Full House: The Spread of Excellence from Plato to Darwin. - book review

Stephen Jay Gould's latest book, Full House: The Spread of Excellence from Plato to Darwin,(*) is a grab-bag of miscellany - his successful struggle with cancer, the disappearance of the .400 hitter in baseball, Plato's theory of ideas, the history of life on earth. Somehow though he manages to weave all of this together into a grand philosophical synthesis about the meaning of life and the nature of reality.

The root of much evil in the world, according to Gould, lies in the simple statistic called "the average," or at least in the confusions that it engenders in the popular mind. One average in particular bothers Gould a great deal, because it leads to an understanding of evolution that he thinks mistaken. The fact that the average complexity of organisms on earth has increased over time suggests to many people that natural selection is a mechanism for producing complexity and, therefore, ultimately, for producing us. Even many who accept what Gould regards as the atheistic implications of Darwinism "cling" to the notion that we are the goal of evolution, the highest rung of a ladder. If one looks closely at the fossil record, however, one finds, according to Gould, that evolution has no preference for complexity. A particular lineage is just as likely to evolve toward less complexity as toward more - if it can. However, since life started with one-celled organisms, it had, on average, nowhere to go but up.

Even though the average complexity of organisms has increased over time, one-celled creatures still (and always will) vastly predominate in number. We do not live in the vaunted Age of Mammals or the Age of Man, says Gould, but in the Age of Bacteria. Far from being the goal of evolution, we are, "a tiny twig on life's tree." This "twig" undergoes a kind of evolution itself in the course of Gould's book, reappearing as "a tiny twig on the floridly arborescent bush of life," "a tiny twig, born just yesterday on an enormously arborescent tree of life," and "only a recent twiglet on an ancient and enormous genealogical bush." Only our "parochialism" and "traditional human arrogance" (as opposed, one imagines, to the cosmo-politanism and traditional self-deprecation of bacteria) leads us "to continue our traditional support for our own cosmic importance," and "to continue to view ourselves as better than all others by cosmic design."

What truly matters in evolution, Gould asserts, is not complexity but "success." For him, evolutionary success is a matter of counting, though he does not make clear why this is so or whether one should count by species or by individuals. That 80 percent of multicellular species are arthropods leads Gould to conclude that arthropods are more successful than we vertebrates. And even among the mammalian minority of vertebrates, "the greatest successes" are "bats, rats, and antelopes," not primates, who can boast only 200 species. However, to evaluate the success of a single species, such as Homo sapiens, the counting must be by individuals; and, on this basis, Gould judges bacteria to be the champions and the human race a flop.

There is a problem of consistency here, which Gould does not notice. There are more species of antelopes than of primates, but more human beings than antelopes; more species of fish than of mammals, but more dogs than snail darters. In any case, it is quite doubtful that proliferation of species is a sign of success. Homo sapiens has a flexibility made possible by his complexity, and, in particular, by his intelligence, which allows him to take advantage of a thousand ecological niches without fragmenting into a thousand different species. Nor does the number of individuals seem a more sensible measure of success. Size obviously has a lot to do with bacterial "success." There are more bacteria than people for much the same reason that there are more grains of sand than boulders.

Indeed, it is difficult to understand why Gould should stop at living things. There are vastly more molecules in the atmosphere than bacteria on (or in) the earth. Why is this not the Age of Air? And why should one not count the dust under one's bed and compare it to the population of China? Does not the fact that cosmic evolution has produced more dust particles than Chinese tell us something? One could even apply the same criteria to ideas. Disraeli observed that "Mormon counts more votaries than Bentham." We are worse off now, for more people will buy books on astrology than will buy Full House. Indeed, Gould's ideas could be said to be but a twig on the arborescent bush of human opinion.

Gould is overawed by other large numbers. The vast age and size of the universe in comparison to human scales are further evidence to him of human insignificance in the cosmic scheme. But these numbers can be looked at in another way. The universe must be as old as it is for life to have had time to evolve, and as large as it is for such huge times to be possible. (General Relativity relates the size and longevity of the universe.) Size and number are matters of physical requirements not "cosmic importance." There are basic physical reasons why living things must be small compared to the universe and large compared to atoms.

The "plain meaning" of evolution for Gould is that we were not "meant to be here"; we are a cosmic accident. The emergence of complex beings may have been an inevitable consequence of evolution (even if not its "goal"), but that complexity did not have to take the form of high intelligence. Says Gould:

If we could replay the game of life again and again, the [organisms] of greatest complexity would be wildly and unpredictably different in each rendition - and the vast majority of replays would never produce ... a creature with self-consciousness. Humans are here by the luck of the draw, not the inevitability of life's direction or evolution's mechanism.

Nor, he insists, are we here by some "cosmic preference." Gould seems strangely unaware that these considerations cut rather against atheism than against belief in a Creator. Religious believers say that we are here by the preference not of the cosmos but of God. It is atheists who imagine that evolutionary mechanisms, the inevitability of life's direction, or some cosmic necessity are sufficient to explain human existence.

Gould believes that the notion of "the average" has confused our ideas not only about the meaning of life but about the very nature of reality. It has left "a legacy as old as Plato, a tendency to abstract a single ideal or average as the 'essence' of a system, and to devalue or ignore variation among the individuals that constitute the full population." This gives rise to our cultural "hangup" over what is "normal." Opposed to this Platonic error is the Darwinian truth. The world is not "objectively divided into obvious categories. Taxonomies are human decisions." To those who claim that some "fundamental categories [are] invariant across time and culture," he replies, "Not so - not for these or for any subjects. Categories are human impositions upon nature." Even the idea that there are two sexes is, he claims, a recent cultural development.

It is not clear what any of this has to do with Darwin or biological science, but it certainly has nothing to do with Plato. Averages are not "our closest operational approach to essences." An essence is the intelligible form of something and is not at all a statistical concept. If every person in the world were to be blinded, that would not make sightlessness normal for man or a part of his nature or essence. Nor is a blind eye merely an example of variation; it is defective as an eye, because it does not fulfill the biological function that is evident from its form. On these points, Plato, Darwin, and modern geneticists have no disagreement.

That categories are not "imposed upon nature" is, if possible, even clearer in the physical sciences. For instance, an electron and a photon are quite distinct kinds of things. That an electron has electric charge, and mass, and is a "fermion," while a photon is neutral, massless, and a "boson," involves very fundamental distinctions that are true across time and culture - indeed, to the limits of the known universe. The structure of the physical world turns out to be expressible in the forms of mathematics, the very realm of pure essences. It is not an accident that some of this century's greatest mathematicians and mathematical physicists have considered themselves Platonists.

The stated aim of this book is to "complete the Darwinian revolution." But there have been other revolutions since Darwin - in physics, mathematics, cosmology, and molecular biology - and they too have things to teach us about the universe and about man, things one will not learn from this book. I recommend it, however, for those who take pleasure in fossils.

* Harmony Books. 230 pp. $25.00.

STEPHEN M. BARR is an associate professor of physics at the Bartol Research Institute of the University of Delaware. He does research in the theory of elementary particles and cosmology.

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