I think a more natural diet will probaly imrpove health. However, there are more than one natural diet. Some tribes ate mostly meat while some ate very little meat. Besides this fact, there is little evidence to point to their longevity. The evidence might point out to the fact that they were healthy while alive but not neccesarily longevity.

It seems to me that, the protective of nature of some non evolutionary items outweigh the negative side effects. This is only the case when the foods are eaten as naturally as possible.

I might be wrong - i think i'll probaly re-read that big paleo website (beyondveg.com)and the one i linked above and then make another reply.

I really think though that using fossil evidence and paleo remains is a terrible way to decide what diet is healthiest. It sounds very in exact. Even tho food surveys, that are used to give us an understanding into the eating habits of particular groups of people, are flawed, i still think they are better and more scientific evidence than food remains. It's just my opinion and its open to debate...