has been lost in technical details no one here really is qualified to discuss in detail..

The discussion arose about an allegation on that creationist website that homochirality can not be achieved in a natural way and requires some supernatural intervention.

Left or right handedness refers not to the refraction, but to the polarization of light. Light passing the substance is circular polarized. But I fail to understand the argument about the 'optically active' molecules.

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homochirality can not be achieved in a natural way and requires some supernatural intervention.

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I see..

While I'm not qualified to discuss complex issues of organic chemistry, my simple refutation of this would be something like this: since homochirality is observed in nature, it seems obvious that it can occur naturally. QED.

Regardless of how hard it is to imagine such structural organization forming naturally, many things in nature have a complex organization, such as crystals, lattices, and even fullerene structures. It seems short-sighted to assume that homochirality can't also occur naturally, given that we have billions of years of organic soup bubbling away.

These lines of reasoning, regardless of what technical jargon may used, all boil down to one basic argument: things we cant imagine forming naturally--becasue we havent observed it happening--must have been caused by a god. This is faulty reasoning because it supposes that we know everything about how natural processes work, and that because we cant directly observe something, it cant have happened naturally.

Therefore, if organic structures arise with a given organizational complexity, we should NOT assume that it is related to a supernatural cause, but instead assume that it is natural, and try to understand how it occurs. This is the basis of all science; as I have said before, science can only prceed when the supernatural is ruled out at once.

There is really not much more to say here I think; either you agree with the scientific method, or you dont. If you dont, please dont bother arguing with a scientist or a theory.