Question

test corrections change over time csa
explain why the fossil record is so incomplete. choose all that apply.
fossils can only form in sedimentary rock, so they are rare to find.
there are too many fossils to discover so humans have not had enough time to complete the fossil record.
most of the fossils are found in the ocean and are unreachable for humans to study.
not all species have hard structures that can fossilize.

Explanation:

1. "Fossils can only form in sedimentary rock, so they are rare to find." - Fossilization requires specific conditions (sedimentary rock formation), limiting where fossils form, making them rare.
2. "Not all species have hard structures that can fossilize." - Organisms without hard parts (like soft-bodied organisms) rarely fossilize, so their record is missing.

The other options are incorrect: The idea that "too many fossils" or most fossils being "unreachable in the ocean" are not primary reasons for the fossil record's incompleteness. The main reasons relate to fossilization requirements (sedimentary rock, hard structures) and geological/biological factors.

Answer:

• Fossils can only form in sedimentary rock, so they are rare to find.
• Not all species have hard structures that can fossilize.