Traditional anthropological theory has taught that the first humans made their way to the Americas by walking across ice sheets covering the small land gap between the continents, migrating from present-day Siberia to Alaska.
But recent studies by a University professor support a theory that may prove that textbook answer wrong.
University Anthropology professor Jon Erlandson has conducted research that suggests a different explanation for migration to the Americas.
His research contributes to an already existing theory called “Coastal Migration Theory,” which suggests that instead of migrating across Siberia, humans first made their way to the Americas by boat.
“Coastal Migration Theory,” was proposed as early as 100 years ago, said Erlandson. The theory hasn’t been widely accepted, however, until recently.
“It is now very much mainstream,” he said.
Erlandson proposed the theory that humans in boats sailed along the edges of forests of floating sea plants that stretched from what is now Japan, along Siberia and Alaska, and down the Northern American continent ending around the coast of California.
The sea plants, known as kelp forests, are diverse ecosystems that support a wide variety of plant and animal life that humans could have survived during the gradual migration. Erlandson said that kelp forests were ideal for people to travel and fish along. University professor of Anthropology Lynn Stephen said that Erlandson’s research has shaken up an established theory and had affected the way anthropologists conceived “the most important migration in human theory.”
Adjunct professor at the University of California Santa Cruz James Estes, who worked with Erlandson to develop the kelp highway theory, said that kelp forests were productive and advantageous places for people to live because of the abundance of food available.
Erlandson said, theoretically, the environment that humans faced on the “kelp highway” was constant, as opposed to the many different environments they would have been faced with had they traveled across the continent.
His “kelp highway” concept was first unveiled Feb. 19 at a recent Association for the Advancement of Science annual meeting. Because of an agreement he had with AAAS, he was not allowed to discuss his ideas with the press before the meeting.
Erlandson found holes in the more accepted theory.
One of the problems with the traditional migration theory is that humans have been on the coast of the Americas since 14,500 years ago, but a massive ice sheet would have blocked the land route at that time, he said.
The only way to get through the ice sheets would be to go through an opening or corridor in the ice, which anthropologists believed humans had passed through.
Scientists now know, he said, that there is no archeological evidence to support the theory that humans ever passed through such a corridor, which has never been proven to exist.
Even though the kelp highway theory has gained newfound acceptance there is currently no conclusive evidence to support it either.
Erlandson said gathering evidence to prove his theory is challenging since the sea level has risen 100 to 120 meters in the 14,500 years since the last ice age. Because of this climate change, much of the evidence that could help support the “kelp highway” theory may have been displaced by the ocean or eroded away.
Erlandson said that there may still be some evidence to be found in streams and caves along the coast. These spots may have provided early humans with shelter and a food source, he said.
Estes said that Erlandson’s “kelp highway” theory helps provide people with a better view of how humans reached the Americas, and that it brings a new modern ecological view in understanding how they reached the continent.
“It provides more focus for people to think about early humans based on early ecological thinking,” said Estes.
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