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Sputnik News reports that researchers are finding a "subterranean Galapagos" including "creatures such as microbial life thriving at 121 degrees Celsius or 'zombie bacteria', which can reproduce or live for millions to tens of millions of years."

In a recent 700-page book called "Carbon in Earth", in chapter 17 "Nature and Extent of the Deep Biosphere", Frederick S. Colwell and Steven D'Hondt write:

Given the extraordinarily low rates of microbial respiration in many subsurface environments, subsurface microbes are generally assumed to reproduce very slowly, if at all. D'Honda et al. (2002a) speculated that most subseafloor sedimentary microbes are either inactive (dormant) or adapted for extraordinarily low metabolic activity. Price and Sowers (2004) suggested that subsurface sedimentary microbes exhibit survival metabolism (sufficient to repair macromolecular damage but insufficient to sustain growth or motility). Whether they are actually growing or merely repairing macromolecular damage, amino acid racemization ratios indicate that subseafloor sedimentary biomass turns over very slowly, on timescales of hundreds to thousands of years (Lomstein et al. 2012). We do not yet know whether the microbes of these subsurface environments reproduce at these slow rates of biomass turnover or live without dividing for millions to tens of millions of years.

P. 559

Is this possible? Could "Zombie" cells have been alive for millions or tens-of-millions of years "without turnover"?

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elliot svensson
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    From your quote: **We do not yet know whether the microbes of these subsurface environments reproduce at these slow rates of biomass turnover or live without dividing for millions to tens of millions of years** – Bryan Krause Dec 12 '18 at 17:28
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    As a more general question, what it means for "how long" a single-cell organism lives is a matter of perspective. Life has been around billions of years, as long as you choose the correct daughter cell at each division the first life to be alive is still alive today. That isn't the same as life expectancy or the life span of multicellular organisms, which have a more clear life cycle. – Bryan Krause Dec 12 '18 at 17:31
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    They didn't say _direct lineage_ but "without dividing"... they are talking about an individual cell that's still alive after all that time! – elliot svensson Dec 12 '18 at 17:33
  • I know, I was referring to your broader question. Still, I see nothing to be skeptical about: see my first comment please. – Bryan Krause Dec 12 '18 at 17:37
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    @Giter, I'm not convinced that the Sputnik writers are in disagreement with the book... they say that "X can live millions of years", while the book says "We do not yet know whether the microbes [option 1] or if they live _without dividing_ for millions of years" (paraphrased). – elliot svensson Dec 12 '18 at 18:07
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    Of course using them the term *zombie* is just clickbait. And isn't this just a a question for [Biology.se]? –  Dec 14 '18 at 14:09
  • An article in Scientific American from 2-3 months ago describes exactly this: very slow living micro-organisms embedded in the deep sea floor. I do not have it at hand right now. –  Dec 14 '18 at 14:14
  • The clickbait title forms part of the tenuous claim... without endorsing it, we respond to it directly. – elliot svensson Dec 14 '18 at 17:16

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