New evidence from earliest known human settlement in the Americas

New evidence from the Monte Verde archaeological site in southern Chile confirms its status as the earliest known human settlement in the Americas and provides additional support for the theory that one early migration route followed the Pacific Coast more than 14,000 years ago.

The study was conducted by a team of anthropologists, geologists and botanists headed by Vanderbilt University’s Distinguished Professor of Anthropology Tom Dillehay and was reported in the May 9 issue of the journal Science.

The paper, which includes the first new data reported from the site in 10 years, includes the identification of nine species of seaweed and marine algae recovered from hearths and other areas in the ancient settlement. The seaweed samples were directly dated between 14,220 to 13,980 years ago, confirming that the upper layer of the site, labeled Monte Verde II, was occupied more than 1,000 years earlier than any other reliably dated human settlements in the Americas.

The Monte Verde site was discovered in 1976. It is located in a peat bog about 500 miles south of Santiago and has revealed well-preserved ruins of a small settlement of 20 to 30 people living in a dozen huts along a small creek. A wide variety of food has been found at the site, including extinct species of llama and an elephant-like animal called a gomphothere, shellfish, vegetables and nuts.

In 1979, when Dillehay and his colleagues first reported that the radiocarbon dating of the bones and charcoal found at Monte Verde returned dates of more than 14,000 years before the present, it stirred up a major controversy because the early dates appeared to conflict with other archaeological evidence of the settlement of North America.

Since at least 1900, the prevailing theory had been that human colonization began at the end of the last Ice Age about 13,000 years ago, when groups of big game hunters, called the Clovis culture, followed herds from Siberia to Alaska over a land bridge across the Bering Strait and then gradually spread southward. None of the Clovis artifacts were dated earlier than 13,000 years ago. So having a substantially older human settlement in southern Chile was difficult to reconcile with this view.

It wasn’t until 1997 that the controversy was resolved by a prominent group of archaeologists who reviewed the evidence, visited the Monte Verde site and unanimously approved the dating.

Most scholars now believe that people first entered the new world through the Bering land bridge more than 16,000 years ago. After entering Alaska, it is not known whether they colonized the hemisphere by moving down the Pacific coast, by inland routes or both. The general view is that the early immigrants would have spread down the coast much faster than they could move inland because they could exploit familiar coastal resources more readily and get much of their food from the sea. However, evidence to support the coastal migration theory has been particularly hard to find because sea levels at the time were about 200 feet lower than today: As the sea level rose, it would have covered most of the early coastal settlements.

According to Dillehay, the new Monte Verde findings provide additional support for the coastal migration theory but, at the same time, raise the possibility that the process may have been considerably slower than currently envisioned.

At the time it was inhabited, Monte Verde was situated on a small tributary of a large river. It was about 400 feet above sea level and located more than 50 miles from the coast and about 10 miles from a large marine bay. Despite its inland location, the researchers identified a total of nine different species of seaweed and algae in the material collected at the site — material that the Monte Verdeans must have brought from the coast and the bay. The researchers have also found a variety of other beach or coastal resources, including flat beach pebbles, water plants from brackish estuaries and bitumen.

“Finding seaweed wasn’t a surprise, but finding five new species in the abundance that we found them was a surprise,” said Dillehay. “There are other coastal resources at the site. The Monte Verdeans were really like beachcombers: The number and frequency of these items suggests very frequent contact with the coast, as if they had a tradition of exploiting coastal resources.”

In addition, the scientists have found a number of inland resources, such as the gomphothere meat, in the ancient village. This suggests that the group was moving back and forth between different ecological zones, a process called transhumance.

“It takes time to adapt to these inland resources and then come back out to the coast. The other coastal sites that we have found also show inland contacts. If all the early American groups were following a similar pattern of moving back and forth between inland and coastal areas, then the peopling of the Americas may not have been the blitzkrieg movement to the south that people have presumed, but a much slower and more deliberate process,” Dillehay observed.

Source: Vanderbilt University

Related stories:

Patagonian glacier yields clues for improved understanding of global climate change
Although ice cores obtained from Antarctica have now provided more than 800 000 years’ worth of climate records, analysis of them alone is insufficient for understanding the history of climatic interactions between the diverse regions of the world. Boreholes drilled during the 1990s on six glaciers in the tropical zone of the Andean Cordillera gave rise to a substantial collection of data on the changes and developments of the tropical climate of the Southern Hemisphere.
Researchers find pre-Clovis human DNA
DNA from dried human excrement recovered from Oregon's Paisley Caves is the oldest found yet in the New World -- dating to 14,300 years ago, some 1,200 years before Clovis culture -- and provides apparent genetic ties to Siberia or Asia, according to an international team of 13 scientists.
Living fossil still calls Australia home
They are separated by a vast ocean and by millions of years, but tiny prehistoric bones found on an Australian farm have been directly linked to a strange and secretive little animal that lives today in the southern rainforests of South America.
Drier, warmer springs in US Southwest stem from human-caused changes in winds
Human-driven changes in the westerly winds are bringing hotter and drier springs to the American Southwest, according to new research from The University of Arizona in Tucson.
Bridging the math gender gap
The gender gap in math perceived to exist between girls and boys has long been contested. New research published in the journal Science sheds clarity on the debate and demonstrates that girls perform better in mathematics in more gender equal societies, in some cases besting male peers.
20,000 cranes take rest in Colorado
Thousands of Sandhill Cranes have converged on Colorado's Monte Vista National Wildlife Refuge for a stopover before they head north.
Key to controlling drug resistant bacteria
When you check into a hospital, the odds are one in ten that you will become infected with a strain of antibiotic-resistant bacteria as a result of your stay. That is because the problem of drug-resistance has become endemic in today's hospitals despite the best efforts of the medical profession. In the United States alone this currently causes about 100,000 deaths per year.
The Best Way to Board a Plane
Most airlines board passengers the same way, first filling the seats in the back of the plane, and then moving to the front. After a recent experience boarding a plane in this manner, Fermilab physicist Jason Steffen wondered if there might be a better way. So, in the midst of studying gravitation and axion-like particles, Steffen took a short break to investigate an optimal boarding method for airline passengers.

News discussion:

General Science news