8 CHAPTER 1 ANCIENT AMERICA
ago. Revisionists point to discoveries, especially in
Chile and Brazil, that suggest a much earlier oc-
cupation. Most recently, the arguments in favor
of such an earlier occupation have been reinforced
by linguistic evidence that takes account of the im-
mense time span required for the formation of the
many languages spoken in Ancient America.
Two waves of migrations appear to have taken
place. The fi rst brought extremely primitive groups
who lived by gathering wild fruit, fi shing, and hunt-
ing small game. A recent archaeological discovery
suggests that these primitive hunters and gatherers
passed through Peru about twenty-two thousand
years ago. The second series of invasions brought big-
game hunters who, like their predecessors, spread
out through the continent. By 9000 BCE, these Asi-
atic invaders or their descendants had reached Pa-
tagonia, the southern tip of the continent.
This fi rst colonization of America took place in
the last part of the great geological epoch known as
the Pleistocene, a period of great climatic changes.
Glacial ages, during which blankets of ice covered
extensive areas of the Old and New Worlds, alter-
nated with periods of thaw, when temperatures rose
to approximately present-day levels. Even in ice-free
areas, precipitation often increased markedly dur-
ing the glacial ages, creating lush growth of pas-
tures and woodlands that supported many varieties
of game. Consequently, large sections of America in
this period were a hunter’s paradise. Over its plains
and through its forests roamed many large pre-
historic beasts. The projectile points of prehistoric
hunters have been found near the remains of such
animals from one end of America to the other.
Around 9000 BCE, the retreat of the last great
glaciation (the Wisconsin), accompanied by dras-
tic climate changes, caused a crisis for the hunting
economy. A warmer, drier climate settled over vast
areas. Grasslands decreased, and the large animals
that had pastured on them gradually died out. The
improved techniques of late Pleistocene hunting
also may have contributed to the disappearance of
these animals. The hunting folk now had to adapt
to their changing environment or vanish with the
animals that had sustained them.
The southwestern United States, northern
Mexico, and other areas offer archaeological evi-
dence of a successful adjustment to the new condi-
tions. Here, people increasingly found sustenance
in smaller animals, such as deer and jackrabbits,
and edible, wild plants, especially seeds, which
were ground into a palatable meal. This new way
of life eventually led to the development of agri-
culture. At fi rst, agriculture merely supplemented
the older pursuits of hunting and food collecting;
its use hardly constituted an “agricultural revolu-
tion.” The shift from food gathering to food pro-
ducing was more likely a gradual accumulation of
more and more domesticated plants that gradually
replaced the edible wild plants. Over an immensely
long period, time and energy formerly devoted to
hunting and plant collecting were diverted to such
agricultural activities as clearing, planting, weed-
ing, gardening, picking, harvesting, and food prep-
aration. But in the long run, agriculture, in the
New World as in the Old, had revolutionary effects:
people began to lead a more disciplined and sed-
entary life, the food supply increased, population
grew, and division of labor became possible.
In caves in the Mexican highlands, archaeolo-
gists have found the wild plants that were gradu-
ally domesticated; among the more important are
pumpkins, beans, and maize. Domestication of
these plants probably occurred between 7000 and
2300 BCE. Among these achievements, none was
more signifi cant than the domestication of maize,
the mainstay of the great cultures of Ancient
America. Manioc (a starchy root cultivated in the
tropics as a staple food) and the potato (in Peru)
were added to the list of important domesticated
plants between 5000 and 1000 BCE.
From its place or places of origin, agriculture
swiftly spread over the American continents. By
1492 maize was under cultivation from the north-
ern boundary of the present-day United States to
Chile. But not all indigenous peoples adopted agri-
culture as a way of life. Some, like those who inhab-
ited the bleak wastes of Tierra del Fuego at the far
tip of South America, were forced by severe climatic
conditions to either hunt and collect food or starve.
Others, like the prosperous, sedentary peoples of the
Pacifi c northwest coast, who lived by waters teeming
with fi sh and forests fi lled with game, had no reason
to abandon their good life in favor of agriculture.