Which evolutionary process best explains the presence of 14 different species of finches on the Galápagos Islands?

• A. Artificial selection
• B. Genetic drift
• C. Adaptive radiation
• D. Convergent evolution

Answer: (C)

Verified step by step guidance

1. Understand the concept of adaptive radiation: Adaptive radiation is an evolutionary process where organisms diversify rapidly into a variety of forms to exploit different ecological niches. This often occurs when a single ancestral species colonizes a new environment with diverse resources and limited competition.
2. Recognize the context of the Galápagos Islands: The Galápagos Islands are isolated and have unique ecological niches, which provide an ideal setting for adaptive radiation to occur. The finches on these islands evolved to adapt to different food sources and habitats.
3. Examine the traits of the finches: The 14 species of finches on the Galápagos Islands exhibit variations in beak size and shape, which are adaptations to specific diets such as seeds, insects, or nectar. These differences are evidence of evolutionary divergence driven by ecological pressures.
4. Compare adaptive radiation to other evolutionary processes: Artificial selection involves human intervention, which is not applicable here. Genetic drift refers to random changes in allele frequencies, which does not explain the systematic adaptation to niches. Convergent evolution involves unrelated species developing similar traits due to similar environments, which is not the case for the finches as they share a common ancestor.
5. Conclude that adaptive radiation is the best explanation: The presence of 14 different species of finches, each adapted to a specific ecological niche, is a classic example of adaptive radiation resulting from the colonization of the Galápagos Islands by a common ancestral species.