When Charles Darwin published On the Origin of Species by Means of Natural Selection, or the Preservation of Favoured Races in the Struggle for Life in 1859, he eloquently summarized his theory, in the last paragraph of that work, as follows:
These laws [whose actions have resulted in the biotic
World we see today], taken in the largest sense, being
Growth with Reproduction; Inheritance which is almost
Implied by reproduction; variability from the indirect and direct action of the external conditions of life, and from use and disuse; a Ratio of Increase so high as to lead to a Struggle for Life, and as a consequence to Natural Selection, entailing Divergence of Character and Extinction of less-improved forms (Darwin 1859: 489-490).
Darwin’s theory was incomplete in that he was unable to specify a mechanism for inheritance. This was supplied by Mendel in 1865, a contribution ignored until his work was replicated, then rediscovered, in 1900. The resulting hybrid was later joined with population genetics and reconciled with findings from paleontology to create the ‘modern synthesis’, the standard version of evolutionary biology in the mid-1900s.
Bioanthropologists, of course, used the concepts in the synthesis to explain hominoid biological evolution, but cultural anthropologists - from whom most archaeologists took their lead - were for the most part content to consider that ‘cultural evolution’ as characterized above represented the valid extent to which biologically inspired thinking could be brought to bear on their subject.
This began to change only in the 1980s. Although ‘new archaeologists’ paid lip service to evolutionary theory in the 1960s, Robert Dunnell was a key figure in insisting that archaeologists had serious work to do in realizing the potential of evolutionary theory in archaeology, for example, in carefully considering how an analogy could be built up between culture change and genetic change, what the units of selection ought to be in the study of culture change, and which units were under selection and which might be neutral with respect to selection. He developed an approach, usually called selectionism, which considered human technology to be part of the human phenotype. (This approach is sometimes called ‘evolutionary archaeology’, but the author considers this somewhat imperious, since there are other ways to apply evolutionary logic in archaeology; therefore, the narrower term is used here.) Selectionists characterize the replicative success of variant technologies through time, for example, by graphing the relative frequency of variants in an archaeological sequence. They propose various guidelines to determine from the shapes of these graphs whether variants were under selection - or closely correlated with something that was under selection - or whether the observed changes through time were only what would be expected under drift. Drift is a population-level process that is random, meaning that variants increase or decrease by chance alone. Variants whose behaviors appeared to be random were defined as stylistic (neutral). If variants appeared to be under selection, then an effort was made to identify the selection pressures causing that change.
World History
