Which is more efficient, a 747 or a bird in flight? Which is stronger, a vine or a rope? Which is better designed, a lobster claw or a pair of pliers? Who builds better, nature or us? Human technology has taken a mere 10,000 years or so to develop; nature's selected designs--the look and function of animals and plants--are billions of years old. Although the two technologies share the same physical environment--the same building materials, gases, and minerals; the same temperature range; and the same force of gravity--they produce vastly different results. Human designers love right angles, but nature chooses to be round, curved, and without right angles. Humans find metals the most marvelous of materials, but no structure in nature is metallic. We use rotating wheels in diverse ways, but nature's only true wheels come in bacteria. We prefer to make surface ships, while nature swims. Our hinges turn because their parts slide, while natural hinges turn because their structure bends, like a rabbit's ears. Man-made machines have hot combustion engines; nature does its work at local temperatures. Questions arise from these differences. Does nature have some essential superiority? Why have the two technologies taken such separate courses? Cats' Paws and Catapults is about the way living things work--how they walk, run, jump, fly, and grow. In short, this book introduces the reader to the field of biomechanics and explains how physical law and historical accident became our world's supreme architects.