If estimates of an extinction rate 10,000 times greater than the background rate are correct,then what percentage of all species will be extinct by the end of this century?
A) 5 - 10%
B) 10 - 25%
C) 25 - 33%
D) 25 - 50%
E) 60 - 75%

Question

Quizplus · Accepted Answer

A 10,000 times greater extinction rate translates to a predicted rate of 1 species extinction per 100 species per year. Given that it is estimated there are currently approximately 8.7 million species on Earth, the predicted extinction rate would be around 87,000 extinctions per year. Assuming this rate continues through the end of the century (80 years remaining), approximately 6.96 million species (80 multiplied by 87,000) could become extinct. This would mean approximately 80% of all species would remain, resulting in a 20% extinction rate. Since the answer choices do not allow for such a specific range, D) 25-50% is the closest range that includes a 20% extinction rate.

If Estimates of an Extinction Rate 10,000 Times Greater Than