What does the fossil record show after mass extinction events?

• A. Fewer species exist and no new lineages appear.
• B. Many new species appear after each mass extinction event.
• C. Biodiversity remains unchanged.
• D. Only fossils of extinct species survive.

Answer: (B)

Mass extinction events clear the field, wiping out many species and freeing up ecological roles. In the fossil record, this often leads to a rapid rebound in diversity as surviving organisms radiate into the empty niches and evolve into many new lineages. This burst of speciation—adaptive radiation—fills ecosystems with a variety of forms that hadn’t existed before the extinction. So, after these dramatic events, you don’t just lose species; you also see many new species appear as life reorganizes and diversifies. That’s why the correct idea is that many new species appear after mass extinction events.