> If an indigenous people is the first to settle
Not what it means.
Not what it means.
This is true in Australia and the US as well, the Aboriginals and Native Americans just came several thousand years before the next waves of settlement.
I'm certainly not claiming that 'indigenous' means their ancestors literally sprouted from that ground.
There are some other relevant characteristics, which make the definition a bit fuzzy.
The biggest one is that they need to have retained some identifiable aspects of their culture in the face of subsequent settlement.
But to a first approximation, first to settle - or at least being among the first to settle - is the primary basis for determining indigenousness.