[...] we should expect the world’s memeplex to evolve in a manner maximally incompatible with Xhosa survival.
Forgive me if this should be obvious, but why would it be maximally incompatible, rather than merely indifferent? Just because their brains aren’t necessary for reproduction doesn’t mean that there’s any evolutionary incentive to actively kill them, either.
Also, for a belief originating in a region dominated by the Xhosa, Xhosa brains are pretty necessary, since they make up a good majority of potential hosts. It’d be different if some random person from, say, Venezuela received the prophecy.
Forgive me if this should be obvious, but why would it be maximally incompatible, rather than merely indifferent? Just because their brains aren’t necessary for reproduction doesn’t mean that there’s any evolutionary incentive to actively kill them, either.
Also, for a belief originating in a region dominated by the Xhosa, Xhosa brains are pretty necessary, since they make up a good majority of potential hosts. It’d be different if some random person from, say, Venezuela received the prophecy.