I was just thinking about all the questions that are still left and havent been solved. One of them, the polar bears, was bothering me. And i came up with a solution. remember how Ben went down to turn the wheel and move the island when it was in "danger"? it was cold down there, yes. And assuming from what we've seen with ben and locke, when you turn that wheel, it transports somewhere. When we first see Charlotte, she's an anthropologist, discovering the skeleton of a polar bear in the middle of the desert. (the polar bear also had a DI collar) My theory is that when the DI first began, they had the polar bears trained to turn the wheel on command. Instead of sacrificing humans to turn it and get transported. It makes sense right?? And remember how Sawyer was in those cages stepping on those buttons to get a cracker? Well thats possibly how the DI got the polar bears smarter.