The Genesis Quest: The Geniuses and Eccentrics on a Journey to Uncover the Origins of Life on Earth by Michael Marshall. University of Chicago Press, 2020 (ISBN: 9780226715230)
The Genesis Quest is a tour-de-force recount of the eclectic effort to understand the origins of life on Earth, authored by science writer Michael Marshall. Here is a tale that spans from prebiotic chemistry to protocells, interlaced with stories of the idiosyncrasies of the scientists involved. It's a union of the sciences – synthetic chemistry, astrobiology, biochemistry, microbiology, ecology. Much like the primordial polymer blob "coacervates" that coalesce into one, discussed early in the book, famous names in science quickly become associated with personality and foibles, putting more than just a face to the names.
The book is divided into four sections. The first begins with the early experiments: the famous "Primordial Soup Hypothesis" from Oparin and Haldane, the sparking of prebiotic molecules into test-tube existence à la Miller and Urey, and the chemical synthesis of ATP under possible early Earth conditions. This historical period sees the onset of the Achilles-heel question for many a chemical synthesis between then and now: But is it prebiotically plausible? In this section are also spotlights of figures in microbiology, both well-known names like Pasteur and Virchow as well as the sidelined Robert Remak, whose ideas were snatched and popularized by Virchow in his pithy 'Omnis cellula e cellula'…
The next section overturns the 1950s' simplistic focus on isolated molecules. With the structural and functional explorations of DNA, from crystallography to the triplet code, life turned out to be much more complex. Here, Marshall acquaints readers with the iconoclastic character Cairns-Smith, who, to the scoffs of his contemporaries, proposed that crystals divide, pass on inherited traits, and evolve. Biomolecules came together in the scaffolding provided by clay crystals, Cairns-Smith urged, and when these "mother" crystals crack, they pass on their physical properties to the resulting "daughter" crystals. Despite the clay hypothesis's faults (pun intended), here was the first instance of the notion that "life is about information that is inherited imperfectly." A bit of biological poetry.
The characters in this origins-of-life yarn are of course bull-headed scientists. The third section moves into a consideration of the 1980s' four major points of contention. First, which essential function of life came first: replication, compartmentalization, or metabolism? Second, which molecular building block of life came first: RNA or proteins? Third, where on Earth did life arise? And finally, in what organisms were the answers to these questions kept under genomic lock and key? Pages in this section dive into a seafaring storytelling of hydrothermal vents as the possible cradle of life (the consensus now agreeing that the gentler, alkaline "white chimneys" are a more likely candidate than the scorchingly hot "black smokers"; see a related STC post on serpentinization here). Here is also a contrasting consideration of landmass-based origins of life. Perhaps the wellsprings of life were instead hot springs and geothermal ponds.
The fourth and final section is the story of such ideological rifts on the mend. By the early twenty-first century, the prevailing hypotheses were the "replication-first camp" with its RNA World, the "compartmentalization-first camp" with its lipid-based protocells, and the "metabolism-first camp" with the proton gradients of alkaline vents. The everything-first reconciliation came in the form of Szostak's protocells. These are RNA-containing bilayer membrane vesicles that can grow, divide, and undergo Darwinian selection, thereby merging the RNA World with compartmentalization. The wall between genes-first adherents and metabolism-first devotees crumbles apart as well: "information and entropy are two sides of the same coin," exemplified by Maxwell's demon.
But Marshall writes, the first cell was not alone and was rather part of a community. The rise of cells can therefore be better understood through the lens of ecology and community dynamics. The final pages of the book see a union of seemingly far-flung fields like chemistry and population ecology, much like the union of different origins-of-life hypotheses. No cell – nor protocell – is an island.
Overall, The Genesis Quest paints the story of Origins research as a funky one. Both the trajectory of science and of the people were often full of bizarre contradictions and non sequiturs. "Geniuses and Eccentrics," from the book's subtitle, is certainly an apt and pithy summary. Although I began familiar with a number of the landmark Origins experiments, I had known very little about the people behind them and I delighted in these backstories: from the influence of political slants on scientific thought, as in the Oparin and Haldane duo and communism and dialectical materialism, to the scientific heretics who sparked outrage from the mainstream origins-of-life bigshots (and were often off from reality by a long shot), but propelled important concepts into debate. In addition to Cairns-Smith, there was Wächtershäuser and his Iron-Sulfur World Hypothesis, with the key idea that life needed an energy source from the get-go.
These backstories were often a blend of serendipity and science communication, as in the case of Stanley Miller, whose career began when he stumbled into a life-changing lecture by Harold Urey, and John Sutherland, who years later stumbled in on Albert Eschenmoser's lecture. On the note of serendipity, also peppered throughout is the recurring motif of montmorillonite clay, a seeming cure-all for all origins-of-life experimental ills, from speeding up RNA synthesis to coaxing the correct nucleotide chirality to catalyzing bilayer lipid vesicle formation. Marshall highlights the non-discountable role of chance in discovery.
Finally, I especially appreciated the acknowledgments of the less-pretty aspects of science. Marshall nods at undercurrents of egotism, politics, and implicit and explicit biases, and he also makes a point of spotlighting people who contributed to landmark scientific discoveries but whose names were smothered out of history by those same ills. Tina Negus, for example, discovered the first Precambrian fossil but was brushed aside because she was a girl (the same fossil hailed as a brilliant find when rediscovered by schoolboy Roger Mason a year later). In this storytelling is a wonderful paradox: In digging into the remotely distant past of life, Marshall also writes his way forward, hoping for an optimistic future society. (Regarding his shout-out of Angela Saini's book Inferior in the introduction – here is my enthusiastic agreement that it is a well-researched read on gender biases!). By tracing the messy switchback path that the science has taken, the book gently paints science as flawed and subject to revisions. I found The Genesis Quest to be a depiction of people who are talented and driven but also entirely human, and I found that uplifting.
A bit poetically, the book's first and last chapters open and close with imagery of the "warm little pond" that Darwin proposed. This story of life comes full-circle!