what most likely caused the finches on the galapagos islands to have different beaks than living in south america?

Answer 1

It is believed that the different food sources available on the Galapagos Islands compared to South America led to natural selection, where the finches with beaks better suited for the available food were more likely to survive and reproduce. Over time, this resulted in the development of different beak shapes and sizes among the finch populations on the Galapagos Islands.