Islands, Beaks, and Adaptation

Islands are excellent places to study evolution because they are partly isolated. A mainland may have many species moving in and out, but an island often begins with a smaller set of arrivals. Over time, those arrivals face local conditions: different foods, predators, weather, and nesting places.

Darwin became famous for observations connected with the Galapagos Islands. Later scientists studied Galapagos finches in great detail. The finches have different beak shapes, and those shapes help them use different foods. Some crack hard seeds. Some pick insects. Some feed from cactus flowers.

The key lesson is not that beaks are interesting by themselves,