Are you more likely to observe evolution between the s0 and s1 or the s0 and f1 population? explain your reasoning.

not too sure but maybe in the hot springs.

not only is it colder, it also becomes darker, less salty, and more dense.

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.