Expert: John Shea - 5/23/2007

Question
Some people on my current forum claim that dental health was almost perfect during the Palaeolithic, and that it only declined in the Neolithic. However, I read a  New Scientist article which claimed that human dental health was already badly affected by the invention of cooking, during the Palaeolithic(see below):-

http://tinyurl.com/3w78h

Which one do you think  is right?

Cheers

Answer
Gerald,
The think to keep in mind is that our teeth are the most labile (flexible during growth) tissues in our body.  Early hominin diets have probably been highly variable in time and space, as well as over life history, since very early stages in human evolution.  Part of this is due to the use of tools as, bascially, artificial teeth. What this means is that there a persistent kind of "arms race" between evolved patterns of human dentition and prevailing selective pressures relating to diet.  The only way you'd get stable selection for a particular form of dentition was if there was strong pressure towards only one kind of food morphology.
Cooking is a problem because it softens up food that would normally be fibrous, and easy to clear from the teeth.  This is a novel evolutionary problem with which we, as a species, are still contending.
Paleolithic people didn't often have the kind of advanced dental decay problems we do (caries, etc.) mainly because they lived very short lives.
Cheers
John Shea