Yeasts are single-celled fungi. They are essential components of the modern
world, ours and theirs, and yet their stories are hidden. Their consequences
often take centre stage, but they themselves are rarely featured, whether in
history, art, or even science. This absence has taken on new importance as
it is realized that some yeast species may have begun to go extinct. These
yeasts are threatened, of all things, by the declines in insect populations and,
of course, indirectly and directly, by us. But this is the end of the story –
let us start a little earlier.