Nature recently came out with two blockbuster papers establishing a better chronology on the settlement of the New World by humans. More precisely, the papers seem to push the likely date back by over 15,000 years. The figure above is from one of the papers. It shows human-derived artifacts from sites that date to 25,000 years BP and even 32,000 years BP.
I have recorded a podcast with the first author of one of the papers (she is second on the other). The podcast should post later today. Nevertheless, talking to the author I am more than 50% convinced that humans were present in the New World 32,000 years ago, and 90% convinced they were here 25,000 years ago. This is well before what is needed and expected from the standard “Beringian standstill” model.
The Beringian standstill alludes to the fact that the proto-Amerindians, a mix of Paleo-Siberian (ANE) and diverged East Asian, may have occupied Beringia for thousands of years before finally pushing southward ~15,000 years ago. The sites in the database of these papers show that a huge explosion of human occupation characterized North America during this period. But these were not the first humans.
I believe these new results likely open the possibility for a resolution of the mystery of why some groups in the Amazon seem to have “Australasian” genetic affinities. The result is robust. But it was hard to resolve with the Beringian standstill. The new chronology offers up an opportunity. Clearly the earlier populations before 20,000 years ago may have been the ancestors of the “Australasians” that are still hinted at in the Amazonians. I believe that these early people were members of what I have termed Clade-2 East Eurasians. This clade was dominant in South, Southeast Asia, Tibet, and present in coastal East Asia (Japan), during the Pleistocene. It has closer affinities to Oceanians than East Asians to the north.
If the first humans in the New World arrived as coastal fringe dwellers, it is clearly plausible that populations from Japan and points south could simply have done a circum-Pacific arc. We’ve seen lots of mass replacements in the ancient DNA, and the WST-Clovis groups seem to have been very numerous. Weak to no genetic signature of Clade-2 New World peoples is not surprising. There is no evidence of Oase Aurignacians in modern Europeans.