AP BIOLOGY

Detailed explanation-1: -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. Long, pointed beaks made some of them more fit for picking seeds out of cactus fruits.

Detailed explanation-2: -1: Darwin’s Finches: Darwin observed that beak shape varies among finch species. He postulated that the beak of an ancestral species had adapted over time to equip the finches to acquire different food sources.

Detailed explanation-3: -Birds’ beaks are the tools they have to use to gather food. The best adapted (fittest) to the available food have the best chance of surviving (not starving to death) and of having descendants. The different variations in these beak forms are each an experiment in natural selection.

Detailed explanation-4: -Changes in the size and form of the beak have enabled different species to utilize different food resources such as insects, seeds, nectar from cactus flowers as well as blood from iguanas, all driven by Darwinian selection.