When I think about interactions between organisms and each other (waggle dance anyone?) and organisms and the environment, I'm often struck by the beauty of what I see. It may be partly due to the illusion of perfection that it is hard for people to wrap their minds around the idea of evolution. Ecosystems seem so planned out, and everything seems to have its place. And what about the organisms themselves? How does such a complex body plan come about so perfectly without design?
The huge problem is that we're not perfect, and neither is any other organism. Dawkins gives many examples of how the seemingly perfect often isn't so perfect. One of the examples he gives is the eye. (Sorry Jenette...) The quote above by the German scientist Helmholtz is something to think about. In reference to our eyes, Helmholtz also says " If an optician wanted to sell me an instrument with all these defects, I should think myself quite justified in blaming his carelessness in the strongest terms, and giving him back his instrument." If you believe in a god, you're not believing that god is some blundering being who makes tons of mistakes and eventually gets them right by working around past problems. I think it's safe to say that most people who believe in a god believe that that god is perfect. Which is fine except if God was the maker of the earth in six days. Because in that case, Helmholtz would be referring to giving our eyes back to god because he messed up repeatedly. I don't think that that rules out a god at all, it just backs up evolution. I think you can have a strong understanding of science and still be religious to a point. We don't know where everything came from, and no one knows how or why everything happened.
So back to problems with the eye: the photocells that pick up light line the back of the eye (the retina) and face away from the light source. The data from the light has to go back to the retina, be picked up by photocells facing a different direction, and then once they do that, nerves have to bring the data back to the brain through the blind spot. It's extremely inefficient and yet we see so well, considering all that.
Dawkins also talks about the laryngeal nerve. And in us and other mammals, it branches and detours when it has no reason to do so. There is space for it to go directly to its destination, so why doesn't it? Instead, one branch goes straight to the larynx and the other stretches down to one of the arteries coming from the heart, loops around it, and then goes right back to the larynx. This is because this artery is going around something that isn't there anymore, and although I'm a little confused about the details, the difference between this and a similar nerve in fish is that the fish's nerve has to actually go around organs which we don't have, to reach the gills. It's even worse in an animal like a giraffe. In adult giraffes, the laryngeal nerve can stretch up to fifteen feet longer than necessary! So our anatomy is based upon fish anatomy.
These detours wouldn't make any sense without evolution. It's costly energy- wise to take the longest route to a destination. It seems like what we have are variations and changes from an ancestor, because
natural selection doesn't make things perfect, it just allows variation which is neutral or beneficial to be passed on more easily. So it can change what's already there, but it can't construct a whole other nerve going directly to our larynx from scratch.
4 comments:
Hahaha, waggle dance... anyway, I don't feel so bad now being legally blind without corrective lenses. Are there organisms that can see other waves of light far beyond the spectrum we can? Out of curiosity, do you know what the farthest range of the light spectrum any organism can see?
Your post really proves that evolution isn't exactly goal oriented in terms on constructing a perfect organism, which I like because usually I always hear examples of how evolution seems to be so positive and extremely efficient. I like the point you made between God and perfection, which is true because I don't think many people would bother making the connection between these inefficient designs and God. The description of the laryngeal and its design really just seems to show that things are not just spontaneously created, they are modifications of previous designs.
I wish more people would take the time to consider this. I think you're on point when you say evolution is challenged by the thoughts people have that everything is too perfect to not have design. Nothing in this world is perfect, and we all have our faults. That's why we're constantly changing, and of course, that's why there's evolution in the first place. There's so much evidence that backs up the idea of common ancestery, just like that example of the laryngeal nerve. Similarities like this are definitely not coincidences, and even if they were, that'd disprove the idea of life having a perfect design anyway. With all this mounting evidence that just keeps accumulating throughout the years, hopefully in the near future we'll be able to see science more accepted with religion. People don't have to agree with the concept, but if there's a lot of evidence and the idea is very well possible, people shouldn't call it out as untrue and discredit it.
Ben, this is a bit...eclectic, but the beginning part might answer your question: http://theoatmeal.com/comics/mantis_shrimp
I think the most frustrating part of the whole theological/scientific debate is the fact that no matter how hard we argue it, there will never be an answer. Theologists can argue based on beliefs, therefore they can combat anything a scientist says with a nonscientific rebuttal. And no matter how much scientific evidence there is, there's no way to definitively prove that God doesn't exist, especially when the definitions of what/who God even is can vary widely. As James Randi once said, you can't prove a negative.
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