Answer:
Stabilizing selection results in a decrease of a population 's genetic variance when natural selection favors an average phenotype and selects against extreme variations. In directional selection, a population's genetic variance shifts toward a new phenotype when exposed to environmental changes.
Explanation:
I don't bite, don't worry
Irrigation system gave the ancient civilizations fertile land which helped crops grow. It also allowed for ease of watering which made the process of farming faster.
The answer is most likely the last option.
Is by producing money for everyone
It is the central nervous system that takes charge of the body's involuntary functions outside conscious awareness. It is this system that is responsible for all of the body's involuntary acts, such as breathing, blinking, etc.