NEET BIOLOGY

Detailed explanation-1: -What most likely caused the finches on the Galapagos Islands to have beaks that were differnt from the finches living on the South American mainland? They were different types of food available on the island.

Detailed explanation-2: -On the Galapagos Islands, Darwin also saw several different types of finch, a different species on each island. He noticed that each finch species had a different type of beak, depending on the food available on its island. The finches that ate large nuts had strong beaks for breaking the nuts open.

Detailed explanation-3: -With them being isolated from the main population, they developed variations in the size of their beak due to their different feeding behaviors and their interaction with the environment and other organisms. Since they rarely flew over open water, they no longer share traits with the common gene pool anymore.

Detailed explanation-4: -Figure 18.1C. 1: Finches of Daphne Major: A drought on the Galápagos island of Daphne Major in 1977 reduced the number of small seeds available to finches, causing many of the small-beaked finches to die. This caused an increase in the finches’ average beak size between 1976 and 1978.

Detailed explanation-5: -Then, natural selection would probably favor different varieties in the different islands.” In other words, beaks changed as the birds developed different tastes for fruits, seeds, or insects picked from the ground or cacti.