Why do you suppose Darwin did not include his ideas about the evolution of man in his book The Origin of the Species?

Darwin chose not to include his ideas about the evolution of man in "The Origin of Species" primarily to avoid controversy and to focus on the broader principles of natural selection and species diversification. He understood that discussing human evolution would provoke strong reactions, given the societal and religious norms of his time. Additionally, he felt that more evidence was needed to support his ideas about human evolution, which he later addressed in "The Descent of Man." By focusing on other species, Darwin could present a more scientifically rigorous argument without the emotional and ideological distractions that human evolution would invite.