Scientists hypothesize that Earth is currently in a sixth mass extinction period when compared to the natural extinction rate. Which of the following BEST explains the baseline extinction rate?
A. the rate of species extinction compared to the fossil record
B. the rate of species extinction if human activity did not exist
C. the rate of species extinction caused by coral bleaching
D. the rate of species extinction as a result of water pollution
1 answer
B. the rate of species extinction if human activity did not exist