What was the original purpose of the appendix?

Question: What was the original purpose of the appendix?

Asked by christiancox to Fiona, Joanna, William on 24 Jun 2010 in Categories: General.
- Joanna Brooks answered on 24 Jun 2010:
  
  Hello again! The appendix is about 8cm to 10cm on average (quite long if you think about it) and was thought to be used for digesting things like leaves back when humans were still evolving from early primates (apes). But humans don’t use the appendix anymore so it is like an ‘ancient’ part of human anatomy.
- Fiona Randall answered on 24 Jun 2010:
  
  They think it is the shrunken version of an intestine that our ancestors needed that we don’t, maybe something monkeys needed to digest leaves.
- William Davies answered on 24 Jun 2010:
  
  It’s a evolutionary relic left over from our mammalian ancestors – primitive rodents used to have a thing called a caecum which was full of enzymes to digest grass and the stuff they ate. as we evolved from them, we started a diet of meat instead, didn’t need all those enzymes or anywhere to digest the grass, so the appendix remained but didn’t have a function. after many more years of evolution we’ll probably lose it altogether

Question: What was the original purpose of the appendix?