This has already been an exciting year in archeaology with the find of the lost city of Etzanoa and the 11,000 year old city of Gobekli Tepe recording an ancient comet strike. Now we have this. We have all been told that humans came across the Bearing Straight or the land bridge around 10,000 to 15,000 years ago from Asia to the Americas. A flood of new research has cast doubts on that narrative as bones and sites seem to indicate humans may have been here as early as 20,000 years ago. Now, a new brilliant new study in Nature indicates that humans were in California 130,000 years ago. How did they figure this out?
Starting with the Mastodon
The researchers began by analyzing the remains of a Mastodon which was found near San Diego. The Mastodon was your run of the mill Mastodon finding except that the tusks had distinctive cut marks on them which seemed highly artificial to the researchers. After matching the cut marks to a anvils, hammers and stone tools which were found nearby, researchers knew that they had found something interesting. According to iflscience.com:
State-of-the-art uranium dating techniques revealed without question that these tusks were 131,000 years old, as were the marks on them. No known carnivore or geological process could have made such precise scratches on them, and the site itself had remained undisturbed by erosional processes since it appeared.
While the study is definitely groundbreaking, it raises a number of important questions.
Who Were These People?
Well, as the New York Times said about the study, they were almost certainly not modern humans:
If humans actually were in North America over 100,000 years earlier, they may not be related to any living group of people. Modern humans probably did not expand out of Africa until 50,000 to 80,000 years ago, recent genetic studies have shown.
Some have speculated that the people could have been Neanderthals, Denisovans or perhaps a species of humans which we know nothing about. The Neanderthal hypothesis is interesting because it could help answer some interesting genetic anomalies in the historical record. Neanderthals are not known to have existed outside of Europe and the Middle East. However, all modern humans except Africans, have some percentage of Neanderthal DNA. Europeans tend to have more than Asians but Native Americans have even more, which does not make a lot of sense historically since they originated from Asia.
The Denisovans, the diminutive species which was primarily found to exist in Asia could also make sense. Their remains have been found throughout Asia and have even been found in New Zealand, indicating they traveled widely.
Interestingly, Denisovan DNA is also present in Neanderthals. According to Wikipedia:
A comparison with the genome of a Neanderthal from the same cave revealed significant local interbreeding with local Neanderthal DNA representing 17% of the Denisovan genome, while evidence was also detected of interbreeding with an as yet unidentified ancient human lineage. Similar analysis of a toe bone discovered in 2011 is underway, while analysis of DNA from two teeth found in layers different from the finger bone revealed an unexpected degree of mtDNA divergence among Denisovans.
The reason we do not know anything about the people in question is that their remains were not found. The only things that were found were the Mastodon remains as well as the tools nearby. Some scientists are challenging the quality of the study but others are applauding its thoroughness. We will have to stay tuned to find out more.