The Tangled Tree: A Radical New History of Life. David Quammen

keen to fingerprint some salt lovers. He reckoned that “if unusual cell walls meant anything, perhaps the extreme halophiles would turn out to be members of our new ‘far out’ group.” George Fox, by this time, had left for the University of Houston. With Fox gone and his other lab people already busy, Woese couldn’t wait for another student or collaborator to come along, so he started the wet work himself. Fortunately for him, growing halophiles is relatively easy. “I donned my acid-eaten lab coat (which had hung on the back of my office door for over a decade) and went back to the bench.” He grew the cultures in quantity from samples sent by a colleague, tagged them with P-32, and turned them over to Ken Luehrsen for the dicier next step: extracting and purifying radioactive RNA. Then from Luehrsen the stuff went to Linda Magrum—“our trusty Linda,” Woese called her—for separation by electrophoresis and burning the films. Within a few months, they had their first catalog from a halophile. “It didn’t disappoint,” Woese wrote. It was another strange thing: not a bacterium after all, but a member of the archaea.

      So much for the halophiles. He turned back to the thermophilic acidophiles. When his team finished fingerprinting the coal-refuse creature, Woese sent a manuscript to the journal Nature, presenting the new ribosomal RNA catalog and making a case that this creature too belonged among the archaea. Nature rejected the paper, with a return letter that essentially said: “Who cares?”

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      The three Germans cared—not just Otto Kandler, who became a great pal to Woese, but also Wolfram Zillig, an eminent biologist who directed the Max Planck Institute for Biochemistry, in Munich, and his younger associate, Karl Stetter, formerly a student of Kandler’s. After meeting Woese and hearing firsthand about his evidence and his radical idea, Kandler carried the news back to Munich, where he shared it with Stetter, then still a junior researcher. Stetter was straddling two roles—teaching in Kandler’s institute at the University of Munich, running a lab within Zillig’s operation, commuting between them daily—and he brought Kandler’s news from America across town. When he delivered his thirdhand account in a Friday seminar at the Max Planck Institute, Wolfram Zillig’s initial reaction was cold. Zillig, born in 1925, was just old enough to remember Nazism and the war from the perspective of a soldier-aged young man. As the story comes from Karl Stetter, recounted to Jan Sapp decades later, Zillig in 1977 reacted sourly to Kandler’s scuttlebutt about Woese’s third kingdom of life. “A Third Reich?” he snapped. “We had enough of the Third Reich!”

      But Zillig’s resistance fell and his interest rose when he heard, a few months later, that Woese possessed data on the uniqueness of halophiles that nicely paralleled his data on the uniqueness of the methanogens. Zillig and Stetter then reset their own research efforts, which involved something called RNA polymerase (the enzyme that helps turn DNA code into messenger RNA), to see whether anomalies in that molecule among salt-loving “bacteria,” among heat-loving and acid-loving “bacteria,” and among methane-producing “bacteria”—anomalies that might set them apart from typical bacteria—matched the drastic anomalies Woese was finding by his own method. They did match. So maybe these microbes weren’t bacteria after all.

      Derided in the United States, controversial at best, Woese was becoming a scientific lion in Germany, at least in those erudite circles where researchers studied the molecular biology of microbes. In 1978 Kandler invited him to a major congress of microbiologists in Munich. Woese declined. In a polite but cranky letter, he groused that the National Science Foundation and NASA were being stingy with him on grant funds while enjoying the considerable publicity from his work, and also that, quite apart from the costs, travel interrupted his research. Interruptions he found annoying. He was a driven man—toward results, not companionship. But the following year, Kandler tried again, and this time Woese accepted. His hosts paid the way. They treated him well. They asked only that he deliver a keynote lecture at another microbiology conference and then a seminar at Zillig’s institute. On the night of a festive dinner, in a great hall at the University of Munich, Kandler laid on a brass section from a local choir. They gave Woese a fanfare of trumpets. Not many molecular phylogeneticists ever get that level of jazzy appreciation. It melted his frosty rime.

      Two years later, his German friends organized another meeting in Munich, this time an international conference—though they called it a workshop, suggesting informality and collaboration—devoted entirely to the archaea. It was the first such conference ever, giving the third kingdom a new measure of recognition. The attendance was relatively small, about sixty people, but included researchers from Japan, the United States, Canada, Great Britain, the Netherlands, and Switzerland, as well as the Federal Republic of Germany (West Germany), where the archaea were now big; and its program encompassed a wide range of topics and approaches. Ralph Wolfe came. So did Ford Doolittle, George Fox, and Bill Balch. Woese not only traveled to Munich again but also delivered the welcoming address—and he made that a substantive lecture, rich with ideas and provocations, not just a ceremonial greeting.

      “We are about to embark on a scientific meeting of historic significance,” he told the group (as reported later in the proceedings, edited by Otto Kandler). What they shared, this assemblage of scientists, was their concept of the archaea, which “did not exist four years ago.” They had been working, in their respective labs, with “organisms that intuitively felt peculiar”: methanogens, halophiles, thermoacidophiles. These things had seemed idiosyncratic and unrelated. We had been slow to recognize their connectedness, their unity, Woese said, because the existing framework of bacterial taxonomy was so misleading in its overview and so wrong in its details.

      “Generations of failure had discouraged the microbiologist about ever uncovering the natural relationships among the bacteria.” Here he was talking about the generations that had included Ferdinand Cohn, C. B. van Niel, and Roger Stanier. “With a few important exceptions, microbiologists were content to classify bacteria determinatively,” he added, alluding pointedly to Bergey’s Manual of Determinative Bacteriology, the authoritative handbook, and the cautious experts who had produced it for sixty years. The problem with that approach, Woese complained, was that it tried to understand bacteria only as static entities—items to be placed into categories of convenience. “Matters of their evolution became reserved for enjoyable but idle after-dinner speculation.” That’s what was missing from both microbiology and now molecular biology, he said: evolution.

      Woese was casting down a gauntlet: telling some of the most brilliant and influential figures of late-twentieth-century biology—his friend Francis Crick, Crick’s colleague James Watson, the Nobel winners François Jacob and Jacques Monod and Max Delbrück and Salvador Luria, who had counseled Ralph Wolfe to stay away from Woese for the sake of his good reputation—that they were shallow, mechanistic thinkers with no curiosity about life’s history. That they were nothing but code breakers, riddle solvers, and engineers. The questions and answers offered now by the recognition of the archaea, he said, should go far to revivify evolutionary thinking, and “hopefully divert biology to some extent from its present course of technological adventurism.” By that odd phrase, “technological adventurism,” he seems to have meant not just high-tech molecular biology for its own sake, without regard for evolutionary questions, but also perhaps gambits in genetic manipulation. It was a condemnation so damning and prescient, this whole 1981 rant, that you might imagine he had foreseen gene patenting, the growth of the biotech industry, gene-editing therapies, preimplantation screening of human embryos, and full-on human germline engineering. He set this “technological adventurism” against “molecular evolutionary biology,” his ideal, but an unspoken phrase, which at that time would have seemed oxymoronic.

      That’s the notable takeaway from his 1981 Munich talk: it reflects Carl Woese’s compulsion to dig ever deeper into