The answer is muscle or the muscular system. Muscular system is made up of muscle tissue that helps move the body and move materials through the body. In simpler explanation, muscle moves you. Muscles are bundles of cells and fibers that work in a simple way. They tighten up and relax. It consists of skeletal, smooth and cardiac muscles. <span />
A theory of evolution that states that a species evolves in spurts of rapid change and then goes through periods of no change is known as <span>punctuated equilibrium.</span>
