In the Galapagos Islands, there were many species of tortoises, woodpeckers and other animals. Why were the animals like the tortoises so different in appearances, when they lived on neighbor islands?

The animals were different because there were things the animals need to adapt to in the Galapagos that may have changed their appearance. for example a bird may have a different shaped beak because they started to evolve so they could eat foods that were available to them on the island