Fleeced!

I cannot claim credit for this putting of 2 and 2 together - heard it somewhere else - but it makes perfect sense.
Season one, we see a polar bear on the island. Total frackin' weirdness, makes no sense.
In subsequent seasons, we've seen what appear to be cages for the polar bears and then the skeleton of a polar bear with Dharma collar in some desert.
Significance? I think we now know.
The room with the donkey wheel was Arctic cold, right. That, plus the bear skeleton, leads to a pretty solid conclusion that Dharma was - and this sounds kinda stupid as I write it - was training polar bears to work the wheel to move the island, so that a human wouldn't be zapped to Tunisia. Instead a bear would take the fall.
So this one mystery - the polar bears - points to everything great and stupid about the show. Great = since season one, they've been working to this point wiht tantalizing clues along the way, none of which we could fathom until now. Stupid = polar bears trained to work a wormhole-manipulating wheel in a frigid undeground cavern on a mysterious island? Even the cheesiest Roger Moore Bond flick never went that doofy.
Dammit, it's a long wait to next season.