First Americans, Origin Theories of
First Americans, Origin Theories of
Thousands of years ago, bands of people traveled to North and South America from faraway homes and they stayed, becoming the first Americans. These early migrations (movements in groups from one home to another) remain a mystery. No one knows when the first Americans came, where they came from, or whether they traveled by boat or by foot. It is also unknown how many different migrations there may have been. New evidence has emerged that disproves long-accepted views about the first migrations to the Americas and experts in the early twenty-first century have made some educated guesses based on an abundance of new evidence and research.
Bering Land Bridge and the Clovis theory
Scientists believe that a glacial period (a period of extreme cold when great portions of the earth were covered with masses of ice called glaciers) began around one hundred thousand years ago. So much water froze that the sea level dropped to about 300 or 400 feet below what it is today. Scientists theorize that the low water level exposed a vast land bridge spanning the distance across the Bering Strait, from Siberia in northern Russia to the northwest tip of North America (present-day Alaska ). The Bering Land Bridge probably remained exposed until about twelve thousand years ago when the climate began to warm.
From the late 1950s to the end of the century, most scholars believed that the first Americans migrated from northeast Asian areas such as China, Siberia, and Mongolia by walking across the Bering Land Bridge in pursuit of big game. According to this theory, within about one thousand years, these big game hunters populated the American continents, from northern Canada to the southernmost tip of South America, and they gradually developed into what is now known as the Clovis culture. Artifacts (things made by humans) of the Clovis culture, such as carefully crafted spear points and tool kits, were found throughout the United States and parts of Central America that date back to 9000 bce.
Scientists thought these were the remnants of the earliest life in the Americas.
In 1977, artifacts of an even earlier human settlement were found at Monte Verde in south-central Chile that were at least 12,500 years old. Gradually, even older sites were found. By the beginning of the twentyfirst century, most scientists were convinced that the Clovis people were not the first Americans. Some scientists have found evidence that the earliest populations may have come from origins other than northeast Asia; some have presented alternatives to the Bering Land Bridge theory; and many now believe that there was more than one migration.
According to the Bering Land Bridge theory, early Americans traveled the ten-thousand-mile distance from the land bridge to the southern reaches of South America in a period of one thousand years. Some scientists doubt that each generation would keep moving at this kind of rate over that period of time. They theorize that at least part of the journey took place in boats.
One group of scientists noted a similarity between Clovis tools and the tools of the Solutrean culture, a European culture that developed around France about twenty thousand years ago. They think that the Solutreans traveled by boat across the Atlantic Ocean about twelve thousand years ago, navigating among glaciers and islands, and settled in the area that is now the southeastern United States. These people would have been the ancestors of the Clovis people. Many scientists dispute this Solutrean theory for its lack of evidence.
Experts assumed that the first Americans were northern Asians from Mongolia, Siberia, and China because modern American Indians share physical characteristics with these northern Asian people. Recent evidence, however, points to other groups being present on the continent before the northern Asians. Analysis of ancient skeletons has shown that some have Caucasian or Negroid rather than Mongoloid features, meaning they came from white or black racial stock rather than Asian racial stock. The skeletons with non-Mongoloid features are actually older than any of those found from the northern Asian stock.
Some of the ancient skeletons have similarities to a native Japanese group called the Ainu; others resemble Southeast Asians; some resemble Europeans. The scientists pursuing these alternative origins theories propose that groups of people known as the Paleoamericans migrated to the Americas at an unknown date and lived there before the northern Asians (the Paleo-Indians) arrived. The Paleoamericans either perished in warfare with the Paleo-Indians or the two groups merged through intermarriages and their descendants took on the current physical traits of American Indians.
In the 1980s and 1990s, linguist Joanna Nichols undertook a large study of American Indian languages and found 150 language families on the North and South American continents. Nichols argued that the Americas had to have been inhabited by humans for at least thirty thousand to forty thousand years to account for the language development that occurred, and she thinks that three different migrations took place.
Nichols has proposed the following sequence of migration, based on language variations: about thirty thousand to forty thousand years ago, humans crossed the Bering Land Bridge and traveled down to South America; between fourteen thousand and twenty-two thousand years ago, the glaciers in the north spread, forcing humans to stay in the warmer climate of South America; about fourteen thousand years ago, humans in South America began to spread north, inhabiting North America; around twelve thousand years ago, another migration came across the Bering Land Bridge and spread down the coast; about five thousand years ago, another migration occurred through the waters near the land bridge, and these people settled in Alaska, Greenland, and Canada.
Scientists who have compared the genes (the basic units of heredity that are passed from one generation to the next and determine traits) of American Indians and Asians have reached similar conclusions about the time line of migrations. Although none of the new theories about the first Americans are accepted as the last word on the subject, they provided scientists with new ways of studying the early history of the Americas as evidence and new theories continue to emerge.