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.
Alternative theories
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 twenty-first 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.
Other origins
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.
Linguistic theory
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.