Which of the following statements about extinction is true? Choose one: A. Recent species are disappearing so slowly that resear
chers suggest our present time is another mass extinction. B. Some species may become extinct because they evolve into a new species. C. At least five mass-extinction events have occurred during the last 500 million years. D. The movement of tectonic plates does not often cause mass extinctions, because all species move along with the plate.
C. At least five mass-extinction events have occurred during the last 500 million years.
Explanation:
The history of mass extinct is related to the five mass extinctions that are caused over by the 350 million years n which many species have disappeared in there short geologic time.
A massive extinction is caused in the Permian Triassic extinction event i.e about 250 mn years ago which on an estimate has killed 90% of the species.
The Cretaceous–Paleogene extinction event that occurred over 66 million years ago is known to have wiped out the dinosaurs and many other species.
A Bottleneck effect is the sharp reduction of numbers of a population through environmental effects or human activity. It causes a loss of the genetic pool and its variety; genetic variation lowers and increases with time as random mutations occur.
