From the rulebook: "Sorcerers can conquer a Region by substituting one of your opponent's Active tokens with one of your own taken from the storage tray".
In this case, is the lost tribe token consider an opponent?
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Sign up to join this communityLost tribe tokens are neither an active race nor under the control of an opponent, so they clearly can't be the target of the sorcerors' ability.
The Sorcerer's power can not be used on the Lost Tribe tokens.
Source: http://boardgamegeek.com/thread/391216/what-we-know-so-far-clarification-of-rules