Question

Appearance of teeth in the embryo of a bird proves that

• A. Ontogeny repeats phylogeny
• B. Evolution has taken place
• C. Birds have evolved from reptiles
• D. All the above

Answer 1

Answer: (A)

Even though birds lost teeth as physical structures between 60 and 80 million years ago, several studies have shown that those tissues within birds that would normally produce teeth still retain the potential to do so. For example, in 1821, Geoffrey St. Hilaire was the first scientist to publish the observation that some bird embryos exhibited evidence of tooth formation, but his contemporaries considered his work flawed.

So, the correct answer is "Ontogeny repeats phylogeny".