Natural Selection and Cultural Rates of Change: A Summary

the following is a write up on 'Natural Selection and Cultural Rates of Change: A Summary' by Rini Thomas

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This paper is a summary of the essay ‘Natural Selection and Cultural Rates of Change’ by Deborah S, Rogers and Paul R. Ehrlich from the Department of Biological Sciences, Stanford University and was published by the National Academy of Sciences. The essay focuses on cultural evolution. It claims that a meaningful theory is not possible as it is understood that human beliefs and behaviours do not have patterns that can be predictable. But in the development of societies it is believed that patterns in cultural evolution do occur. This excerpt analyses how two sets of related cultural traits, one that is tested against the environment and the other not. The final outcome is how they both evolve at different rates among the same populous. Ultimately the analysis boils down to a point which indicates how cultural change like that of genetic evolution can follow theoretically derived patterns.

As stated earlier, scientific theory of cultural evolution is not possible as critiques of cultural evolution from the science domain object that analogies with genetic evolution do not hold. They also argue that culture is altered by a series of historical events. The way biologists have developed theoretical models to understand patterns in genetic evolution; certain theorists have tried it in cultural evolution as well. It refers to the change in the behaviour affected by transmission and innovation. But it does not still answer the question if it helps in comprehending the patterns through theoretical models. The next argument is, cultural characteristics that are tested against the environment evolve faster than that of characteristics that are not tested. Several examples are given to prove the same. But is it possible that this can be applied to cultural evolution? Human cultural groups, like genetic demes, live in different environments and have a high rate of within group exchange of traits but also have the potential for some exchange with other groups through migration and cultural borrowing.

In order to understand the traits of cultural evolution ten Polynesian island groups were studied. Polynesia is a useful model system for looking at cultural development because this region was originally colonized by one cultural group and then it set of to related islands. The traits were divided into functional and symbolic traits and through canoe designs it was analysed. The final outcome shows that the environmental characteristics are faster than the other ones and this is clearly depicted in Figure 1, 2 and 3. The results indicate that functional traits have changed at a slower rate than the symbolic traits. These results suggest that cultural changes are evolutionary and it happens through theoretical based patterns.

The methods that were chosen for this study; 1. Presence/Absence Data Matrix, 2. Jaccard Distance Matrices, 3. Mantel Test, 4. Sign Test, and 5. Wilcoxon Signed Ranks Randomization. These methods help in finding out the results that prove the thesis statement of the essay. This proves how cultural change like that of genetic evolution can follow theoretically derived patterns.

Reference

http://www.jstor.org/stable/25461249 Vol. 105, No. 9 (March 4, 2008) pp 3416 – 3420