Migration Mysteries

Cactus Hill, Virginia

At a site in Virginia called Cactus Hill, archaeologists have found an assemblage of artifacts that challenges scientific ideas about the first Americans. The conventional wisdom was that Native Americans are descended from a small band of people from northeast Asia who crossed over a now-vanished land bridge that extended between Siberia and Alaska between 12,000 and 15,000 years ago.

But the artifacts at Cactus Hill dated back to 16,000 B.C. What’s more, stone spear points found at the site are reminiscent of those made by a Stone Age culture in southwest France, called the Solutreans, that ended 18,000 years ago.

Archaeologist Dennis Stanford has suggested that the first Americans were actually the Solutreans, who crossed the Atlantic in boats similar to ones used by Arctic Eskimos. According to this controversial idea, the Solutreans were among the first New World explorers and may have been the ancestors of another ancient American culture, the Clovis people, who lived about 13,000 years ago.

In recent years, the idea that there may have been multiple migrations to the Americas by several groups of people beginning as far back as 16,000 or 18,000 years ago appears to be supported by a growing body of genetic, linguistic, and physical evidence.

Dhofar, Oman

The recent discovery of over a hundred sites in the Sultanate of Oman, located in the southeastern corner of the Arabian Peninsula, could change how scientists think about the ancient migration of our ancestors out of Africa.

According to one idea, called the coastal expansion hypothesis, early modern humans left Africa about 60,000 years ago and spread throughout Europe and Asia by following the coastline. But stone spear points and other artifacts discovered at Oman that date to about 106,000 years ago suggest that a “Nubian Middle Stone Age” culture once thrived in southern Arabia.

The spear points appear to have been created using a technique similar to one used by a nomadic hunter-gatherer society from Africa’s Nile Valley known as the “Nubian Complex.” According to archaeologist Jeffrey Rose, the evidence from Oman provides a “trail of stone bread crumbs” left by early humans who migrated out of Africa and into Arabia by following a network of rivers inland. The climate in Arabia was tropical during the time the Stone Age humans lived there, scientists say, and would have been home to abundant freshwater and plentiful game such as gazelles and antelopes.

Kennewick Man

In 1996, a 9,300-year-old skeleton was accidentally discovered along the Columbia River in Kennewick, Washington, during a hydroplane race. The U.S. Army Corps of Engineers initially turned the skeleton over to a coalition of Native American tribes, who claimed Kennewick Man as their ancestor and who wanted to bury him according to tribal tradition. But scientists filed a federal lawsuit to gain permission to study the skeleton, and in 2004, a federal judge decided to grant the request after determining that the tribes could not prove a direct cultural affiliation with Kennewick.

An analysis of the skeleton in 2005 determined that Kennewick Man was purposefully buried and had suffered various physical traumas before dying in his mid-to-late 30s. He was a well-built individual, and his right arm was larger than his left, which likely resulted from frequent use of an atlatl, or spear thrower, which he and his contemporaries could use to hurl a spear up to the length of a football field to kill prey.

Some of the scientists who studied the Kennewick Man skeleton suggested his facial features were European, while others argue that his skull shape is most similar to a Japanese group called the Ainu. National Geographic Explorer-in-Residence and Genographic Project founder Spencer Wells says Kennewick is typical of other early (pre-8,000 years ago) American skulls in this regard; most of them exhibit features more typical of European populations than later remains.

Monte Verde, Chile

The Monte Verde archaeological site is located in the low mountains of southern Chile and has been dated to more than 14,000 years old. Artifacts discovered at the site include mastodon bones, charcoal-filled hearths, and wooden posts that once supported huts. Its discovery in the late 1970s suggested humans had not only arrived in the Americas a lot earlier than expected, but that they had also traveled a lot farther than anyone thought.

In 2008, archaeologists discovered bits of chewed up seaweed at the site that may have been used for food and medicine and which corroborate the dating of other artifacts at the site. Several different species of seaweed were discovered, which suggests that early Americans possessed a fairly sophisticated knowledge of coastal ecosystems.

Based on this evidence, some researchers have suggested that ancient humans spread across the Americas through a slow coastal migration down the Pacific Coast, instead of dispersing along strictly inland routes as had been traditionally thought. Archaeologist Tom Dillehay speculates that people could have moved in a “zigzag” pattern—taking inland detours to follow “thousands of temptations” along the way before returning back to the coast to continue their southward migration.

Meadowcroft Rockshelter, Pennsylvania

Located near Pittsburgh, Pennsylvania, the Meadowcroft Rockshelter site is a rock ledge overhang that was used as a campsite by prehistoric hunters and gatherers some 16,000 years ago. Discovered in 1955, Meadowcroft Rockshelter is the oldest known site of human habitation in North America and its existence lends credence to the idea that humans arrived in the Americas earlier than traditionally thought. The site has yielded nearly two million artifacts, including ancient tools made of stone or bone, pottery fragments, and hundreds of fire pits. Animal and plant remains—including fruits, nuts, and seeds—have also been discovered at the site.

Stone Age India

After first leaving Africa, modern humans may have veered east to settle India some 76,000 years ago—tens of thousands of years before they are thought to have arrived in Europe. According to paleoanthropologist Michael Petraglia, who is developing the theory, early modern humans may have wiped out another human species, Homo heidelbergensis, which scientists think left Africa about 800,000 years ago and who was already living in India.

The scenario Petraglia envisions is eerily similar to what some scientists think happened in Europe about 30,000 years ago, with modern humans driving their close cousins the Neanderthals to extinction. The modern humans who colonized India may also have been responsible for the disappearance of another species, Homo floresiensis (aka “the hobbits”), whose fossilized bones have been discovered on the Indonesian island of Flores, Petraglia says.

Peking Man

In 2008, Chinese archaeologists claimed that a newly unearthed skull that dated back 80,000 to 100,000 years belonged to an early modern human. China’s government-run press hailed the discovery as “the greatest discovery in China after Peking Man”—a subspecies of Asian Homo erectus that was discovered in the 1920s and which for a time caused some anthropologists to suggest that China was the original homeland of humanity. (That idea was later discounted by discoveries in Africa.)

If the new skull did indeed belong to a modern human, it would have forced a radical rethink of theories about when our ancestors first left Africa because it would have indicated a very early dispersal of modern humans eastward from Africa and the Middle East. But other experts have discounted this idea, saying the Chinese skull resembles Peking Man more than it does modern humans.