Living things cannot live without eachother due to the food chain, if an animal loses it's food so will his predator and so on. Soon they will end up extinct, this is why it's important to take care of animals.
if ur asking why here it is Scientists use observation to collect and record data, which enables them to construct and then test hypotheses and theories
There are two types of body waves: P-waves travel fastest and through solids, liquids, and gases; S-waves only travel through solids. Surface waves are the slowest, but they do the most damage in an earthquake (that's a start)