With Darwin's Descent of Man and Freud's The Structure of the Unconscious, how did these writers change the worldview of Europeans in the 19th century?

While Darwin's Origin of Species (1859), outlining his theory of evolution by natural selection, is his most famous work, Descent of Man (1871), a book that explores the consequences of his theory for humankind, also had a significant impact on the 19th century European's worldview.
In the text he explores the consequences of evolutionary theory for human beings. He argues that civilization has actually insulated humanity from the direct effects of natural selection. Things like altruism and medicine have allowed the weak to survive. In this respect he opens the door to ideas like eugenics and larger expressions of Social Darwinism. Social Darwinism saw various manifestations, from cowboy capitalism to socialist theories of human perfection.
Freud explored the mysteries of the dark corners of the mind, opening a new frontier of human understanding. One of his famous texts in this respect was written at the beginning of the 20th century: The Interpretation of Dreams (1899). He gave us new windows into the mind, arguing that much of how we act and behave is driven by unconscious desires and thoughts.