What kind of boats did these migrants have at their disposal 50,000 years ago? Do these archeologists have any clue what kind of boats/water craft these folks could have constructed?
In another thread, concerning the migration of people to Japan, the archeologists in the parent article denoted a drop in sea levels, thus allowing the flow of migrants to Japan.
Not to step too harshly into the realm of historical speculation, but with the massive glaciation that occurred in the millennium past, and the subsequent drop in sea levels, wouldn't the migration to the Australian continent and surrounding isles be more easily explained as with the Japanese migration, i.e., walking/wading to the new lands?
Thor Heyerdahl constructed a raft, the Kon Tiki from South American reeds and vines to prove trans-Pacific voyages were possible.
Bamboo makes an even better flotation device with its many closed chambers and is still used in rafts in SE Asia today.
Bamboo forest in Japan.
It's trivial primitive technology using vines to bind a simple raft together. Not at all hard to imagine.
I think you are both right and wrong. I think there was a land bridge for the most part, But the reality of the Wallace line species phenomenon is real and had to be hopped by water.
And that meant a huge new land called Sunda made up of the joined major Indonesian islands—Sumatra, Borneo, Java, Sulawesi—but it didn't make land all the way to Australia. New Guinea, Australia and Tasmania were all joined together in another massive land named Sahul.
There was still a water gap between these two, as seen here:
Australia has been isolated on all sides by water throughout human times. So, no. Flores Island has produced 800,000 year old artifacts, and has similarly been isolated from the mainland throughout human times. It's not that surprising that, in a world with NO ROADS, humans have been quite comfortable moving themselves great distances by water for a really, really long time.