No organism can survive without nutrients essential to build its structure and fuel its functions. Food has been a driving force in human evolution. One important criterion for categorizing human cultures is based upon food getting or subsistence patterns. Subsistence has important ramifications for other aspects of culture as well. In terms of human evolution, the three main branches of the hominin line—Australopithecus, Paranthropus, and Homo each adapted to their respective environments and chose different food getting strategies, and their eventual success or demise was largely conditioned by those choices.

Homo, aided by a larger brain and more advance tool-making abilities, added scavenged meat to their diet, providing added flexibility. This in turn permitted continuing evolution when further environmental change led to the extinction of the other two branches. Expansion into Africa and other Old World continents exposed early hominins to new and changing conditions.

Scavenging was replaced by hunting, but in many parts of the world, gathering plant foods was and is the more important nutritional source. In Anthropology, misinterpretation of the importance of hunting over gathering has long been based upon sexism. Also, there has been an exaggerated emphasis by foraging groups themselves. Nutritional studies prove otherwise.

Another important food-related aspect of evolution was tool use. Facial reduction, especially teeth and the jaw indicated their former use as tools due to technological advances in stone tools. Subsistence patterns are often divided into 2 main types—food-collecting and food-producing. Often, both patterns exist in parallel in most societies, with one pattern supplying the bulk of the diet.

Perhaps the most important relationships between a species and its environment focus on the processes of food acquisition. For humans, the ways in which societies acquire their food—their subsistence patterns—are so central that we may use them to categorize types of cultures. Thus, we speak of a society as food collecting or food producing. A synonym for the former is foraging. Within the latter are the subcategories of horticulture, pastoralism, and agriculture.

Many, if not most, of the other basic features of a cultural system can be seen as more or less related to subsistence pattern. Generalizations are possible with regard to such things as mobility, population size, basic economics, social stratification, labor specialization, kinship, and religion.