In the geologic time scale devised by scholars, the Age of Mammals is called the Cenozoic era. The period in the Cenozoic era in which humankind came into existence is called the Pleistocene epoch. During the Pleistocene epoch, which is thought to be at least a million years long, the world experienced a series of four ice ages. In each of these ice ages, much of the world was covered with glaciers. Between the ice ages were periods of warmer weather and melting ice. During the last of the four ice ages, humans first arrived in the Americas.
It is theorized that during the last ice age, so much of the earth’s water was locked up in glaciers that the oceans were lower than today and more land was thus exposed. Where there is now water between Alaska and Siberia (eastern Russia)—known as the Bering Strait—there was once a wide strip of land on four different occasions, each about 5,000 to 10,000 years long, during the last 60,000 years. Scholars refer to this once-exposed land-mass as the Bering Strait land bridge, or Beringia.
Animals could have migrated across this land bridge—now-extinct creatures such as mammoths, mastodons, bighorn bison, and saber-toothed tigers. And the ancient ancestors of the Indians—the big-game hunters who depended on these animals for food—could have followed them out of Asia to North America. Other peoples on the move may have come by water routes.
The exact time that the first bands of hunters and their families arrived in North America is not known. The estimated time cited by scholars for years, based on early archaeological evidence, was sometime before 11,200 years ago. More recent finds have pushed the date back to sometime before 12,500 years ago. Growing evidence at a site in Chile known as Monte Verde is pushing the estimated date as far back as sometime before 33,000 years ago. New archaeological finds alter the theoretical time frame. Linguistic studies using computer projections have indicated that too many Native language families (as many as 150) exist in the Americas today to have evolved in 10,000 or so years. According to these results, 40,000 years ago is a more likely approximation for the arrival of the first Americans.
In any case, the migration of humans from Asia to North America did not happen all at once, but in many waves of small bands along the same route. Over the following thousands of years, their descendants worked their way southward, probably first during a temporary melt, following an ice-free passage along the Rocky Mountains, before dispersing throughout much of the Americas.
The first Indians, the true discoverers of the Americas, had only wooden and stone tools and no metal. The period in human evolution before the invention of metal tools is known as the Stone Age, or the Paleolithic Age. The earliest Indians are called Paleo-Indians, or Lithic Indians.
The Paleo-Indians lived for the most part in caves, under overhangs, and in brushwood lean-tos. They wore hide and fur clothing. They used fire to keep warm, to cook, to protect themselves from animals while sleeping, and to hunt. By lighting fires on the grasslands, the hunters could drive herds of animals over cliffs and into swamps and bogs, where they could be killed. The early Indians had various methods for lighting fires: striking a spark with certain stones, such as flint, or by rubbing wood together. Fire drills, made from two sticks and a strip of rawhide, enabled the rapid spinning of wood against wood to generate enough friction to ignite wood powder or other vegetable material.
In addition to woolly mammoths, mastodons, bighorn bison, and saber-toothed tigers, the Paleo-Indi-ans hunted other extinct species: American lions, camels, short-faced bears, dire wolves, giant beavers, giant sloths, giant armadillos, curve-snouted tapirs, musk oxen, peccaries, native horses, plus smaller game. The first Indians were also gatherers of wild plant foods: greens, seeds, berries, roots, and bulbs.
The craftsmanship of the Paleo-Indians was essential to their big-game hunting way of life. The early Indians had techniques for making spearheads razor-sharp. The first Paleo-Indians did not have stone-pointed spears. They probably used fire to harden the tips of wooden spears, but this theory is unproven because the wooden spears decayed long ago. The earliest Indians did, however, have roughly shaped stone and bone tools for scraping and chopping. Later Paleo-Indians developed methods of shaping certain types of stone—especially flint, chert, and obsidian—into sharp points and edges. In percussion flaking, they removed chips and sharpened the point by striking it with a stone. In pressure flaking, they pressed antler or bone tools against the point to shape and sharpen it.
Scholars use the different types of points found at campsites, hunting sites, and quarry sites to determine different technological phases, traditions, or cultures among the Paleo-Indians. For example, the Clovis culture is named after the Clovis site in New Mexico, but Clovis-style points have been found all over North America, usually with mammoth and mastodon bones. They were one and a half to five inches long, with fluting (lengthwise channels) along both sides of the base, where they were attached to wooden shafts. The Clovis points have been dated from about 9200 to 8000 B. C.
Clovis point
The Sandia culture, named after a cave site in the San-dia Mountains of New Mexico, was characterized by stone points two to four inches long with rounded bases and a bulge on one side where they were attached to wooden shafts. The Sandia points have been dated from about 9100 to 8000 B. C. The culture was located in the Southeast.
Sandia point
The Folsom culture is named after the Folsom site in New Mexico. Evidence of Folsom hunters has been found mostly in the Southwest and Far West, but also on the Great Plains along with the remains of bighorn bison. The Folsom tradition lasted from about 9100 to 8000 B. C. The Folsom points, three-quarters of an inch to three inches long, were unique in that they had fluting on both sides running almost the entire length of the point. It is theorized that these long channels, which are very difficult to make in stone, served an additional purpose besides helping to attach the point to the spear shaft. Perhaps they increased the flow of blood from an animal or increased the spear’s velocity when it was thrown.
Northward once and for all. The Ice Age became what is sometimes referred to as the Watershed Age. The melting ice created numerous lakes and swamplands, many of which would eventually evaporate. North America gradually evolved to its present form by about 5000 B. C.
The changing climate probably contributed to the extinction of the big-game animals. The Paleo-Indians might also have played a part in this phenomenon. They became such skilled hunters—using atlatls and communal drives of huge herds—that they killed more game than they needed. Archaeologists hold this theory because they have found at kill sites the bones of many large animals with stone points in them. This killing of more animals than necessary has been referred to as the Pleistocene Overkill.
Some time during the Paleolithic Age, Folsom Native Americans began first using spear-throwing devices called atlatls. These were wooden sticks about two feet long with animal-hide hoops to provide a firm grasp, a stone weight for balance, and a hook to hold the spear shaft. With an atlatl, a hunter had increased leverage that allowed him to fling his spear harder and faster. (Bows and arrows were not invented until much later.)
The Plano, or Plainview, culture, named after the Plainview site in Texas, is also associated primarily with the Great Plains and the bighorn bison. Plano craftsmen did not flute their points, however. The Plano Indians also demonstrated a more varied culture than the Indians before them. For example, they built corrals to trap animals. They also developed a method of preserving meat by mixing it with animal fat and berries and packing it in hide or gut containers. The Plano period lasted from about 8000 to 4500 B. C.
World History
