In central Asia, the tarpan, ancestor of the domestic horse, became extinct in the mid-1800's. Extinctions continue today, and obscure species like the noonday snail as well as spectacular ones like the whooping crane are endangered. Wild species are necessary to ensure the continued productivity of our cultivated foods. Of an estimated 80,000 types of plants known to be edible, only about 150 are extensively cultivated. The potato blight in Ireland during the 1840s led to the starvation of two million people and prompted mass emigration to the United States.
Biological diversity is thus a form of insurance.
If cultivated varieties of food fail due to disease or global changes, we can look for genetic infusions from the natural world. National parks and other preserves help ensure that vital wild resources and their genetic information will continue to exist.