To Understand Everything, Understand Evolution

The incredible power of the evolutionary framework.

Posted Mar 03, 2017

Wikimedia Commons
Source: Wikimedia Commons

The fact that “nothing in biology makes any sense except in the light of evolution” [1], noted 44 years ago by Theodosius Dobzhansky, is as true now as ever. If we want to understand the nature of organisms, and why they are the way they are, evolutionary theory is the only game in town and we’d be hopelessly lost without it.  Thank you, Darwin, for showing us the light.

In truth, however, evolutionary theory is not just as relevant as ever, it's more important than ever. In the decades since Darwin and Dobzhansky, it’s become increasingly obvious that it’s not just biology in general that makes sense only in light of evolution. There are also two very important and specific biologically-based aspects of the human experience, that have traditionally been considered off-limits to evolutionary analyses, that also make sense only in this light.

The first of these aspects is human psychology: If we want to understand the genetically-encoded psychological devices that compose the mind of humans (or any species), our only hope is to discover the functions for which natural selection (or sexual selection, or kin selection) designed these devices [2]. Our minds were built primarily by and for the hunter-gatherer environments of our evolutionary ancestors, and are composed mainly of information-processing mechanisms designed to enable survival and reproduction in these environments. By acknowledging this reality, we put ourselves in the best possible position to understand and predict human thought, emotion, and behaviour in modern environments. (For more on evolution’s fundamental importance to psychology, see my essay, “All Psychology is Evolutionary Psychology”).   

The second of these aspects is human culture. Culture is 100% biological, in the sense of being 100% generated by biologically-evolved psychological mechanisms. However, culture itself can evolve by a process that is distinct from biological evolution [3]. Compared to biological evolution, cultural evolution is much less dependent on changes in gene frequencies and can therefore occur much faster. And cultural practices, just like biological and psychological traits, are incomprehensible unless we understand their evolutionary origins and raisons d'être. If we want to know whether a particular moral rule or cultural institution, for example, has in the past fulfilled some useful social function—such as advantaging a society in competition with other societies—a cultural evolutionary analysis is our only way to find out. (For more on cultural evolution, and its relevance to our contemporary political climate, see my essay, “Why Progressive Humanist Values Will Ultimately Prevail”.)

The evolutionary framework, then, has proven itself to be fundamental and indispensable for explaining all biologically-based phenomena, including psychology and culture. Even more impressively, however, we may have only just begun to appreciate the incredible power of this framework. Physicists like Lee Smolin [4] have speculated that the characteristics of our universe itself may be best explained by a theory of cosmological natural selection, which regards universes as self-replicating entities, competing for representation in a population of other universes (i.e., a multiverse). (For more on this theory, see my essay, “Could Cosmological Natural Selection Assign a Function to Life?”). Although vastly more speculative than theories of biological and cultural evolution, this theory raises an intriguing possibility: Someday, the phrase “nothing in physics makes sense except in the light of evolution” may not seem extraordinary at all.

A version of this article will be published at This View of Life.


Copyright Michael E. Price 2017. All rights reserved.

References

1. Dobzhansky, T. (1973). Nothing in biology makes any sense except in the light of evolution. American Biology Teacher 35: 125-29.

2. Tooby, J. & Cosmides, L. (1992). The psychological foundations of culture. In J. Barkow, L. Cosmides, & J. Tooby (Eds.), The Adapted Mind: Evolutionary Psychology and the Generation of Culture. Oxford University Press.

3. Boyd, R., & Richerson, P. J. (1988). Culture and the Evolutionary Process. University of Chicago Press.

4. Smolin, L. (1997). The Life of the Cosmos. Oxford University Press.