Question

When geologists refer to the " Big Five", what are they referring to?

1. The five most important organisms that have become extinct.
2. The five largest mass extinctions in earths history.
3. The five most influential events that have changed the surface of the earth.
4. The five most important inventions that have allowed scientists to study mass extinctions.

Answer 1

Number 2 is the right answer

hope it helps, murdle:)

Answer 2

2) The five largest mass extinctions in earths history.

Step-by-step explanation:

The five largest mass extinctions in earth's history were:

1. End Ordovician, 444 million years ago, 86% of the total species lost
2. Late Devonian, 375 million years ago, 75% of the total species lost
3. End Permian, 251 million years ago, 96% of the total species lost
4. End Triassic, 200 million years ago, 80% of the total species lost
5. End Cretaceous, 66 million years ago, 76% of all the total species lost