Richard Keynes—the British physiologist and a direct descendant of Charles Darwin—has recently noted that it was actually mockingbirds rather than the finches that led to Darwin’s earliest intuitions about the mutability of species. Darwin's ornithological notes first point out that Spanish sailors can tell you the precise island that any tortoise comes from based entirely on the shape and size of its saddle-shaped carapace ("galápago" in Spanish). Darwin then adds, of his own recently collected specimens of mockingbird, that each "kin" (species, type) is found "exclusively" on only one island. If each of these islands has a different tortoise, and each a different mockingbird, then these different species must have gotten here somehow. Since they could not have all traveled here via water, some creatures must have been "created" here. They must have taken shape here. They must have evolved. In the next sentence, Darwin drops the scientific bombshell that will send shock waves shuddering through the next two centuries. The facts that Darwin has recorded, he says, a few simple observations about tortoises and mockingbirds, might—here he almost pauses in his own syntax—"undermine the stability of Species." God did not make every type of creature in a fixed and unalterable way in seven days, or seven eons. The laws of nature have generated creatures since the beginning of life on earth, and those laws continue to make new creatures today. Creation is happening right now.
All plants and animals on the Galápagos Islands are aboriginal, native and indigenous. Even today many are still found nowhere else on earth. All of these creatures, however, "show a marked relationship" (Darwin's diction) with their distant relatives on the mainland. Darwin could not say "their genetic relatives" because genetics would have to wait half a century for Gregor Mendel to start breeding and cross-breeding his peapods in clay pots. But Charles Darwin soon understood, as his grandfather Erasmus’s poetic description of evolution had implied, that all the giant tortoises on Albemarle Island (later called Isabella) had a kinship with their much smaller relatives back in Guayaquil on the South American mainland. These might all be aboriginal creatures, but they were all also linked to similar species on each of these islands and, even more remarkably, to their mainland relatives. Darwin called the Galápagos archipelago "a little world within itself." The idea behind his metaphor suggests that our entire planet might also be small enough to be covered with creatures that are all, in complex ways, related. He was right, of course, and the truth about that set of relationships is precisely the truth that his "Origin of Species" would confirm in 1859, more than two decades after the Beagle voyage ended.
The Galápagos Islands on which Darwin landed in 1835 were not the desirable destination of today’s eco-tourists. Herman Melville, writing two decades after Darwin’s visit, called them "heaps of cinder" in an isolated expanse of ocean, more desolate than any spot on the planet. Darwin himself called them beautiful, but he was referring only to the symmetry of their volcanic craters, a geologist’s paradise. A page later he says that no landscape could be less inviting than one’s first sight of the Galápagos island then called Chatam, now called San Cristobal. We can draw directly on Darwin’s own diction to give the full effect of this first sight. The lava looks like waves, he says, broken by great cracks and fissures, the whole scene covered with sunburned and stunted scrub-wood. There are almost no signs of life. The surface is parched and dry. The atmosphere is sultry and close. You feel as though you are standing next to a burning stove. The bushes literally stink. Even this greatest of all specimen collectors found it hard to collect here. On that famous first day ashore he had collected only a few wretched little weeds that seemed as though they should have come from an arctic landscape, not from the sunny equator. The shrubs looked as leafless as in winter, but in fact their tiny leaves were fully out, and even their flowers were in bloom. He had to get magnifier-close before he could see this indistinct detail of natural history. The tiny flowerets and leaves were almost invisible, a good lesson for any nature watcher. Only after a season of heavy rain were these islands even partially green. The same is true today. Not a very likely tourist destination, perhaps, but then it is Darwin’s own writing that has changed all of that a century and a half later. Luxury ecotouristic yacht trip, anyone? (A.N.)
Sunday, September 14, 2008
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