Biodiversity may become the rallying call for the next decade, wrote David Wake in the journal Science in 1989. Indeed, biodiversity is a word you're likely to encounter in writing about ecology and the environment today. But when Wake used it, "biodiversity" was still a relatively new addition to the English language, having first appeared in writing in the mid-1980s. Of course, the roots of biodiversity are much older. It evolved from a commingling of the descendants of the Greek noun bios, which means "mode of life," and the Latin verb divertere, which means "to turn aside" or "to go different ways."