Explanation:
The variation in finch beaks arose due to natural selection favoring specific beak shapes for different food sources. Inherited beak size variations within the population meant some finches could access certain foods more easily. These finches thrived, reproduced, and passed on their well-suited beak traits. Over generations, this led to the remarkable diversity in beak shapes seen today, where each beak is optimized for the finch's preferred food source.