Some believe it comes from the Greek bios, meaning life, and the Latin diversitas; others see it as a portmanteau formed by contracting the English phrase biological diversity. The term first appeared in English in 1968, but entered scientific usage in 1980 thanks to the American biologist Thomas Lovejoy (born in 1941). A quarter of a century later, the Rio Earth Summit popularized it among the general public; adapted into French, it was added to the Larousse dictionary in 1994. Its connotations vary from person to person, but everyone uses it to voice concern about the disappearance of numerous species, even microscopic ones—a loss that could jeopardize the balance of life on Earth.