L'origine dell'uomo e la selezione sessuale

Given the broad scope of the book, I'm curious about what influenced Darwin's focus on certain traits or behaviors over others. Did he prioritize certain evidence or theories?

Some sections feel quite candid and controversial even today. How did readers from Darwin's time react to these ideas, and how do modern readers interpret them?

The way he draws parallels is fascinating and seems to challenge many beliefs. Was this approach common at the time, or was Darwin breaking new ground?