The island is Atlantis.

The Others are the last survivors of this lost and ancient civilisation (and perhaps also the children of the scientists of the dahrma). The statue in the last episode of season 2 could represent those strange people. We know that the Egyptians (in the real world) could have had relations with the Atlantan people so that can explain the hieroglyphs in the hatch. The Atlantis myth includes a great scientific knowledge of this civilisation. In the real world, we have never found Atlantis: this could explain the fact that they can not escape from the island and that no one have found them.I think the Dharma and Alvar Hanso have found the Atlantis island and also the great power of this ancient civilisation. The Others use that power which can explain the black smoke monster that can scan people. The Others have mental powers due to the knowledge and the gentic code (DNA) of the Atlantan civilisation.

I also think that this would be a good explanation - it would also explain the healing properties of the island.