Move in/Through Gases
Living systems must move through gases (which are less dense than liquids and solids) such as those in the earth’s atmosphere. The greatest challenge of moving in gases is that because the living system is heavier than the gas, it must overcome the force of gravity. Moving efficiently in this light medium presents unique challenges and opportunities for living systems. As a result, they have evolved countless solutions to optimize drag and increase lift so that they can stay aloft and take advantage of variable currents. Additionally, they must overcome gravity when moving from a liquid or solid into the air. The fairyfly, the smallest known insect, is a tiny wasp that must move through the air. To the wasp, air feels like a heavy liquid and to move through it, it uses special feathery oars rather than wings.
Transform Mechanical Energy
Mechanical energy is made up of kinetic energy (the energy of an object in motion) and potential energy (stored energy). Organisms use mechanical energy in a variety of ways, including capturing prey, transporting seeds, and moving around.
Modify Position
Many resources that living systems require for survival and reproduction constantly change in quantity, quality, and location. The same is true of the threats that face living systems. As a result, living systems have strategies to maintain access to shifting resources and to avoid changing threats by adjusting their location or orientation. Some living systems modify their position by moving from one location to another. For those that can’t change location, such as trees, they modify position by shifting in place. An example of an organism that does both is the chameleon. This creature can move from place to place to find food or escape predators. But it also can stay in one place and rotate its eyes to provide a 360-degree view so that it can hunt without frightening its prey.