A publication of the Archaeological Institute of America
It has proven no easy task to resolve the archaeology of the earliest Americans. The Clovis-first model held that they crossed the Bering Land Bridge from Siberia at the very end of the Pleistocene, then cooled their heels in Alaska until about 12,000 B.P., when an "ice-free" corridor opened between the North American glaciers, creating a route south. Over the years, however, it became apparent that parts of the Clovis-first model didn't fit. Most troublesome of all was that sites started popping up throughout the hemisphere that looked as though they were pre-Clovis in age. At first, those claims were easy to dismiss: artifacts proved to be naturally flaked stones or bones, geological contexts suspiciously mixed, or dating flawed.
The site of Monte Verde, Chile, excavated from 1977 to 1985 and subsequently analyzed by author Dillehay and an interdisciplinary team of nearly 80 scholars, was a different story. Monte Verde is in a remote, cool, temperate area, where beside a creek about 12,500 B.P. a hunting and gathering band lived in a long, elliptical tent roofed with hides. Though only a thousand years older than Clovis, Monte Verde is so far from the Bering Strait that the ancestors of the Monte Verdeans must have crossed from Siberia well before 12,500 B.P. in order for their descendants to make it there on time. The ice-free corridor between the Canadian glaciers traces a route along the edge of Rocky Mountains that would have been closed from about 20,000 to 13,000 B.P. A Pacific coast route stayed open longer into the glacial period and reopened sooner but still would have presented formidable obstacles, especially at full glacial times (ca. 20,000-16,000 B.P.).
At the moment, Monte Verde and Clovis do not appear similar archaeologically, raising the possibility they are not traces of the same migratory pulse--Clovis perhaps arriving later, as the traditional model had it, following glacial retreat. Human geneticists are today examining variability among modern Native Americans, primarily using single-locus markers like mitochondrial DNA and markers on the Y chromosome, looking to resolve the number of migrations.
Monte Verde presents us with new questions: who were the first Americans, when and how did they get here, and how did they relate to one another and to contemporary populations. The search for answers continues.
David J. Meltzer is a professor of anthropology at Southern Methodist University, and Tom D. Dillehay is a professor of anthropology at the University of Kentucky.