The Vent At The Beginning: A Battery Made Of Rock

Black smoker hydrothermal vents were found in 1977 on the Galápagos Rift by the Alvin submersible team, including John Corliss and Jack Dymond of Oregon State University, and the first high-temperature black smokers were found at 21 degrees north on the East Pacific Rise in 1979. What made them famous was not the plumbing but the ecosystems: bacteria and archaea oxidising hydrogen sulphide, hydrogen and methane, feeding food webs of giant tube worms, clams, shrimp and crabs. LIFE THAT EATS CHEMISTRY RATHER THAN SUNLIGHT. That is what made vents look like a plausible cradle in the first place.

The force of Russell's argument is not the chemistry, it is an observation about all life. Chemiosmotic energy coupling is universal: bacteria, archaea, and the mitochondria and chloroplasts inside every complex cell all run on a proton gradient across a membrane. His point is that this is best explained if life began somewhere that already had one, and alkaline vents provide exactly that. Nick Lane and William Martin formalised the thermodynamics in Cell in 2012, showing that hydrogen plus carbon dioxide going to organics is favourable under alkaline vent conditions at moderate temperatures.

Günter Wächtershäuser, a Munich patent attorney and origin-of-life chemist, proposed in 1988 that the first metabolic cycles ran on iron-sulphide mineral surfaces, with iron sulphide plus hydrogen sulphide going to pyrite and releasing reducing power. Claudia Huber and Wächtershäuser then demonstrated peptide bond formation on nickel-iron sulphide surfaces at 100 degrees and pH 7 to 10.5, in Science in 1998. The supporting observation is as good as Russell's: iron-sulphur clusters sit in the active sites of ferredoxins, hydrogenases, nitrogenases and carbon monoxide dehydrogenase in virtually all life.

Laura Barge and colleagues at the Jet Propulsion Laboratory made alanine and other amino acids in simulated alkaline vent chimneys, using iron oxyhydroxide minerals, pyruvate and ammonia at 70 degrees, published in PNAS in 2019. Hudson and colleagues showed in 2020 that formaldehyde produced by carbon dioxide reduction can undergo the formose reaction under simulated vent conditions to give sugars including ribose, which is the sugar in RNA. OUR FILE CALLS HER LAURIE BARGE. THE RECORD SAYS LAURA.

A 2016 study identified 355 genes likely present in the Last Universal Common Ancestor and described an anaerobic, hydrogen-dependent organism using the Wood-Ljungdahl carbon fixation pathway, which is what you would expect of something living at an alkaline vent. One detail about the attribution: our file's summary calls this a study by William Martin and colleagues. Martin is the senior author. THE FIRST AUTHOR IS MADELINE WEISS, and our file's own bibliography names her correctly even where its summary does not.

The largest hole is the step from a free gradient to a paid one. How life moved from depending on a geological proton gradient to generating its own, with membrane-bound electron transport chains, is unsolved. Lane and Martin propose early protocells with leaky lipid membranes inside vent pores, gradually evolving ion-tight ones. Our file's own word for the detailed mechanism is HYPOTHETICAL, and it puts the whole transition in its speculative section rather than its verified one.

Our file prints them rather than burying them. The RNA World and warm-pond models, favoured by Jack Szostak and John Sutherland, depend on ultraviolet-driven photochemistry and wet-dry cycling to make nucleotides, and NEITHER CONDITION EXISTS AT THE BOTTOM OF THE SEA. Concentration is a real problem: vent fluids are extremely dilute, and the mechanisms for concentrating prebiotic molecules to reactive levels inside vent pores are not fully demonstrated. And Sutherland argues in Angewandte Chemie that the chemistry of life's building blocks points at surface photochemistry rather than deep-sea reduction.

Our file does not refuse the warm pond. It keeps Darwin's warm little pond and Miller-Urey spark chemistry as relevant. What it refuses is the claim that life could ONLY have started at the surface under ultraviolet light, which it says is contradicted by the thermodynamics of vent chemistry and by the phylogenetic evidence for a thermophilic, anaerobic ancestor. THE REFUSAL IS AIMED AT AN EXCLUSIVITY CLAIM AND NOT AT A RIVAL HYPOTHESIS, which is a distinction most files in this library do not manage to make.

All five identifiers this file carries resolve exactly, matching author, title, journal, volume, issue, pages and year in every case: Russell 1993, Martin and Russell 2003, Lane and Martin 2012, Kelley 2001 and Wächtershäuser 1988. Nine further entries carried no identifier at all, and EIGHT OF THEM WERE FOUND, every single one an accurate citation missing only its pointer. THIRTEEN OF FOURTEEN ENTRIES VERIFIED CORRECT. The fourteenth is a 2015 trade book with no identifier to find, recorded here as unchecked rather than clean.

Here is the first entry as it actually sits in the file, field by field: "Russell, Michael J., Roy M" then the year, then the title, then the journal, then the page range, THEN "Daniel, and Alan J", then the identifier, THEN "Hall". That is one author list, Russell, Michael J., Roy M. Daniel, and Allan J. Hall, CUT AT THE FULL STOP AFTER EACH MIDDLE INITIAL and scattered across three separate columns, one of them arriving after the DOI. The same break splits William F. Martin in another entry, Michael J. Russell in another, Dennis K. Bird in a fourth, and turns the publisher W. W. Norton into "New York: W" and "W; Norton" in a fifth. FIVE OF FOURTEEN ENTRIES. ONE MECHANISM. NOT ONE WRONG CITATION AMONG THEM.

Every previous file in this series produced bad content: a pointer aimed at the wrong work, a locator that had drifted, a paper nobody could find. THIS ONE'S CONTENT IS ESSENTIALLY PERFECT AND ITS MACHINERY IS BROKEN. Those are different defects and they need different repairs. A field parser that breaks on a middle initial is an afternoon's work and it would fix five entries at once. A citation pointing at the wrong paper has to be found and re-resolved one at a time. Fifteen articles into this audit, this is the first document where the two come cleanly apart.

The Barge paper's first author is Laura M. Barge, not Laurie, in both the prose and the bibliography. The 1993 Terra Nova paper's third author is Allan J. Hall, not Alan, and the thing that proves it is the correct identifier our file itself supplies. And the Sutherland paper is dated 2016 in the bibliography and 2017 in the counter-arguments section: the record puts it in volume 55, issue 1, of Angewandte Chemie International Edition, which is the January 2016 issue, so THE BIBLIOGRAPHY IS RIGHT AND THE BODY IS WRONG. That is the second time in this series that a file's bibliography has been the more reliable half of the same document.