Quanta's "The Dirt That Refused To Die" follows a French lab that sterilized soil with gamma radiation, sealed it in jars, and watched it keep breathing — taking in oxygen and giving off carbon dioxide for six years, with no living cell left inside. The researchers argue they're seeing metabolism without life: the reactions of the Krebs cycle ticking over in dead dirt, maybe the way they did before the first cell existed.
"It's the chemistry of geology," says University of Ottawa chemist Joseph Moran, who wasn't involved. The experiments, he says, show "what happens to biomolecules when they're left to their own devices." Biochemist Markus Ralser isn't surprised: "If it would be very hard to do, then the planet would not be full of life now."
Clémentin Bouquet, who co-led the work, says he likes "to imagine the survival of processes that may predate life itself, right there under our feet."
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