There probably a split in those people, with one group going across the Siberian strait and the other group going to Australia by way of Indonesia.
Depends on how Australasia is defined.
Quick search online for definition of “Australasia” - “Australasia, a region of Oceania, comprises Australia, New Zealand, the island of New Guinea, and neighbouring islands in the Pacific Ocean.”
Australasia is in essence Australia and New Zealand, little Islands in-between, PNG included.
Some confuse the term Australasia for Asia-Pacific; not the same.
Aside from European settlers last 200 or so yrs in Australia & NZ, there are mainly Polynesians, Melanesian, and Caucasians in the mentioned boundaries of Australasia.
I was told on FR a few months ago that Indigenous Australians (Aborigines) are actually Caucasians. There is a lot of mixed genes since 15000 yrs ago.
Anyway, a child of an Australian Aborigine and an European today often easily looks much more like a European, complexion, eyes and hair colour.
However, in Australia today, Australian Aborigines and “Islanders” have their own official ‘race’ category.
Just sayin... in my experience with South Americans of indigenous heritage it’s really hard to see an genetic resemblance between the South Americans and the aboriginal Australians...I mean, we are talking about a radical swing from sweet and hot to...NOT...LOL!!!
What about the Zanzibarbarians?