Convergent Evolution and Multiple Discovery

Posted on June 22, 2008 by Peter Turney

Convergent evolution is “the development of similar structures in distantly related organisms as a result of adapting to similar environments and/or strategies of life”. I’ve talked before about multiple independent simultaneous discovery and invention in science, technology, and art. I’ve mentioned that multiple discovery supports an evolutionary view of culture, but I haven’t really discussed why I believe this. The reason is that convergent evolution is the best explanation for multiple discovery.

Multiple invention in biology:

Multiple discovery in science:

Multiple invention in technology:

Multiple creation in art:

It is generally accepted that Darwinian evolution explains convergent evolution in biology. Darwinian evolution happens whenever we have three things: variation, heredity, and differential fitness. If different species are faced with similar environments, then it is not surprising that they often evolve similar mechanisms for survival in those environments.

However, there seems to be resistance to the view that Darwinian evolution explains convergent evolution in culture (e.g., science, technology, art). Perhaps this is because Darwinian evolution is often described as “random mutation plus selection”. We are reluctant to view human ingenuity as mere randomness, so we reject the application of Darwinian theory to culture. But Darwinian theory does not require randomness; it requires variation. The source of the variation can be random, but it is not necessary that it must be random.

Another objection to applying Darwinian evolutionary theory to cultural change is the idea that most multiple discoveries are due to copying. It is true that direct copying happens, and that the later discoverer/inventor/creator may sometimes be dishonest about copying, but there are many historical cases where copying appears unlikely. Note that direct copying is not incompatible with evolution. For example, bacteria copy plasmids from one another.

We know that biological evolution generally happens in many small increments. Perhaps we resist the theory of Darwinian cultural evolution because it often seems that technology (for example) proceeds in sudden jumps. However, a close study of the history of any particular technology invariably shows a series of small, incremental developments. The apparent jumps are an illusion, caused by the way technology is adopted.