Anthropology

The advent of geology and the study of fossil sequences in the late eighteenth and early nineteenth centuries by pioneer geologists such as James Hutton (1726–1797) and Sir Charles Lyell (1797–1875) who laid the groundwork for the study of human evolution. Two major events in the 1850s loom large in the history of this most basic of the subfields: (1) the accidental discovery in 1856 of the first premodern human being, the prototype of the Neanderthals, in a quarry near Düsseldorf, Germany, and (2) Charles Darwin's (1809–1882) theory of "natural selection," articulated in On the Origin of Species (1859). This theory gave scholars who wanted to study the course of human evolution systematically a theoretical framework for determining how one species evolved over time into another.

The human fossil evidence in Europe, and eventually throughout the Old World, from Africa to China and Indonesia, mounted rapidly, and by the early twentieth century anthropologists had developed several models of human evolution. At first, there appeared to have been two successive species of genus Homo: Homo sapiens, including all modern human beings as well as our immediate precursors, the Neanderthals, and the far older Pithecanthropus erectus, the earliest example of which was found near Solo on the island of Java in 1895. It had become clear that the human species was at least several hundred thousand years old. As the twentieth century unfolded, new and even older hominid fossils were discovered, primarily in Southern and Eastern Africa, and both the dates and descriptions of hominid evolution changed markedly. The 1925 discovery of Australopithecus africanus in South Africa by Raymond Dart (1893–1988) pushed the origin of the hominids back at least a million years and added a new, pre-Homo genus, Australopithecus, or "Southern Ape-Man."

It is impossible here to outline the sequence of major fossil discoveries in Africa and elsewhere that have been made since 1925. The names of anthropologists responsible for these finds include the late Louis S. B. Leakey (1903–1972) and Mary Leakey (1913–1996), who, in the late 1950s and early 1960s, discovered a number of extremely important protohominids at Olduvai Gorge in northeast Tanzania. In 1974 Donald Johanson discovered "Lucy," an extremely early Australopithecine that lived in what is now southeastern Ethiopia around 3.1 million years ago, the prototype of Australopithecus afarensis. In 1994 fossil evidence of an even older genus and species of protohominids, Ardipithecus ramidus, more than a million years older than "Lucy" (c. 4.5 million years old), was found in the same region of Africa, and in the last several years fossil fragments found in East Africa push the origin of hominids even farther back, perhaps as much as 5.5 million years. Moreover, it is now suspected that hominid bipedalism evolved as early as 4.5 to 5 million years ago; by freeing our forelimbs, it affected the evolution of the capacity for culture profoundly by enabling our ancestors to use and make tools.

Of course, this did not happen overnight. The earliest evidence for the presence of crude tools, again in East Africa, dates from around 2.5 million years ago. By this time, the earliest species of our genus, Homo habilis, had evolved, followed by Homo ergaster (c. 1.9–1.5 million years ago), and then Homo erectus, which dominated the Old World from c. 1.5 million to about 200,000 years ago, when it began to be replaced, at least in Europe—Homo erectus appears to have lingered longer in parts of Asia—by the Neanderthals. They, in turn, were eventually displaced by our own immediate ancestors, anatomically modern hominids (Homo sapiens), who are now thought to have evolved around 130,000 years ago near the southern tip of Africa. By 27,000 years ago, Homo sapiens had replaced all other hominid species everywhere. Some biological anthropologists still subscribe to the "multiregional hypothesis" that human beings became "modern" simultaneously in several parts of the Old World, from Africa to Europe and East Asia about 40,000 to 50,000 years ago, but consensus in the profession supports the "out of Africa" model, strengthened by the absence of any evidence that Neanderthal mitochondrial DNA exists in modern European populations.

A significant element in this evolutionary journey was the development of our brains to the point that we were able not only to make crude stone tools but to envelope ourselves and the world around us in what cultural anthropologist Clifford Geertz has called "webs of significance," the capacity for culture. At the same time, it has become abundantly clear that, since the emergence of anatomically modern hominids, no appreciable differences in the capacity for culture have emerged among the several modern human physical types, what are still sometimes erroneously called "races," and that the behavioral and technological differences that separate contemporary human communities are cultural rather than biological. One of the most important contributions of biological anthropology to general knowledge has been to dispel the pernicious myths of racial superiority and inferiority.

In addition to tracing the course of human evolution, many biological anthropologists specialize in the comparative study of chimpanzees (e.g., Jane Goodall), gorillas (e.g., the late Dian Fossey [1932–1985]), and other nonhuman primates, hoping to throw additional light on human behavior and the extent to which it is grounded in our primate heritage. Such studies provide a better understanding of the profound biological changes in our ancestors during the last five million years, changes that culminated in Homo sapiens.

While biological anthropology is best known for the study of ancient humans and other primates, other branches of the field also make significant contributions. Forensic anthropologists assist law enforcement agencies in gathering and interpreting evidence in cases of homicide, massacres, and genocides; other biological anthropologists study the interaction of culture and biology as it affects our health, longevity, and well-being. Such researchers work on a range of topics including the spread of AIDS (autoimmune deficiency syndrome) and other communicable diseases; the relationship between health and social problems such as poverty, racism, and inequality; stress and rapid social change; diet and maternal well-being; and the long-term effects of violence and warfare. There is a close relationship between this type of biologically focused anthropology and the work of medical anthropologists, cultural anthropologists who study the social contexts of medical practice.