The Song of the Cell: An Exploration of Medicine and the New Human

by Siddhartha Mukherjee

And now the third branch: archaea. It may be the singularly most startling fact in the history of taxonomy that this full branch of living beings remained undiscovered until about fifty years ago. In the mid-1970s, Carl Woese, a professor of biology at the University of Illinois at Urbana-Champaign, used comparative genetics—the comparison of genes across various organisms—to deduce that we had misclassified not just some arcane microbe but rather an entire domain of life. For decades, Woese fought a spirited but lonely, bitter war that left him ragged at the edges. Taxonomy wasn’t just missing the point, he insisted, it was missing a whole living domain. Archaea, Woese argued, were not “almost like” bacteria or “almost like” eukaryotes. (“Almost like” is the taxonomist’s version of a parent saying to a child, “Go away, you’re bothering me.”)