So, and hear me out guys, it's totally possible. What if the island is on the back of a giant sleeping turtle. You see, the real reason they had to push the button every 108 minutes is because the button is a "snooze" button attached to an elaborate alarm system set to wake up the turtle. Hencefore every 108 minutes Desmond has to hit the snooze button or else the great beast will awaken and reak havoc on the world.
hahaha jk, obviously. Thought it was funny :D