The great Victorian biologist Thomas Huxley once wrote, "I know of no familiar substance forming part of our every-day knowledge and experience, the examination of which, with a little care, tends to open up such very considerable issues as does yeast." Huxley was right. Beneath the very foundations of human civilization lies yeast--also known as the sugar fungus. Yeast is responsible for fermenting our alcohol and providing us with bread--the very staples of life. Moreover, it has proven instrumental in helping cell biologists and geneticists understand how living things work, manufacturing...