What is the new widely accepted theory for how humans first arrived in the Americas, if not for the traditional Bering Land Bridge hypothesis?
ianburrell•1h ago
The new theory is that they came along the coast. Clovis culture arrived 13-16,000 years ago through corridor in ice sheets. But earlier sites, including these footprints, suggest that people arrived another way. These footprints are 21-23,000 years ago. I don't think there is any evidence how they got there, but the coast is plausible explanation.
tempestn•1h ago
When you say "the coast", do you mean travelling south down the Pacific coast after crossing the Bering land bridge?
There is genetic evidence linking these very old inhabitants to Pacific Islanders of that time and there were more islands at that time because of lower sea levels.
AlotOfReading•2m ago
It's really confusing to use the term pacific islanders here. The farthest humans had reached was the Solomon Islands, what we call "near Oceania". The places people think of when they say "Pacific Islands", namely Remote Oceania (Melanesia), Micronesia, and Polynesia were all uninhabited. Those early Papuans weren't especially closely related to the founding populations of the Americas, though they're closer than you might expect from the geographic distance because of the serial founder effect.
chneu•12m ago
There is also evidence that pacific Islanders made at least two trips to the Americas using rafts.
I believe generic testing shows pacific Islander and early Asian DNA mixing.
Stefan Milo on YouTube has a few videos looking into different theories.
advisedwang•1h ago
My lay understanding is that the theory is that these earlier humans crossed the Bering land bridge but that they didn't proceed through a inland ice-free corridor (as there was none then). They likely traversed the pacific coast, which was not at the same position it is today and so would leave no evidence.
I have also seen discussion of sea arrivals, but they are much more hypothetical.
Also worth noting as the earlier arrival doesn't rule out the later ice-free corridor traversal as having also happens - it just means it wasn't the first people to arrive in the Americas.
o11c•1h ago
It's not that different. There's just dispute over when exactly between 30kya and 11kya people first crossed.
__cxa_throw•2h ago
ianburrell•1h ago
tempestn•1h ago
Edit: ah, the earlier discussion covers this: https://news.ycombinator.com/item?id=44319585
m0llusk•1h ago
AlotOfReading•2m ago
chneu•12m ago
I believe generic testing shows pacific Islander and early Asian DNA mixing.
Stefan Milo on YouTube has a few videos looking into different theories.
advisedwang•1h ago
I have also seen discussion of sea arrivals, but they are much more hypothetical.
Also worth noting as the earlier arrival doesn't rule out the later ice-free corridor traversal as having also happens - it just means it wasn't the first people to arrive in the Americas.
o11c•1h ago