Fertilisation. This is where the sperm meets the egg and fertilises it to allow it to become an embryo and hence a foetus.
The answer is Natural Selection
Meiosis is the mechanism used for producing gametes in multicellular organisms whereas it does not play any role in unicellular organisms.
Meiosis produces gamete, or sex, cells and occurs only in multicellular organisms.
Mitosis produces somatic, or body, cells and can occur in both multi and uni cellular organisms.
After waves break on shore, the water runs down the beach back into the ocean. Waves transport energy, not water. As a wave crest passes, the water particles move in circular paths. The movement of the floating inner tube is similar to the movement of the water particles.