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The creative PNAS study that Razib pointed out the other day is out, and I’ve read it. It comes from two biologists at Stanford, Deborah Rogers and Paul Ehrlich, who studied the canoe design of 10 Polynesian groupsPolynesian Canoe and one Fijian group for functionality and symbolism. The paper, “Natural selection and cultural rates of change,” is open access, so please download a copy and read what the authors have to say first hand. They decided on these Oceanic cultures because they were colonized by one cultural group that radiated and became relatively isolated from one another. In other words, little outside influence, or noise, from other cultures has theoretically impacted Oceanic canoe design.

They find that functionality (traits that affect whether or not the occupants of the canoe will survive or not) changes very little, whereas symbolism in canoe design (such as aesthetic, spiritual, and decorative) changes much faster. From this observation, they conclude that “cultural change, like genetic evolution, can follow theoretically derived patterns,” and that natural selection is the driving force behind the evolution of cultural traits. The authors rationalize boats are being selected naturally through a quote from the French philosopher Alain,

“Every boat is copied from another boat… Let’s reason as follows in the manner of Darwin. It is clear that a very badly made boat will end up at the bottom after one or two voyages and thus never be copied… One could then say, with complete rigor, that it is the sea herself who fashions the boats, choosing those which function and destroying the others.”

This quote doesn’t make much sense to me. It sure is a simplified analogy… one that is supposed to help us digest and reduce… But I’m left a bit confused on how the authors found evidence of natural selection out observing intelligent boat design. Unlike boat designers, who learn and modify boat design based upon past experiences, natural selection does not operat with conscious understanding of trial and error. Natural selection in nature is independent. Boat design is not independent. Boat designers can go study past designs, learn from their mistakes, and make modifications… So is not functional boat design just selection?

That’s one flaw I see in this paper, one that I haven’t really completely thought out. I do appreciate how the authors are one of the first, in my knowledge, to attempt to integrate how ‘cultural things’, such as items that serve a life or death purpose in everyday life, have a functional constraint. Often we’re taught that ‘cultural things’ are arbitrary but we know we want our things to work, and we’ve will always design them to work better.

I’ll leave you with words from, Nina Jablonski, an anthropologist that I really respect and whose work I appreciate immensely. She christened this paper as, “one of the most significant papers to be written in anthropology in the last 20 years.” Man, that’s a pretty amazing endorsement to have, but just cause Jablonski casted her vote doesn’t mean I’m sold, nor does this make it into the trophy cabinet for classical anthropology papers.

    Rogers, D.S., Ehrlich, P.R. (2008). Natural selection and cultural rates of change. Proceedings of the National Academy of Sciences DOI: 10.1073/pnas.0711802105