LIFE SCIENCE

Detailed explanation-1: -The fossil record is considered to be incomplete because fossilization is a very rare phenomenon. Most organisms decompose quickly after their death, and their remains dispersed. In order for fossilization to occur, the remains have to be covered by sediments and stay undisturbed for thousands of years.

Detailed explanation-2: -To learn more about the nature of scientific theories, visit the Understanding Science website. MISCONCEPTION: Gaps in the fossil record disprove evolution. CORRECTION: While it’s true that there are gaps in the fossil record, this does not constitute evidence against evolutionary theory.

Detailed explanation-3: -The fossil record is often incomplete, in part because scientists will never be able to discover some of the fossils that are buried deep in the earth. When ocean levels dropped about 70 million years ago, marsupial mammals moved into North America and displaced many of the placental mammal species.

Detailed explanation-4: -For example, the fossil record shows us that there has been an overall increase in the complexity of organisms over time. It also shows us that there has been an increase in organism diversity. The fossil record shows us when specific types of organisms appeared, went extinct, or changed.