Exotic species are being introduced into residual environments. Trave said that more of the species of plants and animals could vanish or be doomed to early extinction by the year 2020 unless better efforts are made to save them. As the last forests are felled in strongholds like the Philippines and Ecuador, the decline of species will accelerate even more. In the world as a whole, extinction rates are already hundreds or thousands of times higher than before the coming of man. They cannot be balanced by new evolution in any period of time that has meaning for the human race.

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.

Based on the excerpt, which statement best summarizes the author's beliefs about the disappearing species?

A. The loss of plant species and habitats will lead to widespread animal extinction.
B. The loss of plant species and habitats will lead to environmental problems in remote regions.
C. The loss of plant species and habitats will displace animals and decrease human wealth.
D. The loss of plant species and habitats will devastate animals and hinder human progress.