[jbssm]

Many people think that but archeological evidence says the contrary. Caries only started showing up in humans 3000-4000 years ago when we started doing agriculture and eating cereals.

Before that we practically didn't had caries (just like wild animals also don't).

Throughout human history humans would have the full set of teeth in the vast majority of cases, until we started settling and switched from hunter-gatherer to agricultural society (which is a very recent time in human species development).