While the various fields studying the underlying 'facts' do take a scientific approach, workers in those fields would be the first to admit that they are hugely ignorant, and will likely always remain so. Too, Moonbear is right (as she so often is); run the tape again and the songs will be different, no one can say how.
However, there do appear to be some common themes:
- the influences etc that underlie the development of writing, complex societies, money-based economies, etc are much the same everywhere in the world
- all major landmasses with Homo sap. have shown consistent trends re transitions from hunter-gatherer modes of food sourcing, through to permanent agricultural settlements and the rise of 'states'
- the major differences are in the timing, largely due to a combination of resources (esp domesticatable plants and animals; and suitable land), and cultural exchange (including trade, and exogamy)
- so, left alone, even the Australians would likely eventually have developed agriculture, states, writing, mechanised warfare, etc.
Unfortunately (?), Adam is correct in saying that there's little in history - both recorded and otherwise - to suggest that human groups do anything other than conquer neighbours (and enslave them, or slaughter them, except for the young women) or go on crash development to resist slaughter or enslavement (or flee, if they can), up to when they have been centralised states. Once states are established, the other outcome has been subjegation - extract tribute through a local puppet or figurehead. In this, the US overthrow of Saddam is consistent (and the US's non-intervention in, say, Liberia, also; too few resources).