Which of the following patterns do scientists commonly identify in the fossil record?

• A. A lack of any chronological order in fossil layers
• B. The absence of transitional forms between major groups
• C. The appearance and extinction of species over time
• D. The constant presence of all species throughout Earth's history

Answer: (C)

Verified step by step guidance

1. Understand the fossil record: Fossils are preserved remains or traces of organisms from the past, found in sedimentary rock layers. These layers provide chronological order, allowing scientists to study the history of life on Earth.
2. Recognize patterns in the fossil record: Scientists commonly observe patterns such as the appearance of new species, the extinction of species, and transitional forms that show evolutionary links between major groups.
3. Eliminate incorrect options: For example, 'A lack of any chronological order in fossil layers' is incorrect because fossil layers are arranged chronologically, with older layers typically found deeper. Similarly, 'The constant presence of all species throughout Earth's history' is incorrect because species appear and go extinct over time.
4. Clarify transitional forms: While transitional forms may not always be abundant, they do exist and provide evidence for evolutionary changes between major groups. The absence of transitional forms is not a common pattern in the fossil record.
5. Conclude the correct pattern: The fossil record shows the appearance and extinction of species over time, reflecting the dynamic nature of life on Earth and supporting the theory of evolution.