Friday, November 19, 2010

The Watchmaker Allegory Turned On Its Head

ERV summarizes that our genomes our loaded with fossil viruses. Not only does the vast majority of our genome not do anything useful (around 97% of it in fact), a lot of it is leftover "broken" parasite code! In point of fact there have even been a few lateral transfer events over the eons, where somehow DNA gets into the genome through non-canonical mechanisms (for us, that means without sex.) Forget about the Neanderthal DNA you're carrying if you're not African - for crying out loud, we all of us have moth DNA from such an event far in the past.

The members of the various creationist lobbying groups have found the existence of ERVs unpleasant, for fairly obvious reasons. If our genomes were software, the coder would have been fired a long time ago! This doesn't say much for the intelligence of the designer. The most famous intelligent design allegory is the found watch, proving the existence of a designer. There are big problems with this analogy. First, the designer and the process by which this object got made is obvious. You can go take a tour of the watch-making factory! No one has ever showed me a universe-and-consciousness-making factory, despite how keen to see it I would be.

But the fact that we now have evidence of exactly how watches and walruses get made should be enough to stop worrying about this. And indeed, when we don't have a process for how an apparently ordered thing got to be that way, we should and do ascribe free will and deliberate design to its creator, as happened in the mid-20th century with the discovery of pulsars. When astronomers first discovered stars littering the galaxy that were "beeping" at an exact interval of around once a second, a few of them were quite anxious. They had no way, based on the physics of the day, to understand how such things could come to be on their own, so one explanation was that these were put there as beacons by alien intelligences. Eventually we figured out we were dealing with a dumb physical process - collapsing stars speeding up in their rotation to conserve angular momentum, like a skater spinning faster when she pulls her arms in. (Phew.) And tell you what: if, in the future, a Mars lander finds an object that keeps time and for which we can't figure out a natural process of development, then one explanation has to be that it was designed by an intelligent agent. (But then it would be Martians, not Allah. Or whoever the Discovery Institute thinks it was.)

Second, the allegory is really about order vs. disorder, and the process of how order comes into being. The watch is implicitly taken as an ordered object in contrast to a background of disordered nature; but then in the implied conclusion, suddenly we're told that nature is ordered after all, and needs to be explained like the watch. Which one is it Paley? And why aren't we called on to explain the origins of why Mt. Shasta is shaped a certain way or the tree on top of the hill next to your house leans to the left - or does that not require a divine explanation? If not, why not? If Paley had found a watch that ticked, but was stuffed with 97% bits of paper and dirt and rocks that not only were unnecessary to its function but made it slow down or break sometimes, would he have said "what a wonderful design; clearly a brilliant watchmaker created this?" No, he would have said "what moron put this together?" And each new ERV found in the genome is another bit of sand in the gears.

Bottom line: why do we care about this? What will be the effect if tomorrow everyone or no one believes in evolution? Evolution and origins are interesting but we have the business of morality and suffering to consider, and the discussion should always serve that, even if indirectly.

*As an aside, you might wonder how inefficient it is, energy-wise, to have to carry around all this non-coding DNA. I know I always have and I'm not quite satisfied with the answers I've received, so if you're reading this and you know, please comment! It's true that prokaryotes don't have junk DNA or introns, and the just-so story (so far as I know) is that they can't afford it since they're far more dependent on fecundity than the towering, ubercomplicated Rube Goldberg contraptions that some of we multicellular types have become since we parted ways. A biologist once made the point that the energy you spend cleaning your house outstrips by orders of magnitude the energy you spend reproducing your junk DNA that day. I'd still like to see for this reason if single celled eukaryotes have less junk DNA than multicellular ones, and it also seems like there is a greater potential for copying mistakes with global consequences proportional to genome size.

1 comment:

TGP said...

If there's a walrus-making factory, we should take a tour. I am up for either an assembly line of walrus meat with a big shock to the heart at the end or a large pile of sweaty walrus love. As long as it ends with crates of walruses loaded into trucks for distribution and a few shined up ones on rotating platforms in the showroom.