> Some 45,000 years ago, a tiny group of people — fewer than 1,000, all told — wandered the icy northern fringes of Europe.
Is it not possible that:
Some 45,000 years ago, a tiny group of people — fewer than 1,000, all told — wandered from sunny Australia into China, eventually reaching Africa and Europe?
No. The genomes tell a pretty clear story. Should your hypothesis be correct, you would find haplogroups in the 45kya group descended from the 60kya austronesian group - but you do not. Rather, you find a most recent common ancestor before the 60kya group left Africa. As to why Africa - this is where ancestral hominids and the earliest known sapiens specimens have been found. While we have found cousins elsewhere, the evidence all points towards sapiens having emerged in Africa and spread elsewhere in successive waves.
When the hypothesis first appeared it was somewhat shocking to science, as the leading theory was some sort of parallel emergence of the races - but this was not grounded in the evidence being found in Africa at the time, and genetic evidence has since cemented this not as hypothesis, but well-established theory.
Africa is a static large site of habitation where the disappearance of 99% of evidence would still leave easily findable evidence. In GP’s scenario the habitation would be transient. Not really comparable.
I mean the fictional assumption is that it was a single group that wandered thousands of miles across continents; it was many generations that would settle somewhere, with subsequent generations migrating and spreading slowly, leaving behind traces like gravesites and settlements and the like; combine that with accurate dating and you can in fact tell the direction of travel.
> Some 45,000 years ago, a tiny group of people — fewer than 1,000, all told — wandered the icy northern fringes of Europe.
Is it not possible that:
Some 45,000 years ago, a tiny group of people — fewer than 1,000, all told — wandered from sunny Australia into China, eventually reaching Africa and Europe?
It is impossible to tell the direction of travel.