the design of teeth...

[joko]

i was just thinking how all the little crevices and bumps are where decay begins and are the hardest bits to keep clean... so why have they evolved that way?
i know some ridges are useful for chewing but i can see that all the little tiny ones help that much - and not enough to outweigh the inevitable decay they promote...

we all know how before people used toothbrushes, teeth were generally in a terrible state and mostly rotted and fell out.

so why has this design not adapted and basically smoothed them out...?
i would think the cliche cartoon version of a tooth would actually be the ideal...smooth with 4 'corner' bumps...

is there any reason why they have stayed so crinkly...?

just a thought

thanks

[RATTER15]

Maybe they have not finished evolving yet?

[RATTER15]

Also if we ate a completely "natural" diet they probably would not need to be cleaned and we wouldn't have these problems.

[LazyGun]

I think you have to remember Joko that modern man is quite a lot removed from what we first were.Advances in technology, medicine, agriculture and everything have progressed at a staggeringly fast rate.

From an evolutionary point of view, a species is a success if the overall design allows the species to pass on its genes for the next generation. And given an estimated species population of around 7 billion and counting, humanity certainly does that.

Modern humanity, thanks to advances in, well everything really, now lives far longer than the original design might have envisioned. We also eat much, much more processed food and sugar than the original design specs specified, and sugar especially is a major contributor to tooth decay.

Finally - We are not designed to an idealised, perfect template.An examination of the design of the eye, or the prostate gland, or the meandering, looping path of the carotid artery will tell you that As a species, we are a compromise between differing, competing systems. For example, it may be that sharp vision was, from an evolutionary perspective, a more valuable asset and so resources were devoted to developing vision at the expense of teeth.

[rov1100]

Tooth decay in certain parts of Africa are relatively unknown. It is the Western diet that causes problems and with all the lectures by celebrities and politicians alike this could change our way of eating.

[gen2]

LazyGun gave the key quote earlier.
"From an evolutionary point of view, a species is a success if the overall design allows the species to pass on its genes to the next generation."

Tooth decay would start to have a deleterious effect on the health of individuals AFTER procreation so there would be no evolutionary pressures attempting to diminish tooth decay or any other affliction of the elderly.

HOWEVER, some credence has been given to a small evolutionary pressure to select against diseases of the elderly because of the added benefit of having the older generation around as part of an extended family. as such they can assist as babysitters or pass on worldly knowledge that assists that family to survive in preference to a family that have lost their older generation.

The Social Services and NHS have somewhat taken over that role to such an extent that there is no longer any evolutionary pressure to select against single-parent families, those with disabilities, those with reproductive dysfunctions etc. Evolution is defunct as far as humans are concerned until such time that financial drains on the economy cause the collapse of society as we know it and then natural selection will kick in again if there are any of us left.

[joko]

gen2...yes i have often thought that we prevent certain types of evolution by our reliance on external and unnatural things.

perhaps if we had never invented toothbrushes, our teeth would have evolved better...as it is theres no real 'need' as such ...

[HowardKennitby]

Lovely Media URL: http://www.thegoonshow.co.uk/scripts/teeth.html
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[beso]

For anything to evolve there must be selection. That means that those with the undesired traits must reproduce less than those with desirable traits. So I guess this could happen if people with bad teeth couldn't attract partners.

It would dscourage sugar in the diet too except giving someone chocolate might be a more powerful attractant than good teeth.

[RATTER15]

>>>perhaps if we had never invented toothbrushes, our teeth would have evolved better...as it is theres no real 'need' as such ... <<<<

Im not sure evolution happens quite that quickly :)

[jno]

"I guess this could happen if people with bad teeth couldn't attract partners."

I think it's really the invention of beer, rather than toothbrushes, which solved that problem.

http://www.tshirt-rev...r-Tshirts-BeautyB.jpg

[wildwood]

In terms of evolution, humans have been around for a mere flash and developed a more herbage based dental structure than the other branches of primates. It is going to take a lot more than a hundred or so generations to change our dental shapes through natural selection. Artificial teeth are now so common, even in younger people, that the selection affect will be minuscule.

[scowie]

We only suffer tooth decay because we have sugar in our diets.

Before the western world started importing sugar, peoples teeth lasted a lifetime without ever having to brush at all. This is shown in ancient burial remains. There is a clear point in history that shows this turn around. Before sugar, people died with intact teeth, after they died with many teeth missing and signs of major tooth decay.

We basically invented tooth decay some time in the Middle Ages. It is pretty difficult to avoid eating sugar today. Bread has sugar added and this is probably the biggest cause of tooth decay.

[Old_Geezer]

If the teeth lasted long enough for one generation to survive to breed and care for their offspring until they can care for themselves, that's all evolution is likely to achieve. Job done.

[theprof]

Scowie, I'm afraid your are not correct in attributing tooth decay to sugar alone.

Acidic foods also cause tooth decay. taking some examples, orange juice with a pH of around 3.8 is effectively a double-whammy for tooth decay as it's both high in sugar plus quite acidic.

Diet Cola contains virtually no sugar, yet is a known cause of tooth decay due the phophoric acid it contains giving it a pH of about 2.5.

Finally, vinegar at normal table strength has a pH of around 2.0 and is once again a known cause of tooth decay.

Yes, there has been a statistical increase in tooth decay since refined sugar became available in the Western World, but tooth decay has been demonstrated in countless skeletons of early man. This has been attributed to a diet high in acidic fruit such as oranges, pineapples etc where these fruit occur. People did not die with intact teeth as you put it.

Any dentist will tell you that the finger cannot be pointed to sugar alone.

[theprof]

As to the biggest cause of tooth decay, next time you have a prolonged appointment at your dentist, ask him or her about Kellogg's Frosties.

[Old_Geezer]

But they're great !

Read recently that apples are more destructive to your teeth than fizzy drinks are, the suggestion being that fizzy drinks are not in the vicinity of the tooth to make a lot of difference, unlike eating an apple.