Very few people in the modern world obtain their food supply by hunting and gathering the natural environment surrounding their homes. This method of harvesting from nature's vision, however, is not only the oldest known subsistence strategy but also the one that been practiced continuously in some parts of the world for at least the last two million years. It was, indeed, the only way to obtain food until rudimentary farming and very crude methods for the the domestication of animals were introduced about 10,000 years ago.
Because hunter-gatherers have fared poorly in comparison with their agricultural cousins, their numbers have dwindled, and they have been forced to live in the marginal wastelands. In an higher latitudes, the shorter growing season has restricted the availability of plant life. Such conditions have caused a greater dependence on hunting and, along the coasts and waterways, on fishing. The abundance of vegetation in the lower latitudes of the tropics, on the hand, has provided a greater opportunity for gathering a variety of plants. In short, the environmental differences have restricted the diet and have limited possibilities for the development of subsistence societies.
Contemporary hunter-gatherers may help us understand our prehistoric ancestors. We know from observation of modern hunter-gatherers in both Africa and Alaska that a society based on hunting and gathering must be very mobile. Following the food supply can be a way of life. lf a particular kind of wild herding animal is the basis of the food for a group of people, those people must move to stay within reach of those animals. For many of the native people of the great central plains of North America, following the buffalo, who were in turn following the growth of grazing foods, determined their way of life.
For gathering societies, seasonal changes mean a great deal. While the entire community camps in a central location, a smaller party harvests the food within a reasonable distance from the camp. When the food in the area is exhausted, the community moves on to exploit another site. We also notice a seasonal migration pattern evolving for most hunter-gatherers, along with a strict division of labor between the sexes. These patterns of behavior may be similar to those practiced by humankind during the Paleolithic Period.