Dunn, Rob. "The Trouble with Biodiversity." SEED MAGAZINE October 7, 2008.

Alexander von Humboldt's 200-year-old work came close to explaining the distribution of life on Earth. A bit more work and Darwin's theory of natural selection should have been enough to complete Humboldt's picture. But it wasn't. Yes, exploring biodiversity has gotten much easier. With vast computer databases on the distributions of species, we can recreate the list of species that Humboldt might have seen as he traveled. Using evolutionary trees built from fossils, genes, and the structures of living creatures, we can trace the diversification of entire groups of organisms. With satellites we can even model patterns of diversity from space. Nevertheless, instead of an explanation for the patterns Humboldt first saw, we have explanations, plural. Lots of them. . . . The trouble is that revealing the story of biological diversity is akin to reconstructing a lost novel on the basis of chapter headings and fragments of text. From those pieces, we know that the story is grand. But many narratives can be constructed from the same fragments, many stories made to fill out the bits and pieces of the drama we have observed. It remains tempting to believe that with enough time, a single, powerful narrative might come. But it might not. There may be questions in biology for which a consensus will never be reached, but instead for which there are multiple serviceable explanations, none of them quite right, but none of them terribly easy to prove wrong either. . . . Read the rest here: http://www.seedmagazine.com/news/2008/10/the_trouble_with_biodiversity.php.