In their book Darwinism Evolving, David J. Depew and Bruce H. Weber make the interesting point that pre-Darwinian notions did not come to an abrupt halt with the advent of Darwin’s theory. Instead, they often became repackaged in superficially Darwinian terms.
That certainly applies to notions of adaptation in nature and human society. Before Darwin, most people regarded nature as the creation of a benign God. Of course it must be adaptive, from top to bottom! Human society must also be part of God’s plan, however inscrutable. As the Anglican Bishop Joseph Butler (1692-1752) put it, “It is as manifest that we were made for society and to promote the happiness of it, as that we were intended to take care of our own life and health and private good.”
Against this background, the original problem identified by Darwin and his partial solution (see T&R II) must have been disorienting. He was suggesting that adaptations might be restricted to individual organisms and that society might merely reflect their conflicts of interest. His partial solution meant that adaptations might exist above the level of individual organisms, but only if special conditions are met. In modern terms, adaptation at level x of the biological hierarchy requires a corresponding process of selection at the same level and tends to be undermined by selection at lower levels.
After Darwin, many biologists continued to assume that adaptations evolve at all levels — for the good of the individual, group, species, or ecosystem — without requiring special conditions. Social theorists continued to portray human society as like a single organism in the functional integration of its parts. When the problem identified by Darwin was acknowledged, it was common to assume that higher-level selection easily trumped lower-level selection. Today, these assumptions are labeled naïve group selectionism.
Naïve group selectionism is not dead. If you think that diseases evolve to avoid killing their hosts, that animals evolve to manage their population size, that ecosystems evolve to efficiently recycle nutrients, that nature left undisturbed achieves a harmonious balance, that earth’s entire biota qualifies as a single organism (the Gaia hypothesis), or that human society can be compared to a single organism, including technology leading to a single global brain, then you are a naïve group selectionist. You might be right, but you are not paying sufficient attention to Darwin’s sobering message that special conditions are required.
Everyone who teaches evolution knows that a large fraction of students start out as naïve group selectionists who are likely to utter phrases such as “for the good of the species” unbidden — even as the wrong answer on the final exam. There is something about adaptation above the level of the individual that just seems right, even when your teacher tells you it’s wrong.
A few biologists who followed in Darwin’s footsteps were not naïve, especially the three founders of population genetics theory, Ronald Fisher, J.B.S. Haldane, and Sewall Wright. Like Darwin, they had a lot on their minds. In their effort to place all aspects of evolutionary theory on a mathematical foundation, group selection was just one problem among many. Nevertheless, each clearly recognized that most social adaptations are locally disadvantageous. Either they pass out of existence, or they evolve on the strength of a selective advantage at a larger scale. Fisher, Haldane and Wright sketched a few models to illustrate the point but group selection did not occupy center stage and mathematical models were a foreign language to most biologists in any case.
To illustrate the influence of naïve group selectionism in the middle of the 20th century, here is the final paragraph of the most influential ecology textbook of the period, Principles of Animal Ecology (1949), authored by W.C. Allee, A.E. Emerson, O. Park, T. Park, and K.T. Schmidt, affectionately known as the great AEPPS.
The probability of survival of individual living things, or of populations, increases with the degree to which they harmoniously adjust themselves to each other and their environment. This principle is basic to the concept of the balance of nature, orders the subject matter of ecology and evolution, underlies organismic and developmental biology, and is the foundation for all sociology.
This passage, and the whole textbook, is suffused with the notion that nature evolves to be adaptive from top to bottom.
Enter George C. Williams, a tall man with the craggy features of Abe Lincoln or the statues on Easter Island. He was not mathematically trained but had learned the lessons of population genetics as a graduate student at the University of California at Berkeley before accepting a postdoctoral position at the University of Chicago in the late 1950′s. There he attended a seminar by Alfred Emerson, one of the great AEPPS, a termite biologist who regarded all of nature as like a termite colony. As George recalls the event, “if this was evolutionary biology, then I wanted to do something else — like car insurance.” George left the lecture muttering “Something must be done…”
A great reckoning was about to take place.
To be continued.