My theory is based on a lot of information provided only in the last few episodes, but the as the episodes have progressed the theory seems more plausible. However, this is only a partial theory and may only fit into a larger explanation of many of the mysteries on the island. The argument is that all of the survivors of the plane crash actually died and were cloned on the island not including the Others, Desmond, or Rosseau. Now the way this was actually done I'm not sure about, but there are facts both supporting and discrediting this theory. Facts supporting this theory include Locke's ability to walk again and Jin's fertility which could be accomplished if they were cloned. Also the the man with the eyepatch who was "killed" when Locke threw him into the supersonic fence was seen alive a few episodes later after possibly being cloned. Naomi states the survivors were all found to be dead in their plane if they were dead is it possible that DNA samples were taken before they left Australia and were used to clone them on the island and the actual people were killed in the plane ending any search for survivors. Locke's father also said he was in a wreck and woke up on the island it is possible that he actually died and was cloned and brought to the island. Juliet was also knocked out and woke up at the island it is possible that she too was cloned. The only problems I see with this theory is that the Others saw the plane crash; however, they did not see where the plane crashed so it is possible that Dharma or Ben set up a faked plane crash on the island and released clones without the Others knowledge. Ben has been known to have vast capabilities as was shone when he provided Juliet with footage of her sister so this is plausible. Claire was also pregnant with a baby which could be difficult to explain; however, the story has been setup so that such an explanation is possible. The final problem I see is the fact that the survivors all have their previous memories, but a science fiction respones to this could provided like the one in "The Sixth Day". If anyone has anything they could add to this theory or any arguments against it I would love to be able to make my theory more credible.