Dateline: 08/10/97
Thomas Jefferson, arguably the first scientific investigator of the past, wrote that question in his field notes as he was excavating a mound at Monticello. When and how humans arrived in the far flung parts of the world--that is, far flung from our Homo sapiens sapiens origins in Africa--is part of the essential problem that interests most archaeologists and paleontologists, and all people for that matter. After all, creation myths are in part attempts to answer the question "Where did we come from?" Origin myths are ancient oral history, and are by nature wrapped in metaphor and mystery; they often contradict one another and although there is certainly cultural truth in them, they are ultimately unsatisfying to the scientific curiosity.
This spring, unshakable evidence from the Paleo-Indian site of Monte Verde in far southern South America rewrote our understanding of the origins and date of arrival of humans in the so-called New World. Located in a peat bog 500 miles south of Santiago, Chile, Monte Verde, a small village of 20-30 people living in 12 huts, was better preserved than any other Paleo-Indian site in the Americas. Food, in the form of extinct llama, shellfish, a variety of vegetables and nuts, and most astoundingly, a chunk of mastodon meat, was recovered at the site. A single footprint, that of a small child, was preserved near a hearth. And, based on a suite of radiocarbon dates from bone and charcoal from the hearths, the site is 1,300 years older than any other known archaeological site in the Americas.
The history of how American archaeologists have come to believe what they do about the origins of humans in the Western hemisphere explains in part why the latest news is so exciting.
As you might imagine, the earliest years of scientific archaeology were exciting times. The general consensus in the early decades of the 20th century was that humans had not been in the Americas more than 5,000 years. But in the late twenties, evidence of the coexistence of humans with now-extinct animals such as mastodon and extinct species of horse and bison, began to surface. Archaeologists realized that humans must have lived in the Americas before 10,000 years ago.
In 1949, Willard Libby and his associates invented the radiocarbon dating technique, and for the next 45 years or so, we did think we knew when humans reached the North American continent. All of the sites we found with clear, unequivocal evidence of human activity located south of the Bering Strait land bridge date no earlier than about 11,200 years before the present. In archaeological opinion, the most likely path of entrance was across the Bering Strait and over land down into what is now the United States and southward. For most of the time between 100,000 and 10,000 BP, Canada was covered with a thick shield of ice, which didn't begin to melt back until 13,000 BP. Sites dated to 11,200 years before the present are dotted all over the map in North America below the ice shield; 2,800 years to get to the continental US from the Bering Strait seemed completely reasonable.
There were a few, a very few sites that predated 11,200 BP, but each one was in some way suspect. Until Monte Verde. At an absolutely rock-solid date of 12,500 BP, it is 1,300 years older than any site found in North America. And it is 10,000 miles south of the Bering Strait land bridge. That means that if the route into the Americas was overland across Canada, the inhabitants of Monte Verde were descended from people who crossed 10,000 miles in 500 years. That works out to twenty miles a year, if you make a beeline to Chile. On foot. In completely unmapped, foreign territory.
You can imagine how excited we are: archaeologists love a good puzzle.
Excavator Tom Dillehay of the University of Kentucky at Lexington has published a complete report of the site of Monte Verde, Chile, which is available at Amazon.com.
See ya next week!
