How have fossils provided evidence for the change in life forms on Earth?

• A. By showing a chronological sequence of organisms with transitional forms in different geological layers.
• B. By proving that only modern species have ever existed on Earth.
• C. By indicating that life forms appeared simultaneously in all rock layers.
• D. By demonstrating that all species have remained unchanged over time.

Answer: (A)

Verified step by step guidance

1. Understand the role of fossils in studying evolutionary biology. Fossils are preserved remains or traces of organisms from the past, found in geological layers. They provide direct evidence of the types of organisms that existed at different times in Earth's history.
2. Recognize the concept of transitional forms. Transitional fossils show intermediate characteristics between ancestral species and their descendants, demonstrating gradual changes over time.
3. Examine the chronological sequence of fossils in geological layers. Fossils are found in sedimentary rock layers, with older layers typically containing simpler organisms and newer layers showing more complex and diverse life forms.
4. Eliminate incorrect options. For example, fossils do not prove that only modern species have existed, nor do they indicate that life forms appeared simultaneously in all rock layers. Additionally, fossils show that species have changed over time, contradicting the idea that all species have remained unchanged.
5. Conclude that fossils provide evidence for the change in life forms on Earth by showing a chronological sequence of organisms with transitional forms in different geological layers, supporting the theory of evolution.