Teaching a Stone to Talk (11 page)

Charles Darwin came to the Galápagos in 1835, on the
Beagle
; he was twenty-six. He threw the marine iguanas as far as he could into the water; he rode the tortoises and sampled their meat. He noticed that the tortoises' carapaces varied wildly from island to island; so also did the forms of various mockingbirds. He made collections. Nine years later he wrote in a letter, “I am almost convinced (quite contrary to the opinion I started with) that species are not (it is like confessing a murder) immutable.” In 1859 he published
On the Origin of Species
, and in 1871
The Descent of Man
. It is fashionable now to disparage Darwin's originality; not even the surliest of his detractors, however, faults his painstaking methods or denies his impact.

Darwinism today is more properly called neo-Darwinism. It is organic evolutionary theory informed by the spate of new data from modern genetics, molecular biology, paleobiology—from the new wave of the biologic revolution which spread after Darwin's announcement
like a tsunami. The data are not all in. Crucial first appearances of major invertebrate groups are missing from the fossil record—but these early forms, sometimes modified larvae, tended to be fragile either by virtue of their actual malleability or by virtue of their scarcity and rapid variation into “hardened,” successful forms. Lack of proof in this direction doesn't worry scientists. What neo-Darwinism seriously lacks, however, is a description of the actual mechanism of mutation in the chromosomal nucleotides.

In the larger sense, neo-Darwinism also lacks, for many, sheer plausibility. The triplet splendors of random mutation, natural selection, and Mendelian inheritance are neither energies nor gods; the words merely describe a gibbering tumult of materials. Many things are unexplained, many discrepancies unaccounted for. Appending a very modified neo-Lamarckism to Darwinism would solve many problems—and create new ones. Neo-Lamarckism holds, without any proof, that certain useful acquired characteristics may be inherited. Read C. H. Waddington,
The Strategy of the Genes
, and Arthur Koestler,
The Ghost in the Machine
. The Lamarckism/Darwinism issue is not only complex, hinging perhaps on whether DNA can be copied from RNA, but also politically hot. The upshot of it all is that while a form of Lamarckism holds sway in Russia, neo-Darwinism is supreme in the West, and its basic assumptions, though variously modified, are not overthrown.

So much for scientists. The rest of us didn't hear Darwin as a signal to dive down into the wet nucleus of a cell and surface with handfuls of strange new objects. We were still worried about the book with the unfortu
nate word in the title:
The Descent of Man
. It was dismaying to imagine great-grandma and great-grandpa effecting a literal, nimble descent from some liana-covered tree to terra firma, scratching themselves, and demanding bananas.

 

Fundamentalist Christians, of course, still reject Darwinism because it conflicts with the creation account in Genesis. Fundamentalist Christians have a very bad press. Ill feeling surfaces when, from time to time in small towns, they object again to the public schools' teaching evolutionary theory. Tragically, these people feel they have to make a choice between the Bible and modern science. They live and work in the same world as we, and know the derision they face from people whose areas of ignorance are perhaps different, who dismantled their mangers when they moved to town and threw out the baby with the straw.

 

Even less appealing in their response to the new evolutionary picture were, and are, the social Darwinists. Social Darwinists seized Herbert Spencer's phrase, “the survival of the fittest,” applied it to capitalism, and used it to sanction ruthless and corrupt business practices. A social Darwinist is unlikely to identify himself with the term; social Darwinism is, as the saying goes, not a religion but a way of life. A modern social Darwinist wrote the slogan “If you're so smart, why ain't you rich?” The notion still obtains, I believe, wherever people seek power: that the race is to the swift, that everybody is
in
the race, with varying and merited degrees of success or failure, and that reward is its own virtue.

Philosophy reacted to Darwin with unaccustomed good cheer. William Paley's fixed and harmonious universe was gone, and with it its meticulous watchmaker god. Nobody mourned. Instead philosophy shrugged and turned its attention from first and final causes to analysis of certain values here in time. “Faith in progress,” the man-in-the-street philosophy, collapsed in two world wars. Philosophers were more guarded; pragmatically, they held a very refined “faith in process”—which, it would seem, could hardly lose. Christian thinkers, too, outside of Fundamentalism, examined with fresh eyes the world's burgeoning change. Some Protestants, taking their cue from Whitehead, posited a dynamic god who lives alongside the universe, himself charged and changed by the process of becoming. Catholic Pierre Teilhard de Chardin, a paleontologist, examined the evolution of species itself, and discovered in that flow a surge toward complexity and consciousness, a free ascent capped with man and propelled from within and attracted from without by god, the holy freedom and awareness that is creation's beginning and end. And so forth. Like flatworms, like languages, ideas evolve. And they evolve, as Arthur Koestler suggests, not from hardened final forms, but from the softest plasmic germs in a cell's heart, in the nub of a word's root, in the supple flux of an open mind.

 

Darwin gave us time. Before Darwin (and Huxley, Wallace, et al) there was in the nineteenth century what must have been a fairly nauseating period: people knew about fossils of extinct species, but did not yet know
about organic evolution. They thought the fossils were litter from a series of past creations. At any rate, for many, this creation, the world as we know it, had begun in 4004
B.C.
, a date set by Irish Archbishop James Ussher in the seventeenth century. We were all crouched in a small room against the comforting back wall, awaiting the millennium which had been gathering impetus since Adam and Eve. Up there was a universe, and down here would be a small strip of man come and gone, created, taught, redeemed, and gathered up in a bright twinkling, like a sprinkling of confetti torn from colored papers, tossed from windows, and swept from the streets by morning.

The Darwinian revolution knocked out the back wall, revealing eerie lighted landscapes as far back as we can see. Almost at once, Albert Einstein and astronomers with reflector telescopes and radio telescopes knocked out the other walls and the ceiling, leaving us sunlit, exposed, and drifting—leaving us puckers, albeit evolving puckers, on the inbound curve of space-time.

III

It all began in the Galápagos, with these finches. The finches in the Galápagos are called Darwin's finches; they are everywhere in the islands, sparrowlike, and almost identical but for their differing beaks. At first Darwin scarcely noticed their importance. But by 1839, when he revised his
Journal
of the
Beagle
voyage, he added a key sentence about the finches' beaks: “Seeing this gradation and diversity of structure in one small, intimately related group of birds, one might really fancy that from
an original paucity of birds in this archipelago, one species had been taken and modified for different ends.” And so it was.

The finches come when called. I don't know why it works, but it does. Scientists in the Galápagos have passed down the call: you say psssssh psssssh psssssh psssssh psssssh until you run out of breath; then you say it again until the island runs out of birds. You stand on a flat of sand by a shallow lagoon rimmed in mangrove thickets and call the birds right out of the sky. It works anywhere, from island to island.

Once, on the island of James, I was standing propped against a leafless
palo santo
tree on a semiarid inland slope, when the naturalist called the birds.

From other leafless
palo santo
trees flew the yellow warblers, speckling the air with bright bounced sun. Gray mockingbirds came running. And from the green prickly pear cactus, from the thorny acacias, sere grasses, bracken and manzanilla, from the loose black lava, the bare dust, the fern-hung mouths of caverns or the tops of sunlit logs—came the finches. They fell in from every direction like colored bits in a turning kaleidoscope. They circled and homed to a vortex, like a whirlwind of chips, like draining water. The tree on which I leaned was the vortex. A dry series of puffs hit my cheeks. Then a rough pulse from the tree's thin trunk met my palm and rang up my arm—and another, and another. The tree trunk agitated against my hand like a captured cricket: I looked up. The lighting birds were rocking the tree. It was an appearing act: before there were barren branches; now there were birds like leaves.

Darwin's finches are not brightly colored; they are black, gray, brown, or faintly olive. Their names are even duller: the large ground finch, the medium ground finch, the small ground finch; the large insectivorous tree finch; the vegetarian tree finch; the cactus ground finch, and so forth. But the beaks are interesting, and the beaks' origins even more so.

Some finches wield chunky parrot beaks modified for cracking seeds. Some have slender warbler beaks, short for nabbing insects, long for probing plants. One sports the long chisel beak of a woodpecker; it bores wood for insect grubs and often uses a twig or cactus spine as a pickle fork when the grub won't dislodge. They have all evolved, fanwise, from one bird.

The finches evolved in isolation. So did everything else on earth. With the finches, you can see how it happened. The Galápagos islands are near enough to the mainland that some strays could hazard there; they are far enough away that those strays could evolve in isolation from parent species. And the separate islands are near enough to each other for further dispersal, further isolation, and the eventual reassembling of distinct species. (In other words, finches blew to the Galápagos, blew to various islands, evolved into differing species, and blew back together again.) The tree finches and the ground finches, the woodpecker finch and the warbler finch, veered into being on isolated rocks. The witless green sea shaped those beaks as surely as it shaped the beaches. Now on the finches in the
palo santo
tree you see adaptive radiation's results, a fluorescent splay of horn. It is as though an archipelago were an arpeggio, a rapid series of distinct
but related notes. If the Galápagos had been one unified island, there would be one dull note, one super-dull finch.

IV

Now let me carry matters to an imaginary, and impossible, extreme. If the earth were one unified island, a smooth ball, we would all be one species, a tremulous muck. The fact is that when you get down to this business of species formation, you eventually hit some form of reproductive isolation. Cells tend to fuse. Cells tend to engulf each other; primitive creatures tend to move in on each other and on us, to colonize, aggregate, blur. (Within species, individuals have evolved immune reactions, which help preserve individual integrity; you might reject my liver—or someday my brain.) As much of the world's energy seems to be devoted to keeping us apart as was directed to bringing us here in the first place. All sorts of different creatures can mate and produce fertile offspring: two species of snapdragon, for instance, or mallard and pintail ducks. But they don't. They live apart, so they don't mate. When you scratch the varying behaviors and conditions behind reproductive isolation, you find, ultimately, geographical isolation. Once the isolation has occurred, of course, forms harden out, enforcing reproductive isolation, so that snapdragons will never mate with pintail ducks.

Geography is the key, the crucial accident of birth. A piece of protein could be a snail, a sea lion, or a systems analyst, but it had to start somewhere. This is not science;
it is merely metaphor. And the landscape in which the protein “starts” shapes its end as surely as bowls shape water.

We have all, as it were, blown back together like the finches, and it's hard to imagine the isolation from parent species in which we evolved. The frail beginnings of great phyla are lost in the crushed histories of cells. Now we see the embellishments of random chromosomal mutations selected by natural selection and preserved in geographically isolate gene pools as
faits accomplis
, as the differentiated fringe of brittle knobs that is life as we know it. The process is still going on, but there is no turning back; it happened, in the cells. Geographical determination is not the cow-caught-in-a-crevice business I make it seem. I'm dealing in imagery, working toward a picture.

Geography is life's limiting factor. Speciation—life itself—is ultimately a matter of warm and cool currents, rich and bare soils, deserts and forests, fresh and salt waters, deltas and jungles and plains. Species arise in isolation. A plaster cast is as intricate as its mold; life is a gloss on geography. And if you dig your fists into the earth and crumble geography, you strike geology. Climate is the wind of the mineral earth's rondure, tilt, and orbit modified by local geological conditions. The Pacific Ocean, the Negev Desert, and the rain forest in Brazil are local geological conditions. So are the slow carp pools and splashing trout riffles of any backyard creek. It is all, God help us, a matter of rocks.

The rocks shape life like hands around swelling dough. In Virginia, the salamanders vary from mountain ridge
to mountain ridge; so do the fiddle tunes the old men play. All this is because it is hard to move from mountain to mountain. These are not merely anomalous details. This is what life is all about: salamanders, fiddle tunes, you and me and things, the split and burr of it all, the fizz into particulars. No mountains and one salamander, one fiddle tune, would be a lesser world. No continents, no fiddlers. No possum, no sop, no taters. The earth, without form, is void.