What Does The Appendix Do?

What are the implications of the loss of bacteria from the shrinkage or loss of the appendix on humanity's ability to eat older, denser plant materials?

• If the bacteria in the appendix was primarily for digesting food that was heavier in plant matter/ uncooked, etc than what we eat currently, it would imply that humans are no longer able to eat what our human ancestors ate 2 million years ago.  This has implications for natural diets, Paleo, whole grains, etc. See -

• Answer:

  I think you'd have to go far back beyond the Paleolithic to find appendixes in the humanoid line that had much of a digestive function. Even chimpanzees and other humanoid apes have only short appendixes. Some New and Old World monkeys seem to have functional appendixes, though, so the split may have happened only 130-or-so million years ago. The appendix and its human history shouldn't play any role in evaluating the Paleo diet.