pauraque_bk | fucking ow

Current Mood: enraged

Entry tags:

egypt,
health

fucking ow

Still working the toothache remedies, and also got the dentist to score me some vicodin. I wonder why tooth pain gets so blindingly intense... what's the evolutionary value there? In the absence of modern dentistry wouldn't it just be a source of disabling pain for tons of the population? All the time in egyptology you hear about mummies with severely decayed and abcessed teeth (partly because of the environment; sand would get in their food and cause dental wear and tear), which boggles my mind. I'd rather have them all pulled out than that, though the prospect of having damaged teeth extracted without anesthesia is a bit daunting.

Maybe proximity to the face/brain/"self" makes it seem worse than it is? I don't know. God fucking damn it though.

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Actually, it's probably evolutionary advantageous for pain in your lower extremities to hurt less than pain in your skull. You know, if you get banged in the head you're pretty fucked, but if you twist your ankle, with a little adrenaline you still have a pretty good chance of survival.

If evolution really gave a shit, we'd shed teeth like sharks, though.

Maybe I missed a day in school, but I'm not sure I understand why SEVERE pain is necessary. Pain alerts you to a problem -- good! Pain itself preventing you from doing anything about the problem... seems bad?

TBH I always thought that was a pretty dumb explanation for pain. Surely we feel severe pain because having your body getting torn up is going to feel bad as a consequence of having a sense of touch, not solely because it's some sort of brain message about how bad it is? This is why I think we can't feel our organs very well, and our brains not at all: because you don't use your pancreas to feel a rock.

Mm, true, there are a lot of severe medical problems that cause no pain (at least not until it's far too late). Though it seems sensible to have pain to alert you to, say, bending your finger back too far, or touching fire -- that's an actual helpful warning that stops you from accidental injury. Then again, that sort of warning pain isn't conscious, I think it stops at the spinal cord or something.

Maybe I'll read a book about it when I'm not in a haze of drugs and ow.

If evolution really gave a shit, we'd shed teeth like sharks, though.

Actually, not just sharks do it, most non-mammals with teeth do. Sharks are more famous for it because they also have row upon row of teeth!. Mammals are specifically evolved not to do this.

Because nothing but mammals have complex, multipurpose teeth the way we do, and they're supposed to mesh very tightly. The only you've got a chance to get them to fit together like that is to have a very specific planned growth sequence. If they grew in whenever, they'd all be different sizes.

The meshing in turn is because our metabolism run so high, we need very efficient eating. The planned (and delayed) growth of teeth, in turn, is probably the reason milk evolved.

I could go on for a while about my theoretical frameworks this all fits into, but I've already just gone on for a while :p

p.s. I got no ideas on the pain, though.

Edited 2009-04-04 19:23 (UTC)

Anyway, I think your theory is good except for the connection between metabolism and teeth. Birds have a very high metabolism and they don't have teeth at all. You could say that 'well, birds fly', but it seems increasingly likely that they inherited the metabolism from dinosaurs, who had teeth that shed. (And of course, we would also be ignoring all the birds who went back to ground and kept their metabolism without their teeth.)

Aw man, LJ ate my original comment

:( I hate when that happens.

If birds evolved from dinosaurs that had high metabolisms and mammal-like complex teeth and then lost them and kept them lost even when they stopped flying (and we know birds have the ability to start growing teeth again, so it is actually significant that they didn't); then that would be, as you say, a significant problem with the theory that mammals' teeth are important to their metabolisms.

However, that is not the case. The dinosaurs birds evolved from, theropods, did not have complex, interlocking teeth, they had the standard rows of spikes common to vertebrates (as opposed to ornithopods, which had complex, differentiated teeth like mammals).

So the question is not, "how could birds have lost their teeth if teeth are crucial to a mammal's high metabolism". It is "how did theropods, avian and non, solve the problem of high metabolism that mammals require complex teeth to solve". This is a much less problematic question, since it suggests theropods evolved a different solution (there are always other solutions), rather than that birds had a good solution and lost it.

I suppose. I still think there must be a much better reason for us to have non-replicable teeth than metabolism since there obviously IS a different solution. (Caveat: of course, evolution doesn't always pick the most efficient system - it works with what it's got.)

I tend to think that the reason we have non-replaceable teeth is because cutting-and-grinding action is just SO GOOD that evolution does not care about losing a certain percentage of gene carriers to tooth decay. It strikes me as inefficient, but what the hell. If evolution was a tech person, I think she'd try to feed me a line about it being feature not a bug.

I do want to correct the bit about the Ornithopods: they had complex, differentiated teeth that were also replaceable. The rate of replacement of each tooth in the tooth battery is used to estimate the population of all the hadrosaurs. Aaaand the reason that matters is because now it seems like they had feathers too (http://www.livescience.com/animals/090318-feathered-ornithischian.html). Which is pretty recent and also, mind-blowing.

Maybe you knew that and I'm just being an ass. My apologies if so.

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