The word genetic was coined in the early 1800's (circa 1830) by Scottish philosopher and historian Thomas Carlyle and head that meaning of "pertaining to origins". Darwin used it similarly to refer to biological origins. Although the exact mechanisms and details were not discovered until later, the idea that plants and animals pass on traits has long been known, its what farming and animal husbandry have been based on for millennia. Darwin was simply expanding on that idea to apply to more substantial change over a greater time period. The invention of the word gene and its connection to genetics came later, by almost a century (circa 1910), with the word genetic already having been in use.