Unrivaled acumen, communitarian passion

The Richness of Life: The Essential Stephen Jay Gould. Edited by Steven Rose. W.W. Norton and Co., New York, 2007. ISBN: 978-0-393-06498-8. 654 pp. Hardcover, $35.

If the course of evolution were commanded by a superior intelligence or according to some species-centered notion of progress, humans might reasonably expect to be surrounded by the likes of Stephen Jay Gould. Before his death in 2002, Gould was a prolific and award-winning author, a distinguished member of the National Academy of Sciences, and Harvard professor of zoology and geology for more than thirty years. But informed laypersons know better than to take such brilliance for granted, thanks in large measure to Gould himself as seen in the new book The Richness of Life: The Essential Stephen Jay Gould.

After three billion years of unicellular ascendancy, then a mere five million years of Cambrian creativity, Gould argued, the last 500 million years of "variation on set anatomical themes can scarcely be read as a predictable, inexorable, or continuous trend toward progress or increasing complexity" (Rose 217). Natural selection, in fact, has never favored intricacy. Rugged, diverse, and highly adaptable, bacteria have long been and probably will always be the most successful life form on Earth. And what could be more random--more lucky or unlucky depending on your perspective--than death by mass extinction? Consider the fates of the diatoms (eukaryotic algae) and small, rat-sized mammals that lived 65 million years ago, just prior to the notorious asteroid impact off the Yucatan peninsula. Diatoms didn't survive because they were loved from above or because of their advanced biology. These single-celled players hit the Cretaceous lottery only because they had previously evolved a seasonal dormancy strategy. Nor were mammals in any way superior to the dinosaurs with which they had coexisted for 100 million years. Only their diminutive stature allowed them to persist and us to subsequently evolve. Complexity, intelligence, and consciousness, in other words, were begat by nothing more progressive or divine than dumb luck.

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But Gould was celebrated as well for his gritty confrontations with fellow intellectuals--zoologist Richard Dawkins and philosopher Daniel Dennett--most conspicuously. He pejoratively referred to them as "Darwinian fundamentalists" or "ultra-Darwinists" because of their supposed insistence upon interpreting every organismal attribute as an adaptation for reproductive success. Their "adaptionist program" dogmatically assumes natural selection to the exclusion of all other evolutionary mechanisms.

With Dawkins, Gould took issue on two fronts. First, the idea that organisms amounted to little more than passive vessels puppeted by genes struggling for reproductive advantage represents the pinnacle of adaptionism. The "selfish gene" theory, Gould scolded, was "a logically flawed and basically foolish caricature of Darwin's genuinely radical intent" (446). Second, and perhaps more thoughtfully, Gould rejected the claim that "memes," or professed cultural units consisting of thoughts or behaviors, could evolve at all in Darwinian terms. Biological forms, after all, are drastically more confined than cultures. A platypus, for example, cannot incorporate rat genes to generate a "ratty-pus" lineage, because evolution can operate only on preexisting raw materials. Ideas and behaviors, however, can diverge in an essentially Lamarckian mode, borrowing from or incorporating potentially infinite others at any time. Religions, for instance, can and frequently do interconnect with, hijack, or simply sponge from independent creeds to form mythological hybrids (though perhaps, as with Christian churches, only to deny it later). As such, Gould chided, "cultural change will receive only limited (and metaphorical) illumination from Darwinism" (464).

Gould's criticisms of Dennett stemmed, for the most part, from the latter's 1995 attacks against Gould's pluralist ideas. Dennett, apparently, had denied the dominance of punctuated equilibrium (a theory introduced by Gould and Niles Eldredge in 1972 proposing that evolution proceeds in extended periods of relative stasis punctuated by brief intervals of rapid change) over gradualism (the traditional Darwinian expectation that significant and directional modification occurs very slowly through geological time) in the creation of new species. But only the theory of punctuated equilibrium, Gould argued, could predict exactly what we have found (and not found) in the fossil record--evidence of overwhelming changelessness and sudden morphological macroevolution among small and geographically peripheral populations. Gradualism, by contrast, simply cannot account for the archeological facts. So, too, had Dennett maligned the importance of "spandrels," structural yet nonadaptive by-products of evolutionary change, as fodder for later adaptive reuse or exaptation. Because organisms are profusely complex and integrated creatures, Gould explained, adaptive change always casts off material side consequences akin to architectural spandrels, or the triangular spaces left over between a rounded arch and its surrounding rectangular flame and ceiling. Consider reading and writing, for example. Each must have originated as a nonadaptive spandrel, since the human brain achieved its present size and structure tens of thousands of years prior to literacy. "Taken together," Gould concludes, "punctuated equilibrium and spandrels invoke the operation of several important principles in addition (and sometimes opposed) to conventional natural selection" (456).