Nature, Disease, and Globalization: An Evolutionary Perspective

Abstract

Contemporary globalization represents the culmination of a long evolutionary process that has produced larger and more complex social units over time. Although precursors of contemporary complex human societies emerged in eastern Africa more than 300,000 year ago, our interest in Homo sapiens, the globalizer, begins about 100,000 years ago when small bands of our species began to migrate out of eastern Africa toward the north and west. The factors responsible for this migration out of Africa remain speculative, but population growth, climate change, fluctuating food supplies, and human curiosity undoubtedly were involved. Within sixty to seventy thousand years, bands of Homo sapiens had settled in the far corners of the world, showing a remarkable ability to adapt to the most varied environments (Cavalli-Sforza and CavalliSforza 1995:56). According to Walter Wallace (1997:15), Homo sapiens has spent nine times as many years moving apart as the species has spent coming together. The greatest dispersal of these human societies (maximum social entropy) occurred between ten and fifteen thousand years ago. For most of human history the fates of these scattered clans and tribes were largely determined by the local constraints of nature as well as by the availability of food, water, and other resources and by local encounters with pests, predators, and pathogens. Over the last 5,000 years, however, beginning with the emergence of the great civilizations in western Asia, populations of Homo sapiens, for the most part, have grown significantly in size and density and have repeatedly been incorporated into larger and more complex units; these expansions and consolidations being precursors of processes that have culminated in contemporary globalization (McMichael 2001:103). These persisting social units now are increasingly being integrated into a very complex global system; their fates are no longer determined locally, but are increasingly being shaped by more global forces. It would not be easy, nor particularly rewarding, to quantify precisely the number of distinct human societies that have survived previous periods of consolidation and maintained their identities well into the twenty-first century. Because of the dynamics of contemporary globalization, however, their numbers are rapidly dwindling. The number of actively spoken languages in the world is a good surrogate measure. There are currently about 6,000 spoken languages, but linguists think that nearly one-half of them will be dead or dying within the next 50 years (Ostler 1999:34). The point here is not to lament the passing of these distinct societies, although cultural diversity is important. Rather, the focus is on the evolutionary dynamics that have been and still are associated with the integration of smaller social units into larger and more complex ones. Just as natural forces played a major role in shaping the prospects for and fates of early societies and agrarian-era empires, similar forces still shape, and perhaps will limit, the prospects for the deepening integration of remaining societies into a global system.