Who Got Here First?

The vast majority of archaeologists agree that the first humans evolved somewhere in Africa. They don't necessarily agree where, but they do agree it was somewhere on that continent. There are practically no researchers, however, who would argue that the first humans evolved in Asia, Europe, or the Americas. This means that at some point, humans had to walk out of Africa, and then across the world.

Archaeologically speaking, this has prompted some interesting questions, like who got there first and when did this happen? It was a slow foot race across the globe, and as far as archaeologists are concerned, the first people into the Americas came across the Bering land bridge that connected Alaska and Russia when sea level was low due to glaciation roughly 14,000 years ago. The first culture to develop in North America came from these settlers, and are called the Clovis people, traditionally assumed to have existed roughly 12,000 years ago. That's what we long believed.

However, some new archaeological sites are causing people to question that assumption. Chief amongst them is the Cactus Hill site, which may force archaeologists to review their evidence on the race to North America, and reconsider who crossed the finish line first.

When there were lots of glaciers, sea level would drop and reveal the Bering land bridge

Cactus Hill

Cactus Hill is located on the Nottoway River in Virginia. Due to the changing course of the river over time, the region is covered in hills of sand that were once riverbanks. It was in one of these hills that artifact collectors in the early 1980s stumbled on some unusual finds, which were reported to a retired state archaeologist. Cactus Hill was tested by archaeologists in 1988, then formally excavated from 1993-2002.

Rivers in Virginia tend to have sandy banks, creating sand mounds like Cactus Hill

So, what did they find? Well, at first there was a pretty clear Clovis site. The Clovis people had a very distinct type of stone tool, so it was easy to recognize. There was no sign of the Clovis site having been disturbed, and yet as archaeologists kept digging below the Clovis site they found more artifacts. There was some burned charcoal, consistent with campfires where people would live, as well as a whole set of various stone tools. The strange thing was that these tools did not match the very-consistent style of the Clovis people.

Implications

Now, one of the basic assumptions in archaeology is that the stuff on the bottom is older than the stuff on top, indicating the order in which things were deposited. Since the site had not been disturbed by shovels or burrowing animals, the artifacts found several inches below the Clovis site had to be older. But how could something be older than the oldest culture in the Americas? That's the real significance of the Cactus Hill site. Researchers believe it could provide the strongest argument ever for a pre-Clovis culture, meaning that people inhabited North America much earlier than previously thought.

So, let's review the evidence. The Cactus Hill stone tools don't look like Clovis tools. This site was found below an undisturbed Clovis site. Also, the charcoal found at Cactus Hill is an organic material, so it could be carbon dated, and ending up being dated at roughly 18,000 years old. And if you recall, archaeologists have, until now, thought that people first came here around 14,000 years ago - several thousand years later.

Archaeologists look at layers of deposits as one way to determine the age of artifacts

This is not the first time that there has been evidence pointing to a pre-Clovis culture in the Americas. However, all of the other sites have issues that cause skeptics to question the dating of those artifacts.

Cactus Hill is the only place where we see a direct lineage of occupation sites. You've got a (potentially) pre-Clovis habitation site, then right above that a Clovis habitation site, and then above that other later habitation sites. It's a continual, unbroken sequence that helps verify the accuracy of the dates procured by carbon dating the charcoal. However, the mainstream archaeological community probably won't completely accept a pre-Clovis culture until a second site like this is found. We just want to be sure.