There are several theories on the relationship between the island and the two stories Pi tells at the end of the book. Basically, it boils down to whether you choose to believe the first or the second story. Regardless which version you choose to believe, Pi survived, and the two stories are the same except for the allegory and symbolism.
One belief is that Pi felt it necessary to create the first story in order for him to be able to cope with the actual, horrific events of the second story. Richard Parker is Pi's darker side, the side he must allow to rise to the surface in order to survive. The tiger jumps from the boat and is never seen again, just as Pi's darker side returns deep within Pi, never to surface again. Richard Parker may also have been a way for Pi to deal with his loneliness. Each animal is symbolic of the human characters in the lifeboat, and the island with algae is a metaphor for the raft made from oars and life jackets. In the beginning, the island is a safe haven from the dangers in the lifeboat, providing Pi with food and shelter. It also symbolizes Pi's despair toward the end of the book, and the carnivorous vegetation stands for his pessimistic belief he will ever be rescued. Staying on the island would mean Pi is giving up, deciding to end his life on a man-eating island. Later, Pi realizes he must return to the boat to face his fears and hold onto whatever hope he can that he'll survive.
None ,the carnivorous algea defy conventional knowledge and would have to be explained differently in order to fit into the more humanly acceptable second story.On page 299 ,Mr. Okamoto is pressing Pi to logically justify the"two blind people in two separate lifeboats meeting up in the Pacific'' and the Meerkat or mongoose bones.They want the second story without animals and without improbable meetings and carnivorous islands.But Pi shows them the real truth , page 317, Mr.Okamoto: ''Yes.The story with animals is the better story.'',Pi Patel: "'Thank you. And so it goes with God.'' I believe that this is the central message of the novel ,that the faith and hope and love that belief in God or gods facilites in the human soul enriches their lives, makes the improbable possible,teaches acceptance of the strange ,miraculous and anamalistic and definatly makes for a better story.
This is by Ponygirl119's Mom, Whitney, who homeschools me, Anne AKA Ponygirl119.