One aspect of basic biology that is almost invariably neglected when discussing the possibility of the continued existence of cryptids like Homo floresiensis is

One aspect of basic biology that is almost invariably neglected when discussing the possibility of the continued existence of cryptids like Homo floresiensis is that there must be an isolated breeding population. Plate tectonics puts a limit on the size and depth of caves. So how do you hide a breeding population? The short answer: it is impossible.