Answer:
Natural selection
Explanation:
According to Darwin's theory, natural selection is the process by which individuals better adapted to their environments have more chances to survive and reproduce, and thereby their descendants will be better represented in the next generation. This mechanism exploits the existence of natural variation among members in the population which is used to select those individuals that are better adapted (i.e., with a higher adaptive fitness) for their environments. Natural selection is a key mechanism of evolution by which species change across time.
1) Cholesterol is important for the production of hormones, for example, some hormones are synthesized (made) from cholesterol - for example stereoid hormones.
2) Vitamin D is also made from cholesterol- it's an important vitamin used to support the absorption of calcium