Since he began writing a column for Natural History, Stephen Jay Gould has distinguished himself as one of America’s foremost interpreters of Darwinian evolution for both the scientist and the general reader. He has a knack for making recent scientific findings accessible and interesting without condescending to the reader, often by fixating on one component of nature such as the panda’s thumb or the taxonomy of wasps and using it to illustrate some principle of evolution. Full House: The Spread of Excellence from Plato to Darwin was written in conjunction with Wonderful Life (1989) to persuade his readership to reconsider their conception of humanity as the crowning achievement of evolution. Gould posits a complete reversal of this anthropocentric view in which animals adapt over time into more complex, superior forms. Instead, he claims evolution is fundamentally passive and does not progress at all.
To help readers understand the basis of his theories, Gould returns again and again to Charles Darwin’s Origin of Species, much of which sets out to prove three basic principles, which Gould lists as follows:
1. All organisms tend to produce more offspring than can possibly survive.
2. Offspring vary among themselves, and are not carbon copies of an immutable type.
3. At least some of this variation is passed down by inheritance to future generations.
From these inferences, Darwin can conclude that “survivors will tend to be those individuals with variations that are fortuitously best suited to changing local environments.” Thus woolly mammoths are hairy because hair best suits the cold Siberian climate. Interestingly, Gould points out how Darwin disliked the word “evolution,” since it emphasized progress. The word “adaptation” better captures the passive nature of species changeover.
To modify the contemporary perception of evolution, Gould focusses on variations within entire systems which can be graphed out statistically. Gould’s graphs show that any consideration of an average life form ignores the wide assortment of variations surrounding it. After giving his lay readers a crash course in statistics, Gould then provides multiple examples of wrong-headed “ladders” needing to be replaced with the broader picture of a full house of variation, a methodology which applies equally well to help analyze changes in baseball, cancer prognoses, and trapeze artistry, as well as to the evolution of different species. His examples of complex organisms that inhabit the earth in the late twentieth century—humans, horses—are only incidental offshoots of a gigantic “bush” that could just as easily have not produced humans.
Gould painstakingly teaches the reader his conceptual apparatus. For example, a bell curve suggests an even distribution of something, like a selection of graded assignments that can be “curved” to cover all grades equally. In nature, however, distributions are more often skewed in one direction with a “wall” forming one limit of possibility and a “tale” stretching beyond the frame of the graph. Given the assumption that life began in primordial soup billions of years ago as single-celled organisms, life had no way to evolve but toward multicellular creatures. The fact that life was just beginning formed one “wall” of variation while more complex multicellular organisms evolved along the opposite side of the graph. Any time some activity produces a variety of results, be it biological or cultural, a graph depicting the contraction and expansion of that variation provides a better picture of reality than a study of some average arbitrarily chosen within it. Thus Gould debunks the idea of a Platonic ideal man since it leads people to ignore all the variant humans that nature randomly produces.
To a large extent, Gould reports his findings in opposition to any essentialist view of the world. In keeping with the search for some ideal form, scientists in the past have looked for average samples which make all variations mere aberrations of nature. Thus, classical thinkers thought that there was just one sex, male, and the female sex was a degraded variation of the ideal male. More recently, people still tend to think that homosexuality is an aberration on the “ideal” heterosexual impulse, whereas nature produces multiple forms of sexuality. This search for the fallacious average or ideal takes the statistical form of tracing means, modes, and medians plotted along the rates of distribution. Gould uses his personal experience of learning that he was likely to die of cancer in eight months to show that all such averages can easily mislead scientists or doctors when they fail to take in account the entire system of variation....
(The entire section is 1963 words.)