I think there's a trend in archaeology of us realizing we've been underestimating the past. The Polynesians were capable of voyaging across the Pacific to South America, and another Austronesian group made it all the way to Madagascar. This was pretty controversial until Kon-Tiki; even now, Polynesian-South American contact isn't fully accepted. (IIRC, we weren't sure how the Polynesians even found so many islands, u…
The Torres Strait is full of small islands bridging the 150km gap between PNG and Australia. Not only that, but much like the Strait of Dover or the Bering Sea it was most certainly a land bridge until the holocene, and it remains extremely shallow.