Advances that have enabled us to populate the earth have also strained the planet's: *natural apex! *

Natural environment.  By increasing the population, we are using more and more resources, such as fossil fuels, and therefore hurting the environment.

it depends on which society you are referring to. many civilization performed rituals so the gods would with their growing season but the most well known is that of the aztecs. they would make sacrifices, usually animals, but sometimes humans as well.