Wednesday, April 24, 2013

What Darwin Didn't Know- Ch 1 -The Scope of Challenges - Part 5: The Problem of Intermediates - Pt 4


Book Cover: What Darwin Didn't Know
I dove into Geoffrey Simmons' "What Darwin Didn't Know" (2004), to evaluate an anti-evolution book.

I'm maintaining an index of my responses here.

Today's Chapter - 1: The Scope of Challenges - Part 5:  The Problem of Intermediates - Pt 4

Ugh - there's so much wrong with this section that I'm having to take it sentence-by-sentence.

Release the babies!
Ape babies pass through the birth canal with their faces looking up, whereas most human babies face downward. How did the birth of a child swing around 180 degrees without any intermediate stages?
Alright, I think we've identified yet another misconception Simmons has about evolutionary theory (I could write a book).

Not all changes are going to have intermediate stages. When we're talking about initial conditions, such as how a particular organ is oriented initially, the modification of a single bit on the gene might be the difference between a binary "up" and "down". It's not that the orientation literally "moves" or "swings around" from generation to generation. Evolution doesn't need to adhere to Newton's laws of motion.

Now, I'll point out that initial conditions are much more happenstance when it comes to fertilized eggs implanting on the uterine wall, and that humans babies, for instance, do actually rotate as they grow.

Toothpicks entering pipes with flowing water, where the toothpicks start at different initial angles, and get regulated by physics to either point down the pipe or up the pipe.
Consider this - the orientation of the baby, as it escapes from its prison, may be more a question of physics than anything else.

Consider my handy diagram on the right (which I originally made to address a misconception I was having about his argument, but I find it's still useful with this one).

Even if the initial orientation of the object is random, the physical characteristics of the canal/womb may force it to be one orientation or another. It may not be possible for the baby to face sideways, for instance, under normal circumstances.

I think Simmons may be missing some information on human births, as well, although he is a medical doctors, so you'd think he'd know (BUT HE DOESN'T WANT YOU TO FIND OUT!!11!).

Frankly, I don't know a whole lot about the nuances of human birth, let alone ape births, however, a cursory investigation reveals some interesting tidbits (link to site about fetal positions). According to that article/slideshow, the babies will actually assume a wide variety of different orientations. Here's the interesting part - doctors will often manually adjust/rotate the fetus, in order to establish a more ideal orientation.

So the question is, when Simmons says "most human babies face downward", is that before or after we artificially intervene? Maybe the minority that face up were ones where doctors were not present?

Further, Simmons has actually cherry-picked the scenario. Actually, no, I'll give him the benefit of the doubt here. Maybe he just doesn't realize that our most recent divergence from the other primates was the chimpanzee, and not the other great apes. If he had chosen our closest evolutionary cousins (chimps), this argument would have backfired on him.

Just link chimps don't have tails either (like us), they also often give birth in the same fashion as humans (backward-facing) (link to Scientific American article). Of course, this realization comes 7 years after Simmon's book was published.

One might not have realized the problem, since the colloquial understanding is that we "evolved from apes". He ended up, whether purposely or not, choosing the compare humans to a more distant relative that'll have more significant differences, rather than a closer one, where the example would actually demonstrate common ancestry.

Pissing into the wind again.

I'll acknowledge, however, that the data on chimpanzees only pushes the question back another step - at what point did the statistics flip before chimps, and why? It's a good question, and should be investigated, if it isn't already.


As I've pointed out many times, this idea that there's a spot in evolution that we don't know, does nothing to support nor refute the theory. No progress can be made either way until the mystery is solved. Nor does the mere existence of a mystery invalidate the other positively-supporting evidence. What we have here is a question - nothing more, nothing less. A blank spot on a map of Texas, we're working on, doesn't invalidate the non-blank areas.

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