Re: Every generation
The Tasmanian aboriginals were arguably, no longer viable as a population long before the colonial power arrived on the island, if nothing else by virtue of lack genetic diversity (ca. 2000 individuals). Their apparently highly dysfunctional social order more or less guaranteed a mass exodus of the remaining females to the arms of eagerly awaiting freed convicts and other settlers who themselves were looking for appropriate partners who were very, very thin on the ground at the time. Birth rate decline amongst the indigenous along with susceptibility to western diseases and a penchant for robbing the sugar and flour larders of the settlers pretty much sealed their fate.
Lyndall Ryan was wrong, and almost anything you might think you know about the Australian Aborginal history, and the Tasmanian Aboriginal population in general, post colonialisation is almost certainly wrong.
You clearly have no idea how big the planet is either. Humans CHOOSE to live close together because it affords us, via our social systems, advantages that the more primitive societal models do not. This, despite having to deal with the attendant, often very fatal, crowd diseases that cannot flourish without, well, crowds. In any case, the earth is provably not crowded and it unlikely to be so any time soon. The question of whether humans are overextending the ability of the earth's resources to support our species is a different question.
I now return you to your regular programming in progress ...