What is the difference between sexual and natural selection?

What is the best explanation for the popularity of sexual reproduction among species versus asexual reproduction?

Explain why humans are primarily monogamous instead of polygamous.

Explain the "Selfish gene" hypothesis.

What are the benefits of an evolutionary explanation of culture? What are the drawbacks?

Does it change your impression of attraction and beauty to learn that it is the result of sexual selection?

Does evolution have a goal?