Finch Beak Evolution on the Galápagos Islands

The Galápagos Islands, located in the Pacific Ocean, are famous for their unique biodiversity and the studies conducted by Charles Darwin. One of the notable aspects of evolution observed on these islands is the presence of finches with varying beak shapes. Each finch species has adapted its beak shape to exploit different food sources available in their habitats. For example, some finches have long, thin beaks suited for feeding on nectar, while others have short, stout beaks that are effective for cracking seeds. This evolutionary adaptation offers a clear illustration of how environmental pressures can lead to diversification among species.

Based on the above scenario, which statement best describes the process influencing the beak shapes of the finches?