With evolution as the core theme of biology, we can explain traits shared by organisms as evidence of __________ and traits that differ among organisms as evidence of __________.

• A. descent from a common ancestor; chance
• B. coincidence; adaptation
• C. systems biology; reductionism
• D. descent from a common ancestor; adaptation through natural selection

Answer: (D)

Verified step by step guidance

1. Understand the concept of evolution: Evolution is the process through which species change over time through variations and natural selection.
2. Recognize that traits shared by organisms often indicate a common ancestry. This is because organisms that share a common ancestor tend to inherit similar traits.
3. Identify that traits differing among organisms can be evidence of adaptation. Adaptation occurs when organisms evolve different traits to better survive and reproduce in their specific environments.
4. Consider the role of natural selection in adaptation: Natural selection is the mechanism by which advantageous traits become more common in a population over generations.
5. Connect these ideas to the problem statement: Shared traits suggest descent from a common ancestor, while differing traits suggest adaptation through natural selection.