Which of the following is evidence of evolution?

Step 1: Analyze the question The question asks which option is evidence of evolution. Option A says "All of the above," so we need to check whether B, C, and D are each valid evidence.

Step 2: Explain the concepts Evolution is the gradual change in organisms over generations. Scientists support it with several lines of evidence:

• Fossils of extinct organisms (C): Fossils show how life forms have changed over time. They also show transitional forms, such as Archaeopteryx, which links reptiles and birds.
• Homologous structures (D): These are structures with the same basic anatomy but different functions, inherited from a common ancestor. Examples are the forelimbs of humans, bats, whales, and cats. This is evidence of divergent evolution.
• Similarities in embryonic development (B): Vertebrate embryos, including fish, birds, and humans, show gill slits and tails at early stages. This points to a common ancestry.

Step 3: Evaluate the options

• B is valid evidence (comparative embryology).
• C is valid evidence (palaeontology).
• D is valid evidence (comparative anatomy).
• Since B, C, and D are all valid, "All of the above" (A) is correct.

Step 4: Answer The correct answer is A. All of the above.

Tip: Remember the main evidence for evolution with "FEAB": Fossils, Embryology, Anatomy (homologous structures), and Biochemistry/molecular (DNA and protein similarities). When an "All of the above" option appears and each of the other options is a known piece of evidence, it is usually the answer.