Diatribune

(The following constitutes the last part of a short three-part series on evolution)

So far, I have endeavored to disassemble two of the favorite (non)arguments of fundamentalists and denialists against the reality of the process of evolution - namely, A) that humans have remained essentially unchanged since Creation; and B) that the science underlying evolution is wrong/invalid.

Mind you - notwithstanding that I so endeavored by using a tongue-in-cheek-with-a-wink approach, the facts provided in these two previous entries of mine remain soundly grounded in reality and scientific accuracy (taking into account that I have to vulgarize the science at the same time).

It is therefore with the same approach that I intend today to disassemble a third favorite myth of the fundamentalists and denialists typically used in their (intellectual sloth-driven and ignorance-based) attempt at "disproving" evolution: there is no randomness and no natural selection in life.

Now, I've already discussed one recent example of random mutations followed by selection so as to provide an evolutionary advantage in humans - therefore, I will not dwell again on this.

Rather, I will focus on randomness. To whit (one zany example among so many - emphasis mine):

"Randomness and Divine Agency - In their article “Random Worms: Evidence of Random and Nonrandom Processes in the Chromosomal Structure of Archaea, Bacteria and Eukaryotes” (PSCF 55, no. 3 [September 2003]: 175–84), Glenn Morton and Gordon Simonsmake made a valuable contribution to the design debate. However, a couple of comments might be in order. First, I am not sure they have correctly applied biblical references to the Urim and Thrummim or to casting lots. In those examples, the point is not that God used randomness, the point is that when instruments of chance were employed to seek the divine will, the outcome was not random at all. As the authors themselves say, “God pre-determined the result”. A predetermined result is not an expression of chance. That makes the application of those examples to processes in nature problematic. If “humans are not able to distinguish between the appearance of chance and the actuality of chance”, and if “randomness is something that cannot be proven”, then it is not clear why “Christian apologists need to incorporate chance and randomness into their world views”. After all, we can neither distinguish it nor prove it, and it does not exist from God’s point of view.

Second, the authors claim that “Dembski’s model is inadequate to the task he intends”. But if

Yes, yes, yes. We know the saying: "God does not play dice" (sayeth Albert Einstein - unfortunately, he had no inkling about DNA, genes and what I'm about to talk about below). So "of course", we can't distinguish or prove randomness because such a thing does not exists.

Very well, then - check this one out ...

Like every life-form on this planet of ours who reproduces sexually, males and females of the homo sapiens sapiens species produce gametes - spermatozoids (millions of'em at a time) for men and an ovum (or egg) for women.

For both sexes, we start off with precursor cells. Now, these cells, like the rest of our cells, contain 46 chromosomes - 23 pairs of each human chromosome, except that half came from Mommy and the other half came from Daddy. The whole idea behind precursor cells having to undergo gametogenesis (i.e. produce gametes) is to produce gametes with only a single copy of each 23 chromosomes so that they may recombine (or fuse) with one of their gender counterparts - then, we have fertilization (i.e. restoration of our "full" genotype of 46 chromosomes) and the fertilized embryo can develop from then on.

Here's where randomness is observable directly and proven:

First (trying to simplify things as much as possible here), precursor cells make one round of normal cell division, giving two daughter cells with 46 chromosomes each. Then, the two daughter cells undergo reductive division, each generating two daughter cells in turn but with 23 chromosomes each (only one copy of each human chromosome). That leaves us with a total of 4 gametes per precursor cell, right? For men, yes - multiplied by hundreds of precursor cells to start with and hence the mass production of spermatozoids. However, how come women normally produce only 1 ovum per ovulation cycle? That's because one precursor cell is used at a time and 3 of the potential 4 gametes produced are killed off randomly.

That's one roll of the die right there.

Second, for both women and men, the 23 "Mommy" and 23 "Daddy" chromosome copies can swap DNA ("crossing-over") with each other during the reductive cell division process needed to produce gametes (and yes - you could say that the parental units are unknowingly still "going at it" years and years after they made you - or that this is actually molecular self-sex - but I digress). This process ensures increased individuality/diversity in the progenies-to-be ... in other words, this allows for the off-chance that the children will have one or more improved attributes compared to their parents (better immune system, more brainy, more athletic, etc.). Of course, you can also end up with decreased attributes (weaker immune system, less brainy, less athletic, etc.). Interestingly, whether a pair of Mommy-Daddy chromosomes does a cross-over or not, and which specific pair (or pairs) gets to actually do it, is in good part determined randomly.

There's another roll of the die for ya (come to think of it - that's a roll of two dice).

And last (but not least): out of the millions of male spermatozoids racing to the single female ovum, only one gets to fertilize it and "win the day".

Talk about rolling the dice here!

Now here's the clincher: all of these (ahem) random things constitute altogether one of the very bases of the evolutionary process.

So, in conclusion, here's a suggestion for you folks the next time you meet a fundamentalist/denialist: instead of going (again) into a tiresome argument with them about the reality of evolution (especially since their nonarguments are tediously inane - one example addressed here), simply invite them for a fun game of Yahtzee.

It will not only be so much more enjoyable, but you'll be proving the point at the same time.

And remember: evolution is not belief, faith, philosophy, ideology or quackery - it is science.

No more, no less.

(Cross-posted from Another Point of View)
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