Why should we care? what difference does it make if some species are extinguished, if even half of all the species on earth disappear? let me count the ways. new sources of scientific information will be lost. vast potential biological wealth will be destroyed. still undeveloped medicines, crops, pharmaceuticals, timber, fibers, pulp, soil-restoring vegetation, petroleum substitutes, and other products and amenities will never come to light. it is fashionable in some quarters to wave aside the small and obscure, the bugs and weeds, forgetting that an obscure moth from latin america saved australia’s pastureland from overgrowth by cactus, that the rosy periwinkle provided the cure for hodgkin’s disease and childhood lymphocytic leukemia, that the bark of the pacific yew offers hope for victims of ovarian and breast cancer, that a chemical from the saliva of leeches dissolves blood clots during surgery, and so on down a roster already grown long and illustrious despite the limited research addressed to it. which techniques does wilson use in this excerpt to convey important information to his readers?