The Clovis First Hypothesis

Podcast Transcript

In 1932, archaeologist Edgar B. Howard made a major discovery near the town of Clovis, New Mexico.

He found a stone spear point embedded in the rib of a woolly mammoth, which inspired what became known as the Clovis First Theory.

According to this theory, the creators of these spear points, known as the Clovis people, were the first to settle the Americas about 13,000 years ago.

Archaeologists accepted this for decades, but new discoveries have put the theory into question.

Learn more about the Clovis First hypothesis and how it is being challenged on this episode of Everything Everywhere Daily.

The Clovis First hypothesis is a theory that explains how the first humans came to the Americas. It has been a powerful narrative for decades, one that most anthropologists and archaeologists have accepted as fact.

The Clovis First hypothesis holds that the earliest human inhabitants of the Americas belonged to the Clovis culture, arriving around 13,000 years ago via the Bering land bridge and migrating south through an ice-free corridor between continental ice sheets.

From this entry point, Clovis peoples were thought to have rapidly spread across North America, bringing a distinctive fluted stone tool technology and representing the first successful peopling of the New World.

This is probably the story most of you have heard.

For the purposes of this episode, the important point is that the Clovis People were the first to enter the Americas, meaning no one came before them.

The roots of Clovis First hypothesis lie in discoveries made in the early twentieth century in the American Southwest. In the 1920s and 1930s, excavations at Blackwater Draw near the town of Clovis, New Mexico, revealed finely made stone spear points in clear association with the bones of extinct Pleistocene animals, particularly mammoths.

Radiocarbon dating, developed after World War II, placed these Clovis sites at roughly 13,200 to 12,800 years before present. At the time, no other sites in the Americas were widely accepted as being older.

Because Clovis artifacts were found across a vast area of North America, from the Great Plains to the Southeast and Southwest, archaeologists inferred a rapid and successful expansion of a single cultural tradition.

This association was crucial. It demonstrated that humans had been present in North America at the end of the last Ice Age and had hunted now extinct animals.

From these facts, other facts were assembled to create the full hypothesis.

The Bering land bridge between Asia and the Americas, was often open in prehistory, creating an ice-free corridor from Alaska to Canada and the continental U.S. It opened briefly about 13,000 years ago.

According to the Clovis First Theory, these early humans followed large prehistoric animals across the land bridge into North America and began settling along this migration route.

The theory stood unopposed for much of the 20th century and became entrenched as archaeological orthodoxy.

To be fair, there was a good reason why the theory became so entrenched. It fit the known facts, and it made a ton of sense.

Opposing theories or evidence that countered the Clovis First theory met strong resistance. Leading archaeologists swiftly challenged new theories. Critics dubbed defenders the “Clovis-First Police.”

New sites sometimes showed evidence of life predating the Clovis culture. Each claim sparked critics to discredit the findings, reinforcing the entrenched Clovis First view.

For example, human fecal matter pre-dating the Clovis Culture by 1,000 years was discovered in the Paisley Caves in Oregon.

The coprolites (fossilized feces) discovered in the cave in 2008 were met with initial challenges, though not immediate contradiction. The issues stemmed from the DNA being contaminated, the appearance of the coprolites not suggesting a human origin, or the layer they were found in at the site not corresponding to a human encampment.

Clovis-First scientists questioned everything about every site that emerged—soil quality, artifact authenticity, dating methodology, and extraction methods.

Another good example of Clovis First scepticism emerged when a Pre-Clovis site was discovered in 2006 by a team from Texas A&M along Buttermilk Creek in Salado, Texas. The site quickly became a strong pre-Clovis candidate, with thousands of tools and points found mostly in the soil layer below the Clovis period.

It was a breakthrough for pre-Clovis advocates. Other sites hinted at Pre-Clovis, but few matched Buttermilk Creek’s volume of artifacts.

Subsequent discoveries strengthened the case against Clovis First. Sites such as the Meadowcroft Rockshelter in Pennsylvania suggested a human presence earlier than 13,000 years ago.

Breakthroughs, however, met scepticism. Clovis First supporters questioned the find’s authenticity, suggesting tool mixing or criticising dating methods. Critics even attacked the soil, suggesting that soft creek-bed soil might have let artifacts sink between layers.

For many Clovis First advocates, no pre-Clovis site would ever be able to challenge their beliefs.

This scrutiny wasn’t new, as Clovis First researchers had challenged every threatening finding since the 1970s.

Yet despite repeated dismissals, the debate over pre-Clovis sites intensified with the discovery of the first major pre-Clovis site in South America, Monte Verde II in Chile, excavated by University of Pittsburgh archaeologist James Adovasio.

Few defended an alternative theory to Clovis First as strongly as Adovasio. A major figure in American Archaeology, Adovasio passionately defended Monte Verde, believing that the Clovis First theory was on its last legs.

The hearths at Monte Verde were dated to 19,000 years ago, but critics contended that the samples were contaminated by the high levels of coal-derived carbon in the region’s soil, despite the fact that there were no coal seams in the vicinity.

Adovasio eventually presented evidence even Clovis-First advocates struggled to refute: pieces of woven baskets.

The baskets appeared in multiple layers of soil. They showed distinct construction methods, and the material passed modern dating tests. Adovasio’s most notable find was a spear point that differed from Clovis-age tools.

Likewise, a spear point found at the Meadowcroft lacked the distinctive features of New Mexican tools but also showed advanced craftsmanship.

Amid debates over Clovis, another find was uncovered in Kenosha, Wisconsin.

In the 1970s, a field owned by farmer John Hebior was excavated after he found a fossil. The excavations lasted nearly 25 years, and in 1994, scientists from the University of Wisconsin-Madison and Marquette University found a complete mammoth skeleton with human butchering marks.

The bones with the marks have been radiocarbon dated to reveal the animal’s death at 14,500 years before present. This places it more than 1,000 years before the Clovis sites of New Mexico.

The Hebior site became a focal point in the Clovis-First debate. Nearby sites supported similar finds. A mammoth kill site at Mud Lake, Wisconsin, has been dated to 19,000 years ago, providing further evidence.

The greatest controversy arose at the Cerutti mastodon site near San Diego. Unlike earlier finds, it pushed boundaries not by a few thousand years, but by almost 100,000 years before a Clovis-First migration event.

As a result, the site was subjected to enormous scepticism and scrutiny. Scholars had difficulty accepting the site’s stone tools as man-made, and many argued that the damage to the bones had been caused not by humans but by later highway construction in the area.

The claims regarding the site’s date were so surprising that they have yet to gain widespread acceptance, including among pre-Clovis researchers.

The Bluefish caves in the Yukon, excavated by Canadian archaeologist Jacques Cinq-Mars, have sparked ongoing debates over pre-Clovis habitation… a process that Cinq-Mars likened to the Spanish Inquisition.

Cinq-Mars rejected Clovis-First; his site showed habitation 10,000 years before the land bridge. Despite strong evidence, Clovis-First advocates attacked his findings, leading him to lose funding for his project.

The discoveries at the Bluefish caves were centred on stone tools found at the site, alongside a wide variety of ice-age animal life, including Mammoths, Yukon horses, and giant bison.

Many of the animal remains and their bone markings were dismissed as unreliable until the discovery of a horse mandible bearing the unmistakable marks of intentional incisions.

Finally, perhaps the site that contributed the strongest evidence for a Pre-Clovis culture was Cooper’s Ferry, Idaho.

Like the sites in Wisconsin and Pennsylvania, Cooper’s Ferry represented a departure from the typical sites found in the West or in Canada, providing further geographic diversity to pre-Clovis claims.

Cooper’s Ferry is located downriver along the Columbia River valley, intersecting with the Snake River and on to the Salmon River.

The 300-mile migration from the Pacific coast to this site appears to have been intentional. The Cooper’s Ferry site contained stone tools of a completely different technology from those at the Clovis-age sites.

The tools and charcoal hearths located at Cooper’s Ferry dated back 16,000 years. To many, the 2019 discoveries in Idaho represented the final nail in the Clovis-First coffin.

San Diego State archaeologist Todd Braje, who reviewed the work done at the site, proclaimed: “The Clovis-First model is no longer viable.”

The conclusions of the Cooper’s Ferry site were clear to many: while Clovis peoples were an important migratory pattern in history, they were not the first peoples to have arrived in the Americas.

To many, the debate was closed. There had simply been too many sites that contradicted the Clovis-First conclusions. The ability of Clovis-First defenders to discredit the growing number of sites was becoming untenable.

There is still a shrinking number of archaeologists who have stuck to the Clovis First playbook and continue to try to contradict pre-Clovis findings.

Their opinions are unlikely to change.

However, this all brings up another question: if the Clovis First hypothesis isn’t true, then was the Bering land bridge the primary path of migration of humans to the Americas? If it wasn’t, then how did humans get there?

Theories on this are evolving, and there isn’t yet a consensus on the subject.

The most popular theory, and one supported by the realities of the ice bridge and companion artifacts from Japan and Cooper’s Ferry, is the Kelp Highway hypothesis.

The theory is based on the extensive kelp forest ecosystem along the Pacific rim from Japan to Northern Asia, across Beringia, and down the Pacific Coast.

Early mariners may have sailed along the coastline in small craft, feeding on kelp, but more likely enjoying the bounty of marine life in this ecosystem.

Humans had made similar-length journeys in the Pacific for thousands of years before the dates attributed to traffic along the Kelp Highway.

Historians knew the journey was possible; they were simply blocked from entertaining the notion because it ran counter to the Clovis-First orthodoxy.

The Kelp Highway theory is difficult to prove, and detractors of the theory would point to the lack of boat evidence as a direct link.

A great example of the challenges facing the Kelp Highway hypothesis rests in the recent excavations near the Channel Islands, just off the coast of Santa Rosa, California.

The evidence that has emerged has been tantalizing for archaeologists. The spear points found in this region are closer to Japanese points than to Clovis points.

The big problem is that sea levels are so different today than they were 15,000 years ago. At that time, sea levels were estimated to be approximately 150 feet, or 50 meters, lower than they are today.

Any coastal settlements from that period would have been swallowed by the sea thousands of years ago.

The tight, coherent narrative of the Clovis First hypothesis made it an attractive theory, which is why it was so hard for some to let go of it.

After decades of evidence, the tide might finally be turning as more and more researchers come to accept that humans were in the Americas even earlier than we thought.

This change, however, hasn’t come from changing people’s minds so much as it has come from new researchers entering the field, proving the principal set forth by the physicist Max Plank who said, A new scientific truth does not triumph by convincing its opponents and making them see the light, but rather because its opponents eventually die and a new generation grows up that is familiar with it …