Darwin’s finches are not an example of

Darwin’s finches exemplify divergent evolution, adaptive radiation and natural selection. They are not an example of convergent evolution. 

• Divergent evolution occurs when a common ancestor gives rise to multiple descendant species, and these species evolve different traits or adaptations in response to different environmental conditions or niches. In the case of Darwin's finches, they all share a common ancestor (the seed-eating finch), but they have diversified into distinct species with different beak shapes and feeding strategies based on the specific food resources available on their respective islands.
• Adaptive Radiation: Adaptive radiation is a type of divergent evolution where a single ancestral species diversifies into a variety of species, each adapted to exploit different ecological niches. The finches in the Galápagos Islands are an excellent example of adaptive radiation because they have evolved into numerous species with specialised beaks for various types of food, including seed-eating, insect-eating, cactus flower-feeding, and more.
• Natural Selection: Darwin noted that the variations in beak shape and size among the finches were adaptive traits that allowed them to survive and reproduce in their specific habitats. Those finches with beaks suited to the available food sources had a higher chance of survival and passing on their traits to the next generation, leading to the gradual evolution of these traits over time.