Wednesday, January 12, 2011

The Memetic Equivalent of the Recurrent Laryngeal Nerve

A post over at Epiphenom got me thinking about the old idea of religion as a product of natural meme selection, and how that metaphor could be viewed from different angles.

The recurrent laryngeal nerve is a nerve that provides sensation and motor control to the larynx. It is called "recurrent" because it takes this weird backwards-looping path through the neck, when there is no apparent reason -- without the evolutionary background, that is -- why it shouldn't just descend straight from where it branches off from the vagus nerve down into the larynx.

The reason becomes obvious when you examine the morphological transitions from fish to land animals and eventually to mammals. A common trait in nearly all modern animals is a segmented body plan, which seems to have evolved very long ago. You can often figure out how the segments in one group of animals map to the segments in another group -- adding a segment here, replicating one here, transforming this one for an entirely different purpose... And if you do this morphological comparison with fish vs. mammals, it becomes pretty clear what happened with the recurrent laryngeal nerve. It's morphological equivalent in fish followed a perfectly sensible path, and as the body plan was rearranged, it just got pushed further and further out of the way.

And why didn't natural selection ever fix it? As an engineer, I put it as, "Because evolution by natural selection is an algorithm that is highly susceptible to local maxima." Perhaps a simpler way of saying it is that by the time the laryngeal nerve had developed a routing problem, the type of mutation required to fix it was far too complicated to occur in a single generation -- and a mutant who only got "halfway there" would not be likely to have a functioning laryngeal nerve!

Is the modern concept of prayer the memetic equivalent of the recurrent laryngeal nerve?

First, an obligatory caveat: Whenever we talk about memetic evolution, we must remember that we are just drawing an analogy. Genetic evolution only works "right" because it is digital (i.e. each base pair has a discrete value -- each base is either A, C, T, or G, and you cannot have a base that is 75% A and 25% T!). This turns out to be really important in making the math work out, because it enables traits to be inherited as a discrete unit. As an example, if your mother has green eyes and your father has brown eyes, probably you will get one or the other, but you will not get a blend. If genes were not digital, and if sexual reproduction produced a blend rather than a discrete sampling, evolution via natural selection would not work.

Memes are sometimes digital, as when the meme is a particular phrase or perhaps a particular translation of a book. In those cases, evolutionary analysis tends to work quite well (nearly identical techniques are applied by both evolutionary cladists as well as those examining the "mutations" over time of copied manuscripts). But memes are often not digital -- as, I would argue, in the case of religions themselves, even if the texts are digital -- and in those cases it is not clear to what extent evolutionary theory really works. So when we talk about a meme like religion "evolving", we might just be blowing smoke.

With that out of the way, let's assume it's valid to talk about religion "evolving" by natural memetic selection. When we look at the evidence for biological evolution, there are certain fingerprints of natural selection that we expect to see, and -- as the Intelligent Design losers are always pointing out -- if we didn't see these fingerprints, it would be pretty disturbing to current theory. These fingerprints are things like the recurrent laryngeal nerve. That's an extreme example, but the point is that we should see animals "designed" in a way that betrays a compromise modification of an earlier design, rather than an optimal "clean sheet" design.

So do we see those fingerprints on religion? Yes we do. And I think that the concept of prayer, at least as it relates to most modern religions, is a real doozy. I haven't posted much about it, but I've discussed with my wife the bizarre contradiction among virtually all modern religions between belief in a God that is omnipotent and omniscient and benevolent and has a perfect "plan" vs. the habit of prayer. If God's plan is perfect, why are you bothering her with suggestions?

This logical clunker is a damn good candidate for the Abrahamic equivalent of a recurrent laryngeal nerve. If you look at the Judaic God, omnipotence and omniscience (but not necessarily benevolence or possession of a perfect "plan") are important adaptive traits, which the Torah hammers home again and again in pointing out that if you mess with God, he will mess with you -- and how! (visited upon the third and fourth generations, etc.) The same is true of Yahweh's predecessors and rough contemporaries, but I mostly want to look at the Abrahamic lineage here. (On a side note, another distinctive "adaptation" of Judaism is the idea of a chosen people. This trait seems to be a big winner early on, but it also seems to be directly in contradiction with that whole "evangelical zeal" thing, which turns out to be hugely adaptive, for obvious reasons.)

For an omnipotent -- but not necessarily benevolent -- God, prayer makes perfect sense. "Please sir, if you could just find it in your heart to not kill us all today, that would be great." She can do whatever she wants to you, but if you ask nicely, there is still room for convincing.

Now, I am not an expert on the development of early Christianity, but at some point there seems to have been a definite shift towards the idea of a benevolent God. I suppose one could argue that this shift had already begun with Judaism. As megalomaniacal and erratic as the God of the Torah is, his capriciousness does not rise quite to the level of the Greek Gods, for example. Yahweh might kill every living thing on Earth except for one family just because he thought some of them were dicks, but he wouldn't turn into a bull and go rape some people on a whim. Christianity pushed things even further in this direction: God is perfect and fair and benevolent (and by the way, if that seems to be a laughable impossibility in the face of the evidence, it's Your Fault for not understanding his "mysterious ways").

The adapative benefit of this is obvious as well. The Greeks had less incentive to devote themselves to their gods, because who knows when Poseidon will just randomly trick your wife into cheating on you. The Jews have more incentive, because God at least claimed to have specific enumerable rules that one could follow if you wanted to stay on his good side. And the Christians had more incentive still, because not only was God supposedly perfectly fair and just, but he also really wants to help you out. He's on your team. Work with him. Be his buddy.

But now what of prayer? The Torah speaks of an antecedent religion that used human sacrifice, which mutated to animal sacrifice, which finally mutated away from even that at some point in the development of Christianity. The methods of supplication kept getting pushed in a more humane direction, in a direction where god was less of an "insane bully" and more of a "protective father". Just like the laryngeal nerve, the method of placating one's god kept shifting to accommodate newer adaptations. And just like the laryngeal nerve, by the time this gradual shifting becomes a problem, it's too late to do anything about it.

Surely many thinkers over the centuries must have realized the inanity of pleading with an omniscient being who already has a "perfect" inalterable plan. But what are you going to do? "The Pope has determined that prayer doesn't make any damn sense any more, so although Mass will still include communion, confession, etc., there will be no more prayers." No, of course not. Prayer was such a fixture of the religion by that point, it couldn't be changed. Even if prayer makes as much sense in modern interpretations of Christianity as it does to get from the vagus nerve to the larynx by looping underneath the thorax.

There are more obvious "fingerprints" of the evolution of religion, of course -- basically, anything that can be traced back to syncretism, such as celebrating the alleged birth of Jesus (which, if one takes the Bible literally, can be inferred to have probably occurred in September, or maybe in the spring, but most certainly not in winter!) over the same time frame as a pagan winter festival, and adopting numerous traditions from said festival. But those syncretic fingerprints are neutral. There is no horrible logical contradiction in choosing an arbitrary date for celebrations, and plenty of practical value in lining it up to coincide with other religions' festivals.

But I think that prayer in the face of omniscience is a really interesting one, because it really demonstrably is a suboptimal solution. I'm not the only one to realize that it doesn't make any sense. One of the most visible and frequently practiced aspects of your religion is a bald logical contradiction. Even with most homo sapiens being rather poor critical thinkers, that still can't be good for business. And yet, it ain't gonna change, because to fix it without doing damage would require a radical memetic reorganization, one that is unlikely to occur naturally.

This is important because it really drives home the fact that even if religion became so dominant because it evolved to confer certain social benefits, that tells us nothing. Just as with the laryngeal nerve -- which, to be fair, works just fine -- with human foresight we might just put together a system that's far superior and far more sensible.

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