Darwin's observation that Galápagos finches have many similar physical characteristics supports which idea?

• A. They evolved from separate ancestors
• B. They are identical to each other
• C. They descended from a common ancestor
• D. They have no relationship

Answer: (C)

Shared ancestry explains why these Galápagos finches share many physical traits. All of these birds come from a single ancestral species, and as they spread to different islands, natural selection shaped their beaks to fit different food sources while preserving the overall bird body plan. That common origin naturally produces the similar skeletons and features we see, even as variations like beak size and shape arise to suit different environments. If they came from separate origins, we wouldn’t expect so many core similarities; and the observed variation among beaks shows diversification from that shared ancestor.