What is the Physiological Function of Toothache?

[Dekan]

Obviously pain can sometimes serve a useful purpose.

Eg, you put your finger onto a very hot object. The heat causes your finger to feel pain. This pain lets you know, that physiological damage is being caused to your finger. To avert this damage, you take physiological action: you move your finger away.

 

So the pain served a purpose: it prompted you to take the necessary action.

 

But suppose you get toothache. Your tooth aches, and the torment of the pain goes on and on.

 

What physiological action is this tooth-pain supposed to prompt you to do?

 

Wrench the tooth out with your bare fingers? Visit a dentist? But there weren't any dentists for 99% of human evolutionary history.

 

During this history, what did our ancestors do - try to bash the aching tooth out with a flint hand-axe?

 

That would likely be ineffectual, and just cause more distress. Probably there wasn't anything much could be done.

 

What then is the physiological function of a pain such as toothache, that you can't do anything about?

[zapatos]

The pain in the tooth also prompts you to take the appropriate action.

 

The pains are not specific to the actions we should take, and they cannot 'know' if there is something that can be done or not. The burning finger pain did not say 'move your hand', it just said something was wrong and you then made the decision to move your hand.

 

Likewise, the pain in your tooth is just saying something is wrong, and you have to decide what to do; bash out the tooth, go to the dentist, or spit out the red hot coal that was stuck to your freshly grilled mastodon and is now burning your tooth.

[SMF]

Dekan, this is an interesting question. It also suggests further questions regarding all pain. For example what is the function of cancer pain, or any internal pain from an evolutionary perspective? An external injury, such as a foot or hand, the pain is obviously telling you to leave it alone so it can heal. Disturbing a wound makes infection much more likely, and to make an infection worse. This is also true regarding internal injuries, but why cancer or a tooth ache. Actually, maybe there is a dentist in the house that could tell us if avoiding chewing on a painful tooth makes any difference in the progression of the disease.

 

For what it is worth, my opinion is that there is no evolutionary significance to pain that you can do nothing about or that is caused by something that will kill you no matter what you do. If some trait or factor doesn't affect the ability to pass on ones genes, there is no selection for or against it. SM

[Marat]

I think zapatos is on the right track. The entire nervous system evolved as a whole for the evolutionary purpose of making people withdraw from harmful effects on themselves, to pick away infected swellings, to pull out barbs, etc., but the nervous system cannot know whether it is giving its typically useful signals in useful situations, like taking a finger away from a hot stove or pulling out a thorn, or non-useful situations, like tooth-ache and cancer pain.