On the Origin of Species for Existence" Darwin includes "slow-breeding man" among other examples of Malthusian population growth. In his discussions on morphology, Darwin compares and comments on bone structures that are homologous between humans and other mammals. Darwin's early notebooks discussed how non-adaptive characteristics could be selected when animals or humans chose mates, with races of humans differing over ideas of beauty. In his 1856 notes responding to Robert Knox's "The Races of Man: A Fragment", he called this effect sexual selection. He added notes on sexual selection to his "big book on species", and in mid-1857 he added a section heading; "Theory applied
Essay on the Origin of Languages Essay on the Origin of Languages Essay on the Origin of Languages () is an essay by Jean-Jacques Rousseau published posthumously in 1781. Rousseau had meant to publish the essay in a short volume which was also to include essays "On Theatrical Imitation" and "The Levite of Ephraim." In the preface to this would-be volume, Rousseau wrote that the "Essay" was originally meant to be included in the "Discourse on Inequality", but was omitted because it "was too long and out of place". The essay was mentioned in Rousseau's 1762 book, "Emile". In this text, Rousseau lays out a narrative