Any movement of carbon between carbon reservoirs is called a

if the type of the food available changes, then the frequency of beak types will change, because birds with beaks more suited to the available food will be more successful over time.

when you breathe in, or inhale, your diaphragm contracts (tightens) and moves downward. this increases the space in your chest cavity, into which your lungs expand. the intercostal muscles between your ribs also enlarge the chest cavity. they contract to pull your rib cage both upward and outward when you inhale.