Coastal migration (Americas) facts for kids
The coastal migration hypothesis is a big idea about how the first people arrived in the Americas. It suggests that early humans traveled along the coastlines, using boats, instead of or in addition to walking through the middle of the continent. This journey might have started from Asia, going along the Kurile island chain, then past Beringia (a land bridge that used to connect Asia and North America), and finally down the coasts of Alaska and British Columbia all the way to Central and South America.
This idea is important because it's one of the main theories about how people settled the Americas during the Last Glacial Maximum (a time when huge ice sheets covered much of the Earth). Another theory suggests people walked through an "ice-free corridor" between two massive ice sheets, the Laurentide and Cordilleran ice sheets.
Scientists are finding more and more clues that support the coastal migration idea. For example, discoveries in caves on Vancouver Island show that the climate there might have been warm enough for people to live in as far back as 16,000 years ago, even when the ice sheets were still very large. This suggests that the coast could have been a path for early travelers.
Some researchers believe that people traveled along the coast from Alaska to the Pacific Northwest even before the Clovis people, who are known for their unique spear points, moved south through the ice-free corridor. It's possible that coastal travelers were already settled when the ice sheets melted enough for the Clovis people to follow.
A cool discovery happened in 2017 on Triquet Island. Archaeologists found a hearth (an old fireplace) that was between 13,613 and 14,086 years old! This makes it one of the oldest settlements ever found in North America and matches the First Nation oral stories about people living there during the Ice Age.
Interestingly, some scientists now think that the Clovis technology might have actually moved from the south *into* Alaska, rather than the other way around, after the big ice sheets melted about 10,500 years ago.
Even ancient dog remains support the coastal idea! The oldest dog bones in North America, found in Alaska, are about 10,150 years old. Genetic studies suggest this dog's family split from Siberian dogs about 16,700 years ago. This timing fits perfectly with when the North Pacific coastal route might have opened up.
Contents
Clues from the Coast
It's tricky to find very old coastal settlements because sea levels have changed a lot. When the glaciers melted, the sea rose and covered many ancient sites. However, scientists have found some early settlements above today's sea level, like Ground Hog Bay (10,200 years old) and Namu (9,700 years old) in British Columbia. These sites suggest people were already living along the coast after traveling there by water.
To truly understand how these early people lived, we need to imagine what the land and food sources were like back then.
Ancient Food and Land
Evidence from Southeast Alaska and Haida Gwaii (also known as the Queen Charlotte Islands) in British Columbia gives us clues about food and land resources. Scientists have found several sites on Haida Gwaii that are over 9,000 years old.
The oldest human remains found on the west coast of North America are from On Your Knees Cave on Prince of Wales Island in Southeast Alaska. This young man, who died around 10,000 years ago, mostly ate food from the ocean. This tells us that people living on the coast relied on the sea for their meals.
These findings suggest that when sea levels were lower, there was more land available along the coast. Many ancient sites might now be underwater. For example, between 13,000 and 10,500 years ago, Haida Gwaii was more than twice its current size! This extra land was flooded when the sea level rose quickly between 11,000 and 9,000 years ago. So, any very old settlements on that ancient coastline would now be deep under the sea.
The Kelp Highway
One exciting idea is the "Kelp Highway hypothesis." It suggests that early coastal travelers followed a "highway" of kelp forests along the Pacific Rim. These kelp forests are like underwater forests, full of life. They provide a rich environment for marine mammals, shellfish, fish, seabirds, and edible seaweeds. This abundance of food would have made it easier for hunter-gatherers to travel and survive along the coast.
Scientists believe these kelp forests would have been especially productive in certain areas of the Northern Pacific Rim due to the geography and ocean currents. Even though it's hard to know exactly what ancient kelp forests looked like, their presence would have offered a great food source for early coastal communities.
Archaeological Clues
Many archaeological sites from the Pacific Northwest down to California and even South America support the coastal migration theory. In California, sites like Borax Lake and the Santa Barbara Channel Islands show human settlement between 12,000 and 7,000 years ago. On the Channel Islands, scientists found marine shellfish remains linked to kelp forests, dating back 12,000 to 9,000 years ago.
In South America, the Monte Verde site in Chile has evidence of human presence as early as 12,500 years ago. This is important because the ice sheets would not have melted enough for inland travel by then, suggesting people arrived by the coast. The Monte Verde site even had remains of nine types of seaweeds, including kelp, showing a connection to coastal living.
More research shows that after the glaciers melted, the Pacific coastal areas became biologically rich, offering plenty of food and an easy route for early people to move along.
Animal Clues
Animal remains also give us clues. Goat bones as old as 12,000 years have been found on Vancouver Island, and bear bones from 12,500 years ago in the Prince of Wales Archipelago. Even older remains of black and brown bears, caribou, sea birds, fish, and ringed seals have been found in Alaskan caves. This means there were enough land and plant resources to support large animals, and therefore, humans too.
Boats and Travel
Scientists believe the coast was settled before 13,000 years ago, partly because of evidence of boats from Japan even earlier than that. In Indonesia, signs of offshore fishing, which needs boats, date back 35,000 to 40,000 years ago. This shows that people in Asia were skilled at sea travel. These skills and marine technology could have spread through the islands to Japan.
As the climate warmed around 16,000 years ago, it might have encouraged people to travel by sea up the Kurile island chain towards North America. Even though no ancient boats have been found from early Pacific Coast sites, this might be because organic materials like wood don't preserve well, and many coastal areas are now underwater. However, finding human-made tools on islands tells us that people must have used boats to get there.
Interestingly, the Bella Bella oral traditions, recorded in 1898, speak of a time "In the beginning there was nothing but water and ice and a narrow strip of shoreline." Some believe this story describes the Northwest Coast during the last melting of the glaciers.
Migration South
Further south, California's Channel Islands also show signs of early seafaring people. Sites on Santa Rosa and San Miguel islands date back to the end of the Ice Age, including the Arlington Springs Man site from around 11,000 years ago.
It's important to know that the Channel Islands were never connected to the mainland. So, people living there at the same time as the Clovis people on the mainland must have had seaworthy boats to reach them. The Channel Islands have also given us the oldest fishhooks found in the Americas, dating back about 8,500 to 9,000 years ago.
Even further south, the Monte Verde site in Chile is now accepted as the earliest settlement in South America, dating to at least 14,500 years ago. This strongly suggests that people migrated through northern coastal regions before that time.
Early Tools and the Western Stemmed Tradition
The early settlers on the California Channel Islands used finely made spear points, as well as crescent-shaped stone tools. These tools are similar to those found at many other sites across western North America, part of what scientists call the Western Stemmed Tradition (WST).
These ancient stemmed points have been found at many sites:
- In Texas, at the Buttermilk Creek Complex, tools are dated to about 13,500 to 15,500 years ago.
- At Paisley Caves in Oregon, WST points are about 12,700 to 13,000 years old.
- In Pennsylvania, a similar point at Meadowcroft Rockshelter is about 14,000 years old.
- In Mexico, stemmed points were found with mammoth bones, dating to similar times.
In South America, stemmed points, known as 'El Jobo points,' were used as early as 14,200 years ago at the Monte Verde site in Chile. These points became common across South America around 13,000 years ago.
On the Channel Islands, scientists have found early shell middens (ancient trash piles of shells) near places where people got chert to make stone tools. These sites, dating between 10,000 and 10,500 years ago, contain crescents and finely made stemmed points, likely used for hunting birds and sea mammals.
See also
