Wings & Fins

Wings & Fins

Animals that move through air and water have evolved sleek, streamlined forms that harness the power of fluid dynamics to propel themselves. While they may have different evolutionary histories, their common shapes reveal the fundamental features of wing and fin biomechanics.

For fliers, long, narrow wings create more lift. They’re harder to start, but easier to maintain, allowing bigger birds to glide and soar. Short, wide wings create less lift, forcing birds to flap to stay aloft. These wings are easy to start, but take lots of energy to maintain. “Pointy” wings reduce drag and fly fast, while “round” wings are slower.

Many aquatic creatures have “wings,” too—flippers that fly through fluid. Some insects are so small that air feels as thick as syrup for them, so they boost their ability to fly by clapping their wings over their backs, creating a vacuum that helps fling them forward. And certain snakes “fly” by opening their hinged ribcage, which turns their entire body into a wing.

Some scientists have managed to mimic the mechanics of flight and build robotic replicas of a variety of creatures. These replicas are used to test out theories of flight evolution, monitor endangered species in their natural habitats, and explore areas inaccessible to humans.