Grasses and the Culture History of Man

The beginnings of plant and animal husbandry are lost in antiquity. It is not possible to determine from the available archaeological record when plant domestication was initiated. Changes in phenotype, however, known to be associated with cereal species under domestication, and preserved in the archaeological record indicate that growing crops was an established way of life some 10,000 years ago. There are four major domesticated cereal complexes. Three evolved in the Old World and one in the New World. Wheat, barley, rye and oats are Near Eastern cereals, and spread across Eurasia early during the history of agriculture. Rice is the principal cereal of South Asia, sorghum and pearl millet the major cereals of the African savanna, and maize is a domesticate of Mesoamerica. Why the shift from hunter-gatherer to settled agriculturist occurred during the culture history of man is not known. Food production may have been initiated when man was faced with a gradual reduction in productivity of effort required to maintain accepted standards of living, traditional group size, and social organization. Once initiated, population pressures in particular will tend to demand agriculture. Hunter-gatherers live in equilibrium with the environment and have little lasting effects on nature. Farming, by its very nature, destroys the natural environment. Habitats are permanently altered, and a return to hunting and food gathering becomes impossible. Survival of civilized man has become absolutely dependent on cereal agriculture. Overpopulation, depletion of resources, planetary pollution, and the social ills of cities are penalties we have to pay for the pleasures of an abundant and stable food supply. Grasses have been playing a principal role in shaping the culture history of man every since he became sapient. They are basic to human life. The staple food of the great majority of mankind comes from grasses and they provide food for the grazing animals from which man derives most of his protein. The Gramineae is a relatively young but successful family. It includes an estimated 600 genera and 8,000 species that are widely distributed across the world. Grasses occur on all continents, including Antarctica, and are absent only from regions that are too barren or too cold to support the growth of flowering plants. The fossil record of grasses is meager, but there is good evidence to suggest that they emerged as a distinct family during late Cretaceous times when the flowering plants were spreading throughout the world. By early Miocene grasslands probably were assuming a prominent place in the earth's vegetation, and it is estimated that at present almost one-quarter of the world's plant cover is composed of grass (Barnard, 1969). The evolution of the family has been strongly influenced by herbivorous mammals. Early ungulates were probably browsing, rather than grazing animals. Nonruminant kinds of Artiodactyla appear in the fossil record from the early Tertiary. Ruminant forms, particularly the Bovinae, arose during the Miocene and have coevolved with grasses ever since. The transverse intercalary growth zone in leaves and above culm nodes, the short internodes of aerial stems of annual grasses, and the tufted habit of perennial grasses during vegetative growth, are adaptations to withstand grazing. Man appeared on the scene well after the Gramineae and grazing ungulates became widely dispersed. Hominid evolution dates back to the Pliocene, but the