Origins debate: Evolution

Structure générale d'un acide aminé.

I find that when a debate spans more than one generation, it often becomes difficult to follow – especially for newcomers. The Origins debate (often unthinkingly called “Creation/Evolution debate”) definitely qualifies. But despite their entertainment value, misunderstandings from both sides (including yours) don’t help anyone get anywhere. And that defies the point of a debate, right, Mr/Ms Militant ________ist?

So the Microscope, being of a biological inclination, will do what it always tries to do: help us see better. Whether it suceeds is up to the viewers to decide. And I think its fair to start with an overview of evolution theory. Why? Well, no Darwin, no debate.

By the way, I won’t bother with references etc. This is meant to be (relatively) quick and painless.

So, this is how current evolution theory goes:

Life begins with abiogenesis – rudimentary biomolecules (primitive amino acids or primitive genetic material) arise from inorganic, “non-living” molecules. Cement’s been poured in the foundations. Now, strictly speaking, this is not “evolution” yet since we can’t speak of “natural selection” without genes. Big mistake, made by many. As far as evolution goes, how life began is a bit beyond its purview.

Back to the pond: Due to external/environmental factors and what can only be described as chance, these proto-biomolecules combine in different ways, giving rise to complexity. But remember: mere complexity doesn’t ensure survival (if anything, quite the opposite). Still, we’re all here, which means that something must’ve clicked. But exactly how that could have happened is still a red-hot item of debate.

So, now we have something like an amino acid – or a nucleotide. Building blocks that can combine a bit more easily under the current conditions. And they do – the rise of peptides or genetic material. More complex macromolecules are here. And some of them “survive” while the others perish – the usual. This process then repeats itself, randomly or semi-randomly, meaning that it’s probably fuelled/energised by external factors (temperature, pH, energy zaps, the presence or absence of other elements/molecules), which also act as a selective force, allowing some complexity to “survive” and “killing” off the rest.

Remember: in mainstream evolution theory, nothing is born because it’s objectively functional. It just happens to be in the right place at the right time.

Given enough time, complexity increases and is “favoured” by the selective conditions as compared to other complexity that might have arisen. As molecular complexity increases, information also increases. Entropy wants to break down everything to the simplest forms. For a macromolecule (peptide, RNA, polysaccharide – take your pick) to come about – let alone go against the grain and “survive” – it has to rely on more than mere chance. Like any system, its structure contains information, and if that information is going to increase as complexity increases (we’re obviously not just peptides anymore), it needs a way to pass on from “generation to generation” efficiently and relatively stably.

Enter the gene. Somewhere down the line, a coding system has developed (will develop?  Who knows?). Simple molecules, the nucleotides, can string three together to “represent” what has become the building block of complex organisms, an amino acid. This new method is relatively more accurate than just trying to put amino acids together to make proteins. It’s a template. A design of some sort that is not as vulnerable to chance as waiting for something as complex as a protein to just arise out of primeval goo.

The gene is the bee’s knees. Compared to anything else out there, it’s simple, efficient and ensures the relatively accurate passage of information through time. But it’s not perfect. To build even a basic cell, it needs a fairly complex molecular machinery; something to “translate” three nucleotides into an amino acid. What all this means is that the gene system is prone to alterations. It’ll make mistakes every now and then, and we call those mistakes, mutations.

Mutations are interesting. Most of them stop everything dead in its tracks. But every now and then, they cause just enough change to survive into the next generation. Give it enough time and mutations accumulate. Some accumulations make it, so don’t. But give it enough time, and you just might end up with a whole new trait. And maybe that new trait actually increases the survival chances of the particular organism over all its other friends, because they didn’t get the upgrade.

Of course, all this depends on the conditions out there. Where and when you’re alive. It’s all relative. Black colour won’t help you hide if you live in a white, snowy tundra. Better colour perception is not as good as improved hearing if you’re nocturnal. And so forth.

And that’s evolution in a nutshell (a coconut shell, actually): Mutations, chance, and survival conditions – a process we call natural selection. All you really need is a genepool, resources and time.

You get the idea – and really, you didn’t need me to tell you. It’s not like there’s a scarcity of information on evolution out there. But as I have often expressed my own doubts about the mainstream Origins dogma in this blog, I thought I’d demonstrate that I actually understand it first – and hopefully help others digest it.

After all, if you don’t evolve, you’ll get eaten.

To be continued...

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