What the late biologist George Price can teach us about the price of altruism.
Sunday, January 6, is the 44th anniversary of the death of someone whose life I think about a lot: evolutionary biologist George Price.
Price is perhaps most famous for his namesake Price equation, which takes many forms but is perhaps most easily understood in its “simple” form:
“It captured the essence of evolution by natural selection in one simple formula,” the science journalist Michael Regnier explains. “It describes how in a population of reproducing individuals, be they people, plants or self-replicating robots, any trait (z) that increases fitness (w) will increase in the population with each new generation; if a trait decreases fitness, it will decrease.”
Here “fitness” is meant in the technical, biological sense: the degree to which a trait improves the reproductive success of an organism.
You can find a blunter explanation in the 2007 horror movie WΔZ (which takes its name from the left half of the equation), in which a biologist played by Paul Kaye explains it to our heroes Melissa George and Stellan Skarsgård:
The Price equation is useful for describing natural selection in general, but it’s especially interesting in explaining a particularly puzzling biological phenomenon: altruism.
As early as Darwin, the existence of self-sacrificing organisms that are willing to give up their own lives, and their own ability to reproduce, for the sake of others, posed a puzzle for evolutionary theory. Regnier offers the example of worker ants, which “are sterile and so have literally zero fitness.” How do those continue to exist, if they, by design, cannot produce offspring sharing their traits?
In trying to