The evolution of evolution.

Life's Solution

Inevitable Humans in a Lonely Universe

Simon Conway Morris

Cambridge University Press, $29.95, 464 pp.

Finally, a book on evolution that gets it right. To be blunt about it, not since Charles Darwin's Origin of Species has a book on evolution managed to marshal so many facts of life--and so many discrepancies in the prior orthodox model for explaining those facts--and then gone on to create a new, more plausible account for how life originated and evolved.

These are large claims, I know. To justify them I must first rehearse the discrepancies that bedevil the Darwinian account of evolution, above all that pesky question of teleology. Prior to Darwin nearly everyone took it as perfectly obvious that the giraffe's long neck was "made for" reaching vegetation in tall trees, that the eye was "made for" seeing, and so forth. Yet since complex formations such as the eye could hardly have come about by mere chance, they must have been designed by a kind of divine foresight, just as a watch requires a clever watchmaker. When Origin was published in 1859, however, that explanation lost its hold on the scientific public, or so it is claimed. In fact the situation was far more complex. Even avid Darwinians were not so sure. For example, Thomas Huxley ("Darwin's bull-dog") saw Darwinism as the perfect opportunity to set up a secular religion to rival Christianity but still believed in "saltations," big leaps in evolution to account for the transition from, say, fox to dog, and even claimed that "there is a wider teleology, that is not touched by the doctrine of evolution." On the other side of the coin (and ocean), the Harvard botanist Asa Gray rightly recognized that saltations would mean the demise of the theory of natural selection and vigorously defended Darwin while remaining an orthodox Congregationalist, whereas his great rival at Harvard, the zoologist Louis Agassiz, attacked Origin of Species but abandoned the Calvinist religion of his Swiss homeland and became a Unitarian.

These cat fights among the Darwinians continue right down to today. Thus, in order to drive home the point that evolution has no goal and that humans are a complete fluke, the late Harvard professor Steven Jay Gould insisted that if we rewound the tape of evolution and started the whole process over again, the chances would be vanishingly small of evolution producing, yet one more time, the same roaches and sharks, tulips and mushrooms, humans and crabs, that we know today. Of course if the outcome of evolution were that much of a fluke, then, as the philosopher Daniel Dennett points out in Darwin's Dangerous Idea, the search for intelligent life on other planets would be as pointless as a search for extrater-restrial kangaroos. The whole point of such a search rests on the assumption that evolution will inevitably tease out the potential for intelligence already lurking, however embryonically, in the prebiotic chemical soup of other life-bearing planets. Still, if intelligence is well-nigh inevitable, does not such inevitability say something about the inherent nature of the universe: if humans were so inevitable from the start, why all the sneers from devout Darwinians at man as an insignificant worm in the cosmic slime?

In the midst of this at-times heated debate, one other option gets slighted. Dennett certainly scores a point when he says that if we are as much of a fluke as Gould would hold, then we have next to no hope of finding intelligent life else-where in the universe. But it can also be that intelligence is as built into the logic of evolution as Dennett says it is--and yet we can still be alone. As the subtitle to his book clearly indicates, that is Simon Conway Morris's thesis: "In other words, once you are on the path [of evolution] it is pretty straightforward, but finding a suitable planet and maybe getting the right recipe for life's origination could be exceedingly difficult: inevitable humans in a lonely universe."

No doubt both sides of his thesis--that life-friendly planets are rare, perhaps even unique, but that once life gets up and running intelligence is inevitable--are eminently debatable. Here is the point: anyone who now wants to argue against those two theses will have to take Morris's book into account, which is just why it bears such uncanny similarities to Darwin's Origin--he has moved the debate to a whole new plane. Professor of evolutionary paleobiology and earth sciences at the University of Cambridge, Morris has marshaled an enormous amount of evidence to support both prongs of his thesis (the footnotes take up about one-fifth of the book, and he seems to have read every article in every refereed journal of science).

Roughly speaking, his defense of the lonely-universe side of his argument depends on features of the solar system which, he claims, are both necessary for life yet freakishly unlikely: meaning above all the position of the sun in the Milky Way, the orbit and size of Jupiter in the solar system, and the unique way the moon was "untimely ripped" from the bowels of the earth. Without Jupiter's size and position, he argues, the earth would have been bombarded too often with asteroids; and, as with the example of the extinction of the dinosaurs from the impact of a meteor, we already know how much damage can follow in the wake of even rare impacts. Furthermore, the moon's own orbit keeps the earth rotating on a more-or-less stable axis, which would otherwise tilt wildly, like a child's spinning toy top, and cause immense climatic upheavals. Still, the moon is no ordinary satellite, says the author, like the other attendant moons in the solar system, which had been formed--as in fact were the earth and other planets as well--by the clustering effect of gravity on as teroids and cosmic dust. According to the author, our essential moon was midwifed by a most freakish collision of another forming planet, roughly the size of Mars, with earth. The impact of this collision was "just right" to allow the spalled-off material to form the moon, while the rest of the material went to make up a bigger earth, whose size was also crucial for allowing the right kind of skeletal life to evolve later.

For the life-is-inevitable side of his argument Morris plays his most significant trump card, the fact of convergence, that is, the frequency by which certain evolutionary strategies were independently chosen over and over again across a wide spectrum of phyla. Examples would be sophisticated vocalizations, vision, echolocation, viviparity, warm-bloodedness, sexual dimorphism, division of labor (even agriculture!), and of course most crucially, larger and more complex brains.

Because Darwinism gave a new explanation for how and why each organism is so well adapted to its environment, this enormous record of convergence surely must say something as well about the environment. In other words, the fact that so many biological forms developed photosensitive cells and then eyes (or their equivalents) also testifies to the ubiquity of light, just as the fact that wings developed independently on insects, birds, bats, some dinosaurs, and so forth, testifies to the density and viscosity of the atmosphere of the earth. So too with complex brains: to be adaptive, brains have to evolve in response to the environment. In other words, if wings evolve over against and in response to air and eyes over against and in response to air and eyes over against and in response to light, then brains must evolve over against and in response to something like "mental air." By that admittedly metaphorical term I mean those a priori ideal structures already part of the universe that make a mathematics-capable brain possible in the first place. In other words, Darwinism is not only compatible with Platonism, it presupposes it.

Although such a "Darwinian Platonism" is not part of the thesis of Morris's epochal book, I cannot but think that something like that metaphysic forms the conclusion of his work, for in the last two chapters he turns his guns on the Darwinian materialistic atheists ("ultra-Darwinists" in his terminology) and delivers a fierce polemic against their anti-Christian bias, a bias he rightly calls quasireligious in its fervor ("Richard Dawkins is arguably England's most pious atheist," he quips):

    Notwithstanding the quasi-religious enthusiasms of ultra-Darwinists,
    their own understanding of theology is a combination of ignorance
    and derision, philosophically limp, drawing on cliches, and happily
    fuelled by the idiocies of the so-called scientific creationists. It
    seldom seems to strike the ultra-Darwinists that theology might have
    its own richness and subtleties, and might--strange
    thought--actually tell us things about the world that are not only
    to our real advantage, but will never be revealed by science. In
    depicting the religious instinct as a mixture of irrational
    fundamentalism and wish-fulfillment they seem to be simply unaware
    that theology is not the domain of pop-eyed flat-earthers.

As I say, finally a book on evolution that gets it right!

Edward T. Oakes, SJ, is Chester & Margaret Paluch Professor of Theology at the University of St. Mary of the Lake in Mundelein, Illinois, the seminary of the Archdiocese of Chicago.