I have a feeling that the answers to a lot of the big questions on Lost are going to be really simply once it all gets unspooled. Doling it out bit by bit as the creators have done over the years just makes it SEEM complicated. I am almost never a theory-maker–I prefer to let the story do its thing, but to prove my simple-is-the-answer point, I wrote this–
clears throat:
The Others, or Natives, are descendants of the Four-Toed People. The 4-Toes are members of an ancient, advanced, Atlantis-like civilization that either created or discovered the Island. Eventually, through attrition or disaster, their civilization went into decline, leaving only the Others on the Island to tend to it and protect it.
The Smoke Monster, possibly built by the 4-Toes long ago, aided them in their duty as long as they obeyed the Island. Though the knowledge of its exact technology was lost to them, they still understood its basic function and have permission to call on it, but only in times of great need. Otherwise, they are its mercy.
Then the Black Rock crashed on the Island. Humans from the outside world discovered the Island’s amazing properties and coveted them. The Natives fought them off, but the captain of the Black Rock, Magnus Hanso, escaped to the normal world with a diary and his memories of this extraordinary place.
Centuries later, Hanso’s descendant Alvar used his company the Hanso Foundation, along with other powerful businessmen, to form the Dharma Initiative, in hopes of using modern technology to find the Island. They succeeded, and the Initiative immediately set up shop on the Island and began experimenting. They met with resistance from the Natives, which they dubbed Hostiles, and a long conflict ensued. Eventually, the Others won when Benjamin Linus defected to their side and helped eradicate the Dharma Initiative in a single act of mass murder. Charles Widmore, prominent among the Initiative, felt personally robbed of the Island by Ben and began a long war against him to win the Island back.
Then Oceanic Flight 815 crashed on the Island. Little known to them, the Island has been grooming the survivors to take the place of the Others their whole lives. While the Others have descended from enlightened to violent and amoral, the Survivors of 815 are already broken and messed-up people. The Island plans to put them all through redemptive tests that in the end will make them worthy to replace its current caretakers.
(My only hole is Jacob. I figure he is either the spirit of a 4-Toe with a special connection to the Island, or maybe a manifestation of the original force that originally created the Island, currently enslaved by the Others and trying to get Locke to help him. Those could both be a little far out.)
[/theory]
I’m probably not as spot on as Lonely Toaster, but the basic idea that it’s an Island where miracles happen, being fought over by various people over the ages, is pretty much what it boils down to. Everything else is just details.