Time to continue slogging through this… so…
4. The Problem of Reactivity
In this 4th section, McComb’s gradually tries to get into a little bit of abiogenesis and evolutionary biology. And again, he seems to mix the two up entirely, applying the conditions and pre-requisites for one to the other. So, let’s get this clear: abiogenesis is how life gets started, evolutionary biology is what happens once it has and natural selection can get involved. Importantly, abiogenesis has no requirement that an amino acid chain that has formed from a hypothetical “primordial soup” has a purpose. Purpose and function is something that comes later, once selection criteria have been able to refine the process. This is why evolutionary biologists that have to defend themselves against creationists and design advocates say that abiogenesis and evolution are different things, and that evolution has no need to explain abiogenesis. One works on refining information (information that exists as an abstract isomorphism with a chemical compound) and the other simply gets us to that chemical compound, and any variant of it that it likes.
So, the core claim of this section can be summed up in this sentence:
The product of natural or random reactions could never provide the precise sequences found in proteins and DNA/RNA.
But, as I said, they don’t have to. At this stage, what we’re calling “life” doesn’t serve a particular function. Now, I could go into how McComb’s is ballsing up reactivity and rates of reaction again, but I actually want to blow my word count on this very important revelation. I will put it in large, centred, capital letters and bold text just to make it clear:
ABIOGENESIS IS A PROCESS NOT AN EVENT
This means that there is no magic sudden spark that generates life. No one studying or theorising the early stages of life (studying it seriously, that is) has ever proposed differently. Life is a continuum, working its way up slowly from simple chemicals to complex chemicals – from disorder to order, from less organised information to more organised information (this is in an “information theory” sense, I direct anyone with a problem with this to this article). There is no sudden barrier that delineates life from non-life, and there certainly isn’t one in abiogensis. This is an important subtly that few really get, and creationists actively exploit this lack of understanding when trying to sell their wares to an unsuspecting population. In fact, “life”, as a thing, is an illusion (yes, this is an extreme over-interpretation of a very subtle point, but it makes headlines). “Life” is really just a mental (and linguistic) short-cut that differentiates between things that we can eat or could eat us, and things that can’t. A rock? Can’t eat us, we can’t eat it; not alive. That deer over there? We can eat it or it could eat us; alive. It serves us well because if we had to apply too much thinking to it, we would die pretty quickly. When it comes to edge cases, our intuitive of what is “alive” breaks down – and we think it’s a problem with reality, when really it’s a problem with our perception.
No more is this evident when it comes to viruses, prions, bacteria, fungus and other edge cases where our simple, intuitive definition of life fails almost completely. We simply cannot define it well enough. So, are self-replicating DNA fragments “alive”? Are organised peptide chains “alive”? Perhaps, perhaps not. The question is, in fact, meaningless. We’re going from a gradual scale of “not alive” at one end and “alive” at the other, with no sudden jump between them.
Forming amino acid chains or RNA chains in a solution has no requirement that they form a particular order. The order is refined later as life increases in complexity and begins to be acted upon by natural selection – and indeed, natural selection can refine things from random noise as a starting point. An argument against amino acids forming at all (as shown in the first three points) would be relevant to abiogenesis, but arguing that they couldn’t magically form a particular sequence is not. Besides, any chain would be a probability defying event, just as any combination of cards in a deck is a trillion-to-one-against order, yet still happens. Once that chain has formed – under the control of chemistry – that’s where we need to look at how it obtains, or at least refines, its information content.
5. The Problem of Selectivity
This is just re-wording no.4. Let’s not bother with it in too much detail. Suffice to say, the most correct bit of chemistry in it is the following quote:
Chemical selectivity concerns where components react.
Yeah, that’s about right.
Overall, this is trying to say that because a peptide chain can grow from both ends, the odds of it generating a “meaningful” sequence is small. Except, I need to just reiterate this, the concept of a meaningful sequence does not exist in the abiogenesis framework. It does for us today because we have an established system for translating DNA sequences to protein chains, and enzyme catalysts to run the show. In a hypothetical primordial soup where our main aim is simply to produce a polypeptide, the exact sequence does not matter.
Though I want to finish this with a curious observation. Throughout numbers 1, 2 and 3 (covered in part 1 of this piece), McCombs focuses on how unreactive amino acids apparently are. He goes to great lengths to say they won’t form chains. Yet here, in point 5, he is talking about the countless hundreds of isomers that should be formed. Surely, if he was under the impression the amide bonds didn’t form at all from a reaction of two amino acids, then the “problem of selectivity” shouldn’t matter at all, right? Such is the nature of a Gish Gallop – creationists are so desperate to pad out their over-bloated lists of arguments they don’t notice when their points actually start to contradict each other.
6. The Problem of Solubility
Again, an apparent Ph.D chemist seems to be displaying a sub-middle-school level understanding of polymer science. While it’s vaguely true that macromolecules have a tendency to be less water-soluble (and less soluble in general) this isn’t purely because of their length. After all – and I’m starting to sound like a broken record here – they are soluble in our cells. Protein chains and DNA chains don’t magically hit a certain length and precipitate out of our bodies and, subsequently, kill us. If solubility was a problem for abiogenesis, it would be a problem for our mere current existence. So, obviously, peptide chains and proteins definitely are water soluble.
But how does nature manage to do this? It’s simple, really, because it’s the same way synthetic chemists get around the problem; by attaching a few water soluble functional groups to the chain. But for this, I need to explain what solubility actually is.
Solubility is the ability for a substance to be broken down into just a single molecule and effectively surrounded by a liquid so that it can move freely inside it. That’s it. This is the solution phase. It’s not a particularly special thing, but it is useful for chemical reactivity because it means every molecule is spread out and open to reaction (i.e., it’s not a solid) but at the same time it’s a nice controlled environment (i.e., it’s not a gas phase). For this to happen you need sites on your molecule where the solvent can bind, so that it can be carried around in solution. In really small molecules this is comparatively trivial – a metal ion like Co(II), for instance, will just coordinate water octahedrally in its inner sovlation sphere and it will dangle around in water quite nicely. For larger macromolecules, however, we can be more specific with sites where a solvent will bind to help bring it into solution. So we need groups that are compatible with the solvent. For water, charge and polarity is important – hence why it can solubilise cobalt with a 2+ charge very easily. Individual amino acids also do this well because of the individual acidic and basic groups on them which hold a high polarity and a potential charge. As a chain increases – as McCombs points out – the number of acidic and basic sites relative to the size of the chain reduce, and eventually the solubility becomes poor. However, and this is the however that McCombs conveniently forgets to add to his list, not all amino acids are common, boring, aprotic alanine and glycine. Many have sites that will water-solubilise the protein. In fact, in protein folding these are essential as they are what drive proteins to fold up a certain way.
This interesting graphic shows the wide variety of naturally occurring amino acids. What is interesting are the wide variety of ones with charged side chains or uncharged polar side chains. There are those words again, “polar” and “charge”, which happen to be very water soluble. Bung a few of those in your peptide chain and insolubility ceases to be a problem regardless of length. In fact it really doesn’t take many of these groups to solubilise a chain, and that’s a fact abused by polymer chemists and catalytic chemists to get their stuff to be water soluble without much trouble.
And again, I’m going to leave it there and come on to 7 and 8 later, they seem to change track to a different set of chemical principles.