David Wilson offers a thumbnail sketch of the current state of scientific knowledge about cultural evolution in an interesting response to Jerry Coyne’s tepid review of his latest book: The Neighborhood Project: Using Evolution to Improve My City, One Block at a Time.

1. Darwin’s theory of evolution originally said nothing about genetics. It was framed in terms of heritability, which is a resemblance between parents and offspring. Any proximate mechanism that results in heritable variation enables organisms to adapt to their environments.

2. Genetics is the first inheritance system to be worked out in detail–so much detail that many people, professional evolutionists included, reflexively equate evolution with genetic evolution. There is no conceptual warrant for this assumption, however.

3. There is a long history of theorizing and research on evolution as a substrate-neutral process, based on the three fundamental ingredients of variation, selection, and heritability. What “substrate-neutral” means is that there can be many proximate mechanisms underlying heritable variation. Genetic algorithms in computer science provide an example.

4. An excellent recent book on this topic is Evolution in Four Dimensions, by Eva Jablonka and Marion Lamb. In clear language that any reader with sufficient interest can understand, they show how epigenetic mechanisms, learning, and symbolic thought count as inheritance systems, which interact with each other and with genetic inheritance. They also recount the history of why genetic inheritance became so dominant for the study of evolution that many people reflexively equate evolution with genetic evolution.

5. Non-genetic inheritance systems evolved by genetic evolution and have complex architectures insuring that the outcome of evolution is genetically adaptive, on average. For that matter, genetic inheritance has a complex architecture that evolved by genetic evolution, a topic that is often called “the evolution of evolvability” (type this phrase into Google Scholar for more).

6. The vertebrate immune system provides a model for understanding other inheritance systems that evolved by genetic evolution. On one hand, it is elaborately genetically innate, as anyone who has tried to learn immunology knows. On the other hand, it is elaborately open-ended, thanks to the capacity to generate app. 100 million antibodies and select those that successfully bind to antigens. We should be thinking of our capacity for open-ended individual and cultural change as like the immune system, which is a major theme of The Neighborhood Project and some of my academic articles.

7. B.F. Skinner described operant conditioning as a product of genetic evolution and itself an evolutionary process (see his classic paper titled “Selection by Consequences“). This part of behaviorism was on the right track, however much the tradition failed in other respects. Bizarrely (in retrospect), the brand of evolutionary psychology associated with Leda Cosmides and John Tooby set itself apart from the open-ended capacity for change associated with behaviorism. Creating a broader vision of evolutionary psychology is part of the serious work attempted in The Neighborhood Project and my related academic work.

8. The study of human cultural change as an evolutionary process has a long history that dates back to before Darwin–linguistic phylogenies existed before biological phylogenies. Some of the early conceptions were mistaken in retrospect, such as cultural evolution as a linear progression from “savages” to “civilization”. Dawkins’ concept of memes got some things right but other things wrong. The current state of play is represented by books such as the aforementioned Evolution in Four Dimensions, Not By Genes Alone: How Culture Transformed Human Evolution (by Pete Richerson and Rob Boyd), War and Peace and War (by Peter Turchin), and Sense and Nonsense: Evolutionary Perspectives on Human Behavior (by Kevin Laland and Gillian Brown). Although much remains to be discovered, the consensus view is that genes and culture have been co-evolving for a long time, so that the study of humans must be based on a firm foundation of biocultural evolution.

9. While individual learning and a degree of cross-generational social transmission takes place in many species, the human capacity for symbolic thought places us in a league of our own as far as cultural evolution is concerned. Symbolic systems have the same kind of combinatorial diversity as genetic systems–and every “symbotype” has a corresponding phenotype. The analogy between genetic evolution and cultural evolution is anything but superficial.

10. The subject of cultural evolution intersects with the subject of group selection in a number of ways. A major evolutionary transition was probably required for our capacity for symbolic thought to evolve in the first place. Given our current capacity, cultural evolution is a multilevel process, no less than genetic evolution. In other words, a cultural trait can spread by virtue of benefitting some individuals compared to others within groups, or by virtue of benefiting whole groups, compared to other groups. It can also spread without benefitting human individuals or groups, a legitimate possibility suggested by authors such as Richard Dawkins and Daniel Dennett. Most authors who contribute to the academic literature on cultural evolution accord a strong role for cultural group selection.

Source.

David Wilson is the Author of The Neighborhood Project: Using Evolution to Improve My City, One Block at a Time.

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