The most common Lost question I have heard: Why are there Polar Bears on the island. Of course everyone saw the Pilot or the commercials about the Pilot and they all are confused or put off by the fact that there are Polar Bears on a tropical island.
I personally couldn’t care less, something like Polar Bears on a tropical island just cause interesting stories, do we really have to know why they are there.
But apparently we do so I’ll tell you why I think they are there.
We know the island has moved in the past, hence Ben’s familiarity with that power of the island (see this page for more about the island moving). I believe that at one point the island was at the North Pole, or close to it. Hence Penny building a monitoring station up there. Also it could explain the magnetic properties of the island. Since the island was up in the Arctic Circle, it became a home to Polar Bears, when the island unexpectedly moved, so did the Polar Bears. Voila.
for more read the Original Post.