How does Buddhism reconcile evolution with reincarnation? If everyone in Tibet or Earth even for instance quit reproducing then how could a Lama reincarnate when his reincarnation depends on the freewill of the people who are reproducing?
It's important to keep in mind the true pupose of a reincarnated Teacher: "As long as sentient being remain, may I too remain and dispel the miseries of the world". If there was no one left, then the teacher's job would've been completed and there would be no further need to come back to this world. From a bigger cosmos perspective, there're uncountable other places for sentient existence, so if our planet will no longer be habitable to sentient beings in the future, a great teacher will just simply move on to other places to dispel the miseries of those "other worlds".