Discrete or Continuous?
We described different modes of subsistence and associated forms of social organization almost as if wholly discrete. While they do not form a smooth continuum, the distinctions are more like multimodel clusters than discrete kinds. For example, some primarily hunter-gatherers may cultivate a small patch of a basic food plant in a cleared patch, abandoning it to look after itself until they harvest it on their next return. All pastoralists utilize some plant foods which they may acquire by trade or cultivating small gardens. Members of horticultural, intensive agricultural, and even industrial societies eat some wild foods, and the latter may keep small gardens around their homes. This variability is also true of social organization. While no hunting and gathering society has been organized as a state and no state has subsisted exclusively on wild food, in between there is a fair amount of overlap. For example, horticultural and pastoral societies can be socially organized along kin-based tribal lines or as chiefdoms, and intensive agricultural societies can be socially organized based on chiefdoms or states.
Evolution
In the social as in the life sciences, ecological and evolutionary theories are closely linked. It is often forgotten, for example, that Julian Steward first discussed cultural ecology in a book titled Theory of Culture Change: The Methodology of Multilinear Evolution. Some degree of variability within a particular mode of subsistence and social organization as described above is inevitable, given that the different modes are related by common cultural descent from hunting and gathering which was the primordial mode of human subsistence. However, biologically, just as prokaryotic cells evolved from eukaryotic ones does not mean that prokaryotic cells did not persist, and that multicellular organisms evolved from unicellular ones does not mean that unicellular organisms did not persist; culturally, the fact that horticulture evolved (branched from) hunting and gathering, and that pastoralism evolved (branched from) horticulture, as they are believed to have done, does not mean that hunting and gathering and horticulture did not persist. Culture, like life itself, evolves by descent with modification in a ‘multilineal’ fashion, like a branching tree, rather than developing like a single organism does in a linear sequence of stages.
The Role of Ecology and History
Although there are others like drift (sampling error) and the laws of physics and chemistry, biological evolutionists emphasize that two forces largely explain the existing array of organisms - the forces of selection and the weight of history. Darwin called these ‘the conditions of existence’ and ‘the unity of type’. While the different modes of subsistence described are historically related, that is so only in a very general sense. In other words, culturally different modes of subsistence and forms of social organization are more like biological ‘guilds’ (organisms which occupy a similar niche and follow a similar way of life) than they are like biological ‘clades’ (all the descendants of a common ancestor). For example, we know with confidence that agriculture evolved independently in a number of different places in the world. Only archaeological research can reveal actual historical affinities.
What is the Mechanism of Cultural Adaptation?
The concept of adaptation is ubiquitous in cultural ecology and ecological and environmental archaeology. Different modes of subsistence are different modes of adaptation to the ecological environment. In biology, there is a mechanism explaining adaptation. At its most basic, the mechanism is Darwin’s natural selection, natural selection acting among alternative alleles or versions of a gene. But what is the mechanism of cultural adaptation? Many theorists across a wide variety of social sciences today think that cultural evolution is an analogous process (or an instance of the same general class of selection processes). The basic elements of an evolutionary process - transmission, variation, and selection - are the same except that cultural evolution is based on social learning or meme-based transmission rather than the gene-based. This theoretical perspective is very well-developed in archaeology where methods of classification originating in biology are increasingly used to understand the historical relationships among artifacts, for example.
Of course, there remain a variety of other theoretical perspectives. For example, just as developmental biologists prefer to begin the story of life with individual organisms growing and developing rather than with members of populations of adults differentially reproducing, many social scientists prefer to begin the story of culture with individuals learning and/or making rational choices, rather than with members of cultural populations being differentially transmitted by social learning. Similarly, just as some biologists prefer to emphasize the way that organisms construct their environments (niche construction) rather than how populations of them are structured by it, some social scientists prefer to emphasize how culture constructs nature rather than how it is structured by it. While these development versus evolution and construction versus structure ‘chick-en-and-egg’ problems have not been entirely resolved in either realm, it is likely that the alternative perspectives in either case will eventually be understood as being compatible. That, at least, is the assumption generally made by biologists.
Still other theorists are impressed with the overwhelming importance of rituals in human society. The ecologically oriented, however, have shown that even some very exotic rituals can be shown to be ecologically adaptive and some ritual-like behavior is known to occur among animals. There it generally serves the same kind of function as it does in humans, either inducing an emotional state which promotes conformity or testing the propensity of individuals to conform, prior to some group activity important for ecological reasons. More to the point here than these various theoretical debates, the evolutionary-ecological perspective implies that many principles of evolutionary ecology that are biological in origin can be applied to cultural ecology.
The Evolutionary Ecology of Culture
It is a general principle of foraging that low densities relative to resources favor eating (acquiring more resources), while high densities favor digesting (deriving more breakdown products from each such resource unit acquired). Cultures behave similarly. Even hunter-gatherers process food in various ways - use tools to cut off the most tender cuts of meat; chop, pound, and winnow plant foods; and cook many different kinds of foods. These are all methods of pre-digestion, suggesting that even hunter-gatherers experience resource pressures. Indeed, all techniques of cultivation used in horticulture and intensive agriculture, techniques such as irrigating and fertilizing, are methods of intensification, of deriving more resources from each land unit. On a larger scale, low densities favor growth while high densities favor motility in a colonizable environment, maintenance in a renewable one, and mutability (innovation) in one with environmental carrying capacity unutilized for historical reasons. While all cultures use all of these strategies to some degree, hunter-gatherers tend to emphasize motility, moving on when resources become depleted. Agricultural societies tend to emphasize maintenance, methods of storing and preserving food until at least the next harvest. Industrial societies tend to be very technologically innovative. Density dependence is only one kind of example; there are other evolutionary-ecological principles of potential relevance to cultural ecology and archaeology, principles such as scale, frequency, and heterogeneity-dependent selection.
Co-evolution
If culture and not genes only evolve in the human species, then the relationship between them is a coevolutinary one according to many theorists, that is, our genes and culture evolve in interaction with each other. Surprisingly, whether adaptation in any particular case is achieved genetically or culturally may not have made much difference for most of the history of our species because as long as transmission is from parents to offspring or at least among closely related kin, the results of the two are generally predicted to be similar. It is only with the coming of non-kin based social organization and ultimately dense populations, cities, schools, mass communications, etc. that genetic and cultural transmission and hence adaptation begin to diverge (think of modern difficulties in achieving ‘life-work balance’). More to the point here, however, it is believed that the relationship between human culture and the biology of other species has been a co-evolutionary one.
There are three basic modes of co-evolution -
Competition (--), cooperation or mutualism (++),
And antagonism (H—). The relationship between domesticated species and the cultural practices of domestication are generally thought to be mutualis-tic, that is, a relationship from which both parties benefit. There are characteristic changes which tend to take place in species under domestication. These include more docile personalities, a reduction in the size of weapons like horns, and a general loss or at least a reduction in the ability to defend themselves from predators and parasites, functions which we tend to assume. Once some of these have been achieved, sizes tend to increase again. While our relationship with domesticated species may largely be mutualistic, there is no doubt that our relationship with most species has been antagonistic, in particular one in which we benefit and they lose. The evidence is strong that we are in a period of mass extinction of species rivaled only by the half dozen or so mass extinctions of planetary history, but this time brought about by us, largely through habitat destruction. To be fair, we also remain the victims of a number of viral, bacterial, and protozoan parasites.
World History
