The First Art Newspaper on the Net by Sabrina Imbler (NYT NEWS SERVICE) .- More than a century ago, a bluish butterfly flitted among the sand dunes of the Sunset District in San Francisco and laid its eggs on a plant known as deerweed. As the citys development overtook the dunes and deerweed, the butterflies vanished, too. The last Xerces blue butterfly was collected in 1941 from Lobos Creek by an entomologist who would later lament that he had killed what was one of the last living members of the species. But was this butterfly truly a unique species? Scientists could all agree that the...