The Beak of the Finch: A Story of Evolution in Our Time

by Jonathan Weiner

  In this way, even now, not only in test tubes but all over the planet, matter still makes tentative steps toward life. In the shallows of Darwin Bay, and in volcanic vents at the bottom of the sea, the soup is still warm. There are more inanimate molecules in the seas of this planet than there are stars in the universe. Here and there, now and then, a few of them begin to make the kinds of connections that—again, if favored, if selected generation after generation—would bring them to life. Matter may take these first steps daily and hourly in the hot springs on the sea floor beneath the Galápagos, in the deep, drowned rifts that geologists call Darwin’s Faults.

  In the laboratories, the trial soups are kept hermetically sealed, or each experiment would be cut short before it got interesting because the new molecules in the soup would be scavenged by bacteria. The waiting Pyrex ponds are sterile as the seas and shorelines of this planet before life began. But in the ocean, of course, as fast as molecules make their first gestures toward life, they are devoured. Creation in the sea has never stopped, but the niche of life is taken.

  That is why we look around us now at other planets and other suns. Are we the first, or are we only the first on this island? Are we the only ones to have evolved the twist of replication with variation—and beyond that, the twist of heightened consciousness, the crossed beak in which we feel we can grasp whole worlds?

  This is the not-so-secret mainspring of our fascination with aliens and extraterrestrial intelligence, in the century of our first wings. What we have here is a species calculating its chances and its future quite consciously and coolly: a whole species before a big move. We are perched on one rock, gauging our chances of reaching another. Our juvenile space fantasies are a species’ dreams of invasion, expansion, and domination—and they may come to pass. Someday we may sail among new enchanted archipelagoes with Tribulus seeds clinging to our boots.

  At the same time we fantasize endlessly about first encounters here on earth. This is just what Darwin’s finches would do if finches could fantasize. We know now that at any moment we ourselves may be surprised, like the finches of Santa Cruz among their anis, goats, cats, and fire ants; or like the old Easter Islanders, who once believed their solitude was greater than it was, that they were the only human beings on this earth.

  This year in the population explosion on Daphne Major, the Grants in their camp on the east rim of Daphne Major see more and more young finches winging out to sea, sometimes one by one, sometimes in small flocks, and making for the nearest moon-colored rock on the horizon, Daphne Minor. Some head for Santa Cruz, flying out and then turning around and coming back again. A few go on and on and never come back. That is our position now on the archipelago of the continents, crowded, restless and anadromous, looking up at the stars.

  DARWIN’S FINCHES MAY have made more journeys than we ever imagined. Not long ago a team of geologists surveyed the sea floor around the Galápagos. Away to the east, in the direction of the South American continent, they report in Nature, “we dredged abundant well-rounded basalt cobbles from a small seamount with a terraced summit.” They found the summits of a few other volcanoes at the bottom of the sea and dredged cobbles from them too. Though the cobbles are stained greenish-brown from lying in the depths, they look much like the worn lava rubble that lies at the feet of all the cliffs in the Galápagos. Lava does not grow in that shape at the bottom of the sea; it is worn into cobbles by the rolling of waves, like pebbles on a beach. The cobbles suggest that these drowned islands once stood above the sea. Their ages, according to the geologists’ report, range from five million to nine million years. The oldest peak lies submerged at 85° longitude, which is halfway from the Galápagos to the continent. When it stood above the waves, it may have been about the size of the island of Pinzón. It rises steeply to a generally flat summit, the geologists say, with a small peak toward the northwest edge. They see hints of a number of wave-cut terraces at different heights, “and a residual spire.” In profile, except for the spire, it is not unlike the shape of Daphne Minor. The geologists also found a second seamount nearby, which seems to have subsided faster, and which they have named “FitzRoy.” The number of rounded pebbles and cobbles they dredged up suggest to these new surveyors of buried coasts that many other islands lie drowned between the Galápagos and the continent.

  All these volcanoes, the new ones above the sea and the old ones below, were made when lava welled up through the crust of the sea floor. They mark a hot spot in the earth, where lava is always welling up. As the crust drifts eastward across this hot spot, it carries the old islands away, and new islands form in their place. The youngest islands in the Galápagos are in the west, the oldest in the east; Daphne lies precisely in the middle.

  They rise, they are discovered by seeds and birds, they support Darwinian chains of action and reaction, and they sink again to the bottom of the sea, while new islands rise in their place. This rise and fall may have gone on here in the middle of the sea for as many as eighty or ninety million years.

  The sight of Daphne Major conveys something like this to us, even in the first glance over the water, or in the last, as it revolves like a wood chip in the wake of a boat. We know we are looking at a place that was here before we came and will remain when we are gone. The very island will sink someday, and another will rise when it is drowned. The seasons will go on changing, and the cactus will suffer them. The waves will go on beating, and the cliffs will suffer them. Darwin’s finches will keep their covenant with Darwin’s islands, witnessed by a heap of stones.

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