In a very simplistic way, we can view biological evolution as the result of interaction between the environment and the genetic make-up of the species. In order to adapt to changing environmental conditions, the genetics most favorable to the changed environment have a great chance of reproducing, thus facilitating biological evolution. With humans, however, culture is used to adapt to the environment, which allows humans to occupy very diverse environmental niches from equatorial forests, to deserts, to the arctic. This raises two basic questions: (1) Does culture evolve in a manner similar to that of biological evolution? and (2) Does culture influence biological evolution?
Does Culture Evolve?
In the nineteenth century, many people felt that biological evolution had progressed in a particular direction and therefore developed ideas that envisioned cultural evolution as also progressing in a particular direction. In 1877, Lewis Henry Morgan’s Ancient Society: or Researches in the Lines of Human Progress from Savagery Through Barbarism to Civilization identified various stages of cultural evolution: Savagery (Lower, Middle, Upper), Barbarism (Lower, Middle, Upper), and finally Civilization. Lower Savagery, which Morgan characterized as having a fruit and nut subsistence pattern, would have been the form of culture when humans first evolved. In Middle Savagery, humans began fishing and domesticated fire.
Under this scheme, American Indians were placed in either Upper Savagery or Lower Barbarism, depending on their material and political development. Morgan’s concepts were used in the formulation of Indian policies designed to “lift” Indians from “savagery” and “barbarism” to “civilization.”
Civilization was seen by Morgan as having a phonetic alphabet and writing. In addition, he put forth the idea that Civilization required the monogamous nuclear family and private property.
A number of other concepts of cultural evolution also emerged in the nineteenth century. In 1861, J. J. Bachofen envisioned an initial period of sexual promiscuity, followed by a period in which women liberated themselves through religion based on the worship of female deities. During this period, women established the family and marriage. Then, men sought to reverse the balance with a new form of religion based on fatherhood.
While Morgan viewed religion as being outside the scope of his theory of cultural evolution, many others, such as Bachofen, saw religion as a major force in cultural evolution. In his book The Rise of Anthropological Theory: A History of Theories of Culture, Marvin Harris reports:
“There was ample precedent for this attempt in the Enlightenment doctrine that man’s systems of belief were steadily moving toward higher forms of rationality which implied agnosticism if not atheism as an end state.”
Marvin Harris also writes:
“The theory that religious belief and institutions had undergone a natural evolution might be thought subversive with respect to revealed religion. Yet many of the late-nineteenth-century theorists not only clung to their childhood faiths but derived from them the added satisfaction that came from being convinced that their beliefs were demonstrably the highest form of religion.”
In his 1870 book The Origins of Civilization, John Lubbock proposed a series of stages for the evolution of religion, beginning with Atheism and culminating in a stage in which morality is associated with religion. Marvin Harris writes:
“Lubbock displays an infuriating certainty concerning the doctrinal superiority of his own brand of superstition.”
One of the problems of the nineteenth-century and early-twentieth-century concepts of cultural evolution is that they seemed to assume a kind of lineal progression from most primitive to most advanced in which the most advanced was their own European culture. The barriers imposed by ethnocentrism, racism, and paternalism limited their understanding of cultural evolution. In his book The Study of Culture, L.L. Langness reports:
“Virtually all of the early anthropologists seem to have believed in racial determinism, however implicit rather than explicit it may have been in their work. The effect of this belief was on the one hand to keep them from seeing the limitations of their evolutionary theory and on the other to let them ignore questions they might well have had to ask had they not assumed racial superiority.”
During the nineteenth and part of the twentieth century, one of the models for biological evolution was the Great Chain of Being which envisioned evolution as progressing from simple to complex in a hierarchical fashion with humans—Homo sapiens—as the pinnacle of evolution. Thus, the model for cultural evolution followed this same hierarchical model from simple hunting and gatherer cultures to the complex Christian civilization of England and the United States. In a similar fashion, languages and religions, as an integral part of culture, were arrayed from simple to complex, from primitive to modern.
In the twentieth century, with a greater understanding of biological evolution brought about by advances in genetics, the idea that evolution had a particular direction was largely abandoned. Evolution was no longer viewed as a progression, but as a complex web. Similarly, the ideas of stages of cultural evolution, such as those advocated by Morgan, were also abandoned. This does not mean, however, that the basic idea of cultural evolution has been declared invalid. Marvin Harris writes:
“No one has ever denied that cultures evolve in the sense that sociocultural systems undergo cumulative changes roughly analogous to those which eventuate in speciation or stellar and galactic transformations. The point at issue has always been the nature of the process of cultural change.”
In his book The Threshold of Civilization: An Experiment in Prehistory, archaeologist Walter Fairservis writes:
“Cultures are adaptive mechanisms, and their differences are not because of their stage of development in the direction towards civilization, but are rather a mark of their success in adaptation to their special physical, social, and cultural circumstances.”
Daniel Lieberman, in his book The Story of the Human Body: Evolution, Health, and Disease, writes:
“Human cultural creativity, once unleashed, has been an unstoppable engine of accelerating evolutionary change. Like genes, cultures evolve. But, unlike genes, culture evolves through different processes that make cultural evolution a far more powerful and rapid force than natural selection.”
In her chapter in Hunter-Gatherer Archaeology as Historical Process, Anna Marie Prentiss writes:
“Cultural evolution can be understood in Darwinian terms most simply because humans inherit (by learning, imitation, and the like) and act on cultural information. That information can form the basis for strategies allowing them to pursue food, learn resource configurations on landscapes, and compete with one another socially.”
In biological evolution, inheritance is passed down through genes, but in cultural evolution inheritance is through learning. In his essay on human evolution in The Epic of Evolution: Science and Religion in Dialogue, Francisco Ayala reports:
“Biological inheritance is based on the transmission of genetic information in humans very much the same as in other sexually reproducing organisms. But cultural inheritance is distinctly human, based on transmission of information by a teaching and learning process, which is, in principle, independent of biological parentage. Cultural inheritance makes possible the cumulative transmission of experience from generation to generation.”
Thus, we see culture features such as language, religion, tool-making, and marriage customs being passed down from generation to generation. However, as with biological evolution, replication is neither complete nor accurate and mutation takes the form of innovation and/or diffusion. Over time, some features are lost, new features are acquired, and some features are modified. Philosopher Daniel Dennett, in his book Darwin’s Dangerous Idea: Evolution and the Meaning of Life, writes:
“There is no denying that there is cultural evolution, in the Darwin-neutral sense that cultures change over time, accumulating and losing features, while also maintaining features from earlier ages.”
Does Culture Influence Biological Evolution?
Biological evolution and cultural evolution are closely intertwined. The human brain and mind coevolved with culture to provide humans with newer and more flexible ways of adapting to environmental changes. Donald Johanson and Blake Edgar, in their book From Lucy to Language, write:
“Once our ancestors began to develop a dependence on culture for survival, however, a new layer was added to human evolution.”
Donald Johanson and Blake Edgar also write:
“Human evolution is an intriguing interplay of biological evolution and cultural evolution.”
Francisco Ayala puts it this way:
“The advent of cultural heredity ushered in cultural evolution, which transcends biological evolution.”
The environment includes not only the natural ecology in which a group resides, but also its sociocultural milieu. In his book Before the Dawn: Recovering the Lost History of Our Ancestors, Nicholas Wade reports:
“Though evolution through natural selection depends on random processes, it is shaped by the environment in which each species struggles to survive.”
Nicholas Wade goes on to say:
“So to the extent that people have shaped their own society, they have determined the conditions of their evolution.”
In other words, culture is one of the environmental factors which can influence biological evolution through natural selection.
Some researchers feel that biological and cultural evolution are so closely intertwined that the term biocultural evolution may be a better description of the process. In his essay in The Epic of Evolution: Science and Religion in Dialogue, Philip Hefner writes:
“There is no dualism between culture and nature, except perhaps at the level of surface appearance—that is why we speak of biocultural evolution.”
Culture has also been the driving force behind the biological evolution of some human features. In his book The Story of the Human Body: Evolution, Health, and Disease, Daniel Lieberman provides one example:
“Sometimes cultural innovations drive natural selection on the body. A beautifully studied example is the ability to digest milk sugar as an adult (lactase persistence), which evolved independently in Africa, the Middle East, and Europe among people who consumed animal milk.”
Most humans today are unable to digest lactose after about five years of age. During digestion, lactose is broken down by the enzyme lactases into two simple sugars. After the age of five, the gene that regulates the digestion of milk turns off. In his book Ancestors in Our Genome: The New Science of Human Evolution, Eugene Harris writes:
“However, in some populations, the gene is not turned off and continues to produce lactase through adulthood.”
In cattle- herding people, milk can be an important food source and thus those people who are lactose tolerant as adults have an evolutionary advantage. Nicholas Wade reports:
“The genetic change evolved some 6,000 years ago among cattle herders of northern Europe and later among peoples of Africa and the Near East who took up pastoralism.”
An earlier example can be seen in cooking, which is a cultural innovation in the preparation of food. In his book Lone Survivors: How We Came to be the Only Humans on Earth, Chris Stringer writes:
“Once cooking became central to human life, it would have influenced our evolution, leading to changes in digestion, gut size and function, tooth and jaw size, and the muscles for mastication.”
In his book Nature via Nurture: Genes, Experience, and What Makes Us Human, Matt Ridley reports:
“At around 1.9 million years ago the teeth of human ancestors shrank at the same time as the body size of females grew. This indicates a better diet, more easily digested, which in turn sounds like cooking.”
Human Origins
Human Origins: The Mind
Human Origins: The Large Brain
Human Origins: The Human Hand
Human Origins: Bipedalism
Human Origins: Sexual Selection
Ancient Africa: Early Homo Sapiens at Pinnacle Point
Ancient Humans: A Short Overview of Homo Ergaster
Ancient Africa: A Short Overview of Homo Habilis