Diseases and Human Evolution

4: The Seeds of Change

CHAPTER 4 The Seeds of Change Prologue The final retreat of the massive ice sheets of the pleistocene took place between thirty-two thousand and ten thousand years ago, accompanied by fluctuating changes in the global environment. The subarctic tundra regions contained many of the last big game animals, such as mammoths, mastodons , and woolly rhinoceros. Massive herds of hoofed animals, such as wild bovines, wild horses, reindeer, and other deer, roamed the steppes of Central Asia, Europe, and North America. Pleistocene peoples living in present-day France and Spain revealed the creative side of human nature with rich artistic expressions in cave paintings. Stone tools became more refined and diverse, with many of them intended for use in working ivory, bone, antler, and wood (Smith 1972). Human migrations expanded into New Guinea and Australia, followed later by migrations to the New World and to South Pacific islands. Our ancestors refined and broadened their technology and skills of food procurement to better exploit a broader range of food resources found throughout the world’s various ecosystems. Food items included just about everything edible that was available to them: numerous small and large forest animals, as well as the large animals from the grasslands, along with fowl, mollusks, grubs, nuts, tubers, fruits, legumes, bulbs, greens, and seeds. Even then, notions of what was considered food, and practices of how and when it was procured, varied among different peoples. Grinding stones were 45 now used to pulverize acorns, nuts, and seeds (Henry 1989). Fishhooks, nets, and harpoons, along with skin boats, were used to reap bountiful supplies of fish, shellfish, and marine animals along the edges of the seas, rivers, and lakes (Piggott 1965). Global temperatures and moisture patterns shifted dramatically by the end of the Ice Age, thirteen thousand to ten thousand years ago. Many of the big game animals disappeared as the tundras shrank. The temperate zones and bordering ecological zones grew warmer with increased moisture, allowing woodlands to expand into former steppe regions. The climatic shifts altered the distribution of the plants and animals in many ecological zones. Plant and animal diversity increased with the expansion of ecotones, the transitional zones between different environments (Butzer 1964; Henry 1989), and human populations were quick to take advantage of these diverse offerings. Depending on environmental conditions, food sources and food procurement techniques varied. Some peoples relied more heavily on marine resources than on other sources of food, while others relied more on hunting . Hunting groups that depended on large herds of herbivores eventually learned to control small herds for their own use, guiding them to selected grazing and watering areas. This way, fresh meat and hides were always readily available on the hoof, with no need to go looking for them. This type of animal control, along with selective breeding and culling, eventually led to taming and domestication of sheep, goats, cattle, reindeer (Herre 1969), and possibly other deer (Dennel 1992). Marine exploitation, herding, hunting, and food foraging were so successful that several different human populations around the globe continued to pursue this way of life up into modern times. Pastoral peoples and maritime cultures of old continue in some parts of the world today, but many of them have modified their ancestral technologies with modern equipment. Political pressures forced most of them to change their way of life by the end of the twentieth century. Only a few remnant populations of hunters and foragers survived until the mid-twentieth century in scattered parts of the world. They provided a living history of our ancient past, and also taught us how readily humans can learn new ways, as modern tools and hunting weapons reached them. New ideas travel fast and are adapted quickly if they readily fit into the scheme of things. People tend to pick and choose what they wish to incorporate into their way of life, and so it was for ancient populations on the 46 CHAPTER 4 verge of revolutionizing food procurement methods through farming. Many peoples adopted the ideas associated with cultivation, while others chose not to incorporate farming into their way of life. The Best of Times The end of the Ice age brought a period of optimal climatic conditions and abundance, allowing human groups to thrive and increase somewhat in numbers. This modest increase came about as infant survival rates and adult longevity were promoted by the bounty...