Wednesday, May 6, 2009

Plane and complicated

The other day I noticed this big London plane in the Concert Grove. The bole, or trunk, branches into two big limbs. At this crotch, there’s space for things to be collected, as in a nest, or just to gather, with time. A slender branch arches out. Look closer, because the branch’s leaves were not planetree leaves. Another plant had seeded in there, finding enough material to root. Surely you’ve noticed those ailanthus growing out of the tops of abandoned roofs. Or those trees that seem to sprout from the sides of mountains? In the Gunks, the pitch pines cling to the hard rock of ridges. The tenacity of life continues to surprise me.

I have been reading Jonathan Weiner’s The Beak of the Finch. It is about Peter and Rosemary Grant’s more than three decades of research in the Galapagos, where they and generations of assistants have watched evolution take place in real time among, so appropriately, the archipelago’s finches. Rosemary Grant recently gave an excellent talk at the Linnaean Society (which has its meetings in the Museum of Natural History, after hours), summarizing the work and inspiring me to track down the book as well as the Grant’s own book, How and Why Species Multiply.

There are thirteen species of finches on the Galapagos, but Darwin famously didn’t pay all that much attention to them originally. He was more interested in the islands’ mockingbirds. Indeed, he didn’t differentiate among the island sources of his finch specimens. It was only later, after his ornithological expert had classified the finches, that they came to influence his thinking. For Darwin, like all young men trained for the ministry, knew that species were created by God and fixed for all time. It was just that damned sticky wicket of puzzling evidence that he began to see all around him on the ground and in the fossils, plus the notions he’d inherited from his eccentric uncle Erasmus, and others, not to mention Lyell on geology, who suggested that the earth was rather older than the “begat” counters believed – it all picked at him like a finch with a twig working away for grubs in a tree, or in the lean times (the Galapagos are subject to the whims of El Nino, with multi-year droughts followed by torrential rainfall and tropical orgies of plant-growth) actually pecking away at the backs of boobies for blood.

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