Evolutionary Theory

Evolutionary Theory in Archaeology

In their introductory chapter, Barton And Clark question the applicability of evolutionary theory into archaeology. In the 19^th century thought there was a tendency towards unilinear change. Darwin and Wallace proposed an alternative explanation to why and how life changes. Darwinian theory came into archaeology in 1970’s with the contributions of Dunnel and Rindos. It was a trial to take a scientific approach to past human societies and social change.  the evolutionary theory is a theory of change. culture changes from  the different persistences of different behaviors over time. this persistence, according to the authors, can be explained throught the application of a limited number of universal processes- that remain unexplained through the chapter-.

Then the authors explain behavior as the interacting phenotype and environment-so evolutionary theory may apply to behavioral study. Both behavioral and biological systems cause  evolutionary processes. The maintain temporal continuityand tend to expand over time. there are some misconceptions presented about evolutionar theory in the chapter: one of them is the perception of evolutionary theory as dealing only with the interaction between humans and natural environment.another misconception is that evolutionary theory is a revived social Darwinism. Neo evolutionarism, according to the authors, is not about the “survival of the fittest”, nor does it claim that evolution is equal to selection. And it is not about unilinear progression. There are some exceptions to the rule, like maladaptive strategies, uniqueness of culture. The authors cluster the whole concept of culture and cultural transmission in this little section of exceptions to the rule (in fact I have always considered the human being as an exception to nature, but I digress), and underestimate the importance of intent, inventiveness and innovation. This paragraph will be criticized later. on the other hand, it is stated that evolutionary processes did not operate directly on the material culture that form the archaeological record, but on the behaviors that originally produced it. I believe that this sentence is fautive: the material culture as archaeological remains, reflect behavior. Otherwise it would be meaningless to excavate. The authors also fall short of giving satisfactory explanations about how this approach will be applied on complex societies – or, is Neo-Darwinism really a study of hunter-gatherers?-, the un-randomness of certain human behavior- like social learning. The only explanatory sentence is that:” non-genetic transmission of behavior is much more varied and flexible”. If I had read this introductory chapter in the intention of reading the whole book, I would surely change my idea.

In his philospohical chapter about evolutionary theory, Dunnel successfully explains it and compares its application on biology and in archaeology. The author states that, anthough the Evolutionary theory is a scientific theory about variation, the traditional archaeological description is modal, focusing on trends. If we were to apply the Darwinian theory into archaeology, we should first change our archaeological methods.

Materialsim, is about a quantitative view of temporal relations. Application of evolutionary theory requires units, on which selection can act but on the other hand, selection occurs on a continuous basis. The materialist paradox requires us to distinguish units on two dimensions: the location of the unit, and the size of the unit. The author criticizes the Marks-Staski model on evolution in terms of units. Species are taken as “an individual” as given fact. Fror Darwin, species can be both theoretical and epiphenomenal, but species originate in the process of observation, and are empirical. Another study criticized i Durham’s book called “coevolution”. Durham develops a theory of cultural evolution on a biological model. He states that cultural evolution is parallel with biological evolution. Because Durham doesn’t clarify the units, there are much ambiguous statements in the book. he talks about opposition(cultural change working against inclusive fitness) and imposition (manipulation by another group), but imposition requires two groups. So the unit must be the group as the individual- this makes Durham biased.

According to Dunnell, the lack of consensus on units in biology is not so important because evolutionary biologists do agree on the charateristics that an evolutionary-individual must have- reproductive, functional, rapidly responding-. So the scale is an empirical question. In archaeology, however, evolutionary individual in the human lineage is not different from the other social animals until the rise of complex societies. But then, there is a shift in the unit. In complex societies, groups are functionally differentiated organisms that constitute “the individual”

Another question is what kinds of units can be identified in the archaeological record and by what means can they be related to the unit requirements of evolutionary theory. There is little cultural data that can be collected from the remains of the individual organism. Most of the data comes from a number of individuals over time. On the other hand, while the biologic inheritance is constrained by genetics, the cultural transmission is done via several parents.

Then Dunnell points at some methodological problems in archaeology. The theorietical units are defined as collections of components,  while the emprircal units, are defined as manifestations of phases- or components. Another problem is the understanding of the “site”. It is a theoretical construct. The scale here should again change, because traditionally common sense is used in defining it rather than theory. Adopting concepts from biology or anthropology will not contribute to archaeology as long as we use the old methods of observation. An application of evolutionary theory, should begin with the set of units specified.

O’Brien and Holland write about the selection based archaeology, claiming that it is a powerful means of explaining variation. Evolutionary archaeology claims that, humans like any other organisms, are directly affected by selection and the material record reflects the effects of selection. Evolutionarists believe that, humans are not immune from the selection processes by being “culture bearing” animals. the basic premises of evolutionary archaeology are stated as,

-Objects observed in the archaeological record are fossilized remnants of human phenotypes. These fossilized remains can contribute as much info about human fitness and adaptation as can any biological feature;

-The archaeological record is biased;

-Intention’s role on social evolution is trivial.

Here I would like to quote one paragraph from the reading:

“Many early aviators must have leapt from cliffs, propelled by hopeful inventions and the intent of flying. Ultimately it was the ability to overcome gravity-not intent- that determined which aviators survived to pass their genes and inspiration to the others”. This sentence must be an unhappy joke. First of all, it completely ignores the existence of deliberate innovation. This is one of the aspects that differentiates humans from other animals. Second, human beings did not evolve in order to fly (we still don’t have wings and feathers, unfortunately), they did a deliberate invention- the plane, a tool which helps them to go flying. Third, one doesn’t need to bear the noble genes of Wright brothers in order to build a plane and fly: the technology of an airplane was fastly shared throughout the world. This sole statement shows that the authors completely forgot about social transformation, the spill of information among individuals and even among cultures.

In his very informative essay, Shennan sheds some light on those neglected aspects.the author clarifies that, there are two tenets on social evolution. First, natural selection on people’s survival and reproduction can occur through selection on their cultural traditions, not simply on their genes via their genetically inherited dispositions. Second, processes of cultural selection can also operate as a result of conscious and unconscious decision-making. This inheritance system that the author calls as the “meme” operates through social learning. But according to the author, this does not make cultural transmission not Darwinian, because both genetic and cultural inheritance are specific info transfers that permit variation through time.

Humans are capable to alter the effects of natural selection by decision-making. Cultural traditions, are also complex biases that can alter selection. But when we talk about inheritance, there is both genetic inheritance  and cultural inheritance transmitted. The routes of transmission are, through sexual reproduction (DNA’S), and one-to-one, one-to-many, many-to-one versions of cultural transmission.  The author also points at the difference between innovations and mutations. Mutation is rare and random. Innovations are also transmitted from generation to generation but there may be experimentation and improvement later(just like in the aircraft technology). And there is of course, intentionality.

There are three modes of transmission that the author talks about. one is Directly Biased Transmission, where people change their way of doing things as a result of comparing their own method with that of someone else. In the Indirectly Biased Transmission, the individual adopts the cultural attribute of  another individual because that individual appears to be more “succesful” no matter if the attribute concerned effects his success. Another is the Conformist Transmission: people do what most of the other people are doing.

There are some advantages and disadvantages of social transmission. Social learning is more beneficial that individual trial and error method because it requires less time and is less painstaking. On the other hand, by learning, the individual can also make further innovations on the transmission and thus the transmitted info will evolve faster. On the other hand, social learning can also lead to conformism.