Paleontologists have found evidence that after a major extinction occurs, there is no particular pattern of speciation many new species often appear at about the same time a new species evolves to replace each species that became extinct most species move away because they cannot adapt

The correct answer would be - new species often appear at about the same time.

Explanation:

A biotic crisis or a mass extinction crisis is a rapid and widespread decrease in biodiversity. There is a clear change after the mass extinction, in the diversity and  of multicellular organisms.

Thus, the correct answer would be - many new species often appear at about the same time.

density and pressure