Accuracy
The fact that we do not currently know the total number of species, in the past nor the present, makes it very difficult to accurately calculate the non-anthropogenically influenced extinction rates. As a rate, it is essential to know not just the number of extinctions, but also the number of non-extinctions. This fact, coupled with the fact that the rates do not remain constant, significantly reduces accuracy in estimates of the normal rate of extinctions.
Read more about this topic: Background Extinction Rate
Famous quotes containing the word accuracy:
“As for farming, I am convinced that my genius dates from an older era than the agricultural. I would at least strike my spade into the earth with such careless freedom but accuracy as the woodpecker his bill into a tree.”
—Henry David Thoreau (1817–1862)
“U.S. international and security policy ... has as its primary goal the preservation of what we might call “the Fifth Freedom,” understood crudely but with a fair degree of accuracy as the freedom to rob, to exploit and to dominate, to undertake any course of action to ensure that existing privilege is protected and advanced.”
—Noam Chomsky (b. 1928)
“Such is the never-failing beauty and accuracy of language, the most perfect art in the world; the chisel of a thousand years retouches it.”
—Henry David Thoreau (1817–1862)