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There are fewer microbes out there than you think
August 28, 2012 9:01 AM   Subscribe

There are fewer microbes out there than you think. New estimate reduces the number of microbes on Earth by around half.

Current consensus:
Kallmeyera J, Pockalnyc R, Adhikaria RR, Smith DC, & D’Hondtc S. 2012. Global distribution of microbial abundance and biomass in subseafloor sediment. in press - doi: 10.1073/pnas.1203849109. [ABSTRACT] [FULL TEXT PDF]

Previous consensus:
Whitman WB,Coleman DC, & Wiebe WJ. 1998. Prokaryotes: The unseen majority. PNAS 95(12): 6578-6583 [FULL TEXT HTML] [FULL TEXT PDF]



Related:
Slo-mo microbes extend the frontiers of life
Community in the deep seabed uses so little oxygen that it is no longer clear where the lower bound for life lies.

Geomicrobiology: Low life
The boundaries of biology reach farther below Earth's surface than scientists had thought possible. Amanda Leigh Mascarelli delves into how microbes survive deep underground.
posted by Blasdelb (38 comments total) 10 users marked this as a favorite

 
Interesting! The idea that geomicrobiology is an actual field is kind of blowing my mind right now.

Also: fuck yeah, microbes!
posted by Doleful Creature at 9:06 AM on August 28, 2012


I'm pretty sure this is because I got a puppy and every time he squirts or poops on the floor, no matter how small, I attack it and everything in a 3' radius with a clorox wipe. You're welcome, earth.

PNAS
tee-hee!

posted by phunniemee at 9:07 AM on August 28, 2012 [3 favorites]


There are fewer microbes out there than you think.

THIS IS FUCKING BULLSHIT
posted by Greg Nog at 9:12 AM on August 28, 2012 [5 favorites]


no NO NO NO NO
posted by MangyCarface at 9:12 AM on August 28, 2012 [2 favorites]


I read somewhere that there may actually be more life (going by pure tons of biomass) on Mars than on Earth, because geological conditions there - heat, density, and so forth - are more amenable to these giant deposits of deep-underground microbes.

Any xenobiologists out there, please tell me I'm not totally full of shit
posted by theodolite at 9:14 AM on August 28, 2012 [1 favorite]


Any xenobiologists out there, please tell me I'm not totally full of shit

Not full, going by pure tons of biomass.
posted by DU at 9:16 AM on August 28, 2012 [10 favorites]


To my inferior brain this is like the talk about different kinds of infinity. It's THIS times ten to the 29th power rather than THAT times ten to 29th power. Any number bigger than one time ten to the 29th is just super super crazy big.

Anyway it's still all just models. I'm an empiricist, call me when they count 'em!
posted by nanojath at 9:16 AM on August 28, 2012


Maybe they are too small to see and count, that's why they call them microbes.
posted by Xurando at 9:17 AM on August 28, 2012


"no NO NO NO NO"

This confuses me
posted by Blasdelb at 9:19 AM on August 28, 2012 [1 favorite]


So there's a chance that Freemasons don't rule the country?
posted by griphus at 9:23 AM on August 28, 2012 [1 favorite]


This confuses me.

Those microbes had a family, man!
posted by phunniemee at 9:23 AM on August 28, 2012 [2 favorites]


I read somewhere that there may actually be more life (going by pure tons of biomass) on Mars than on Earth, because geological conditions there - heat, density, and so forth - are more amenable to these giant deposits of deep-underground microbes.

I've always wondered why we spend so much time looking for life on other planets when it seems plausible that we could just introduce an extremophile or chemoautotroph to another moon or planet and possibly grow/produce new life there. I can't be the first to wonder this. Anyone care to comment?
posted by Demogorgon at 9:25 AM on August 28, 2012 [1 favorite]


Those microbes aren't gone. They're in hiding.
posted by delfin at 9:26 AM on August 28, 2012


So we're at Peak Microbe? Who the hell do we go to war with to solve this?
posted by hincandenza at 9:28 AM on August 28, 2012 [2 favorites]


Anyway it's still all just models. I'm an empiricist, call me when they count 'em!

On the ground is a pile of microbes.

>count microbes

There are 69,105 microbes here.


Now you just have to multiply by the number of piles.
posted by delfin at 9:29 AM on August 28, 2012 [6 favorites]


it seems plausible that we could just introduce an extremophile or chemoautotroph to another moon or planet and possibly grow/produce new life there.

You might experience a little blowback from some people on that plan. And what would it accomplish anyway? You won't terraform the planet in any reasonable time. If you just want to know if the microbe will live there, why not just try it here under similar (simulated) conditions? A lot easier to track the progress.
posted by DU at 9:32 AM on August 28, 2012


Canadian social media suggests there are just four.
posted by MuffinMan at 9:38 AM on August 28, 2012


You might experience a little blowback from some people on that plan. And what would it accomplish anyway?

Well yeah, the blowback is reasonable and expected. But what would you accomplish? Why, you get to play God, of course.
Seriously though, I don't know. I guess part of the fun would be finding out what you could accomplish. I guess you might also increase the chance of extending biological life beyond Earth. Whether that is an ethical or worthwhile endeavor is a matter of opinion, I guess.
posted by Demogorgon at 9:47 AM on August 28, 2012


"I've always wondered why we spend so much time looking for life on other planets when it seems plausible that we could just introduce an extremophile or chemoautotroph to another moon or planet and possibly grow/produce new life there. I can't be the first to wonder this. Anyone care to comment?"

Well, Mars for example is really really extreme.

Life as we have found it so far on Earth absolutely requires liquid water to function and there is none on the surface of Mars, it is way too cold. Microbes can live in pockets of water in seemingly solid ice below 0°C so long as it can make anti-freezes that disrupt ice crystal formation, it can exist in suspended animation indefinitely if frozen cold enough, it can exist in temperatures above 100°C so long as there is enough pressure to keep the water liquid, it can exist without detectable salt and at the saturation point of salt in water, but it has never been found to exist without liquid water. There isn't anything we know that would have a snowball's chance in hell of doing anything but waiting on Mars.

Similarly, none of the moons in our solar system have ever been found to have liquid water either, if only because they are either too hot or too cold, though there has been interesting speculation about planets outside of our solar system.
posted by Blasdelb at 9:47 AM on August 28, 2012


Life as we have found it so far on Earth absolutely requires liquid water to function

Hmmm...I guess as an immunologist I should have known this, but I guess I had banked on the idea that there might be some crazy microbe that doesn't require water. Makes sense, considering we are always hearing about astronomers looking for planets with liquid water.
posted by Demogorgon at 9:54 AM on August 28, 2012


I guess part of the fun would be finding out what you could accomplish.

If I could launch my own rockets, I would totally have done this by now. But I think you are going to have trouble getting massive funding for a project where the goal is literally "let's see what happens".
posted by DU at 9:57 AM on August 28, 2012 [3 favorites]


I've always wondered why we spend so much time looking for life on other planets when it seems plausible that we could just introduce an extremophile or chemoautotroph to another moon or planet and possibly grow/produce new life there.

Because finding life on another planet would be really, really cool. Partly because it just self-evidently would be, but also because studying that life would answer some fascinating questions about life here on earth. Would be be based on DNA, RNA or anything remotely similar? Would it use proteins and, if so, what amino acids would it be based on? Same questions for carbohydtrates and lipids. Finding that aspects of life on another planet look a lot like us would hint that there's a good reason that life as we know it is based on this particular set of chemistry, and understanding that reason would tell us a lot about how life got started here on earth. Or it could be that the chemistry we're based on is nothing special after all, and we find something radically different. New generations of biologists can spend their lives understanding, and then, later, biotech people can put to completely unpredictable applications.

As for "why not introduce something", if it worked it would contaminate environments that we want to study, to learn about the history of those bodies and of the solar system as a whole. It could also, in a rabbits-in-australia sort of way, endanger any pre-existing life that we'd want to know about. There's actually an international treaty to this effect: everything that has ever touched Mars, for example, was carefully sterilised here on earth before being sent out for exactly this reason.

I guess I had banked on the idea that there might be some crazy microbe that doesn't require water
Yeah, water is quite special (fairly inert, fantastic solvent, etc) but deep down I do believe that in a big enough, old enough universe, there must be *something* like that. I wonder if we'd ever actually spot it, though? We can't culture most of what grows in seawater, and only know that it exists thanks to just blindly sequencing whatever DNA we can find; if we're talking about sulphur and oil-based lifeforms, or self-propagating turbulence patterns in the bottom of a gas giant somewhere, I can't imagine how we'd ever discover it.
posted by metaBugs at 10:05 AM on August 28, 2012 [2 favorites]


Oh, I was wondering where they were.
posted by ricochet biscuit at 10:09 AM on August 28, 2012


Hang on, did some evil wizard make the microbes wear differently coloured hats?!
posted by fallingbadgers at 10:20 AM on August 28, 2012


I didn't mean to make it sound like we have to introduce terran species to other planets at the exclusion of continued exploration and discovery. We can still do both at the same time.
metaBugs, wouldn't many of the same benefits you describe to discovering new life on another planet also be applicable to the introduction of life there? And yes, we would have to assume that introducing an organism would bring about the extinction of native species. Still, I say shoot our life missiles all over the place. See what happens. I bet if we had a bacteria that we knew could convert Mars dust into oil we'd have had it there a decade ago.
posted by Demogorgon at 10:53 AM on August 28, 2012


This is interesting news about microbes, but what about the regular bes?
posted by samofidelis at 11:08 AM on August 28, 2012 [2 favorites]


Similarly, none of the moons in our solar system have ever been found to have liquid water either, if only because they are either too hot or too cold, though there has been interesting speculation about planets outside of our solar system.

Cassini has apparently revealed liquid water volcanoes on Titan, and a liquid water layer under the ice there is also thought to be highly probable.
posted by jamjam at 11:19 AM on August 28, 2012 [1 favorite]


Proceedings of the National Academy of Sciences tip: always pronounce it "Pee-Enn-Aye-Ess," because once I asked my boss if she'd the new awesome peenas thing



WELP
posted by samofidelis at 11:57 AM on August 28, 2012 [4 favorites]


What is the only thing worse than a mecium?
A paramecium.

Why do bacteria like nitrates so much?
They're cheaper than day rates.

What do you get when you cross a rabbit with an amoeba?
An amoebit. It can multiply and divide at the same time.

/splits
posted by prinado at 1:42 PM on August 28, 2012 [3 favorites]


Well, now I'm starting to think my microbe dating website was a bad idea!

Happy now, dad?!
posted by orme at 2:35 PM on August 28, 2012 [1 favorite]


This is a bigger deal than it may seem on first blush, because it has implications for the Carbon Cycle - and thus, affects all life on Earth.

I dunno exactly what it means, but fewer microbes in the sediment probably implies that there is less carbon locked up down there than we may think.
posted by Kevin Street at 3:31 PM on August 28, 2012


I will do my part to encourage microbe production by leaving the dishes in the sink tonight.

You're welcome.
posted by BlueHorse at 4:59 PM on August 28, 2012 [1 favorite]


Antipathy towards the transport of earth based microbes to other planets seems to derive from some sort of anthrocentric viewpoint. The existence of a species capable of building a machine that can transport the microbes seems as random as say, a meteorite slamming into the earth and blasting a few microbes out there.
posted by area45 at 7:51 PM on August 28, 2012


woah, totally panicked after mis reading microbes as microbrews...
posted by evilelf at 8:03 PM on August 28, 2012 [1 favorite]


I don't think it's anthropocentrism, it's the well-founded belief that if there's any chance that we introduced bacteria to Mars, any subsequent claims of newly-discovered life there would be suspect. And even if we expected to find herds of roaming multicellular thingoids, which we don't, it would seem to be good practice to avoid contaminating other planets.
posted by sneebler at 6:58 AM on August 29, 2012 [1 favorite]


Demogorgon -
I didn't mean to make it sound like we have to introduce terran species to other planets at the exclusion of continued exploration and discovery. We can still do both at the same time.
At least for the moment, we don't have that many planets in reach. If we did manage to seed life on one of them, any subsequent discovery of "alien" life in that environment would be suspect, especially if it looked a bit like us at the molecular level. For a given planet, we should satisfy ourselves that there's no life (proving a negative, woo!) and then talk about introducing life.
metaBugs, wouldn't many of the same benefits you describe to discovering new life on another planet also be applicable to the introduction of life there?
Well, perhaps some. All (known) life on earth is based on the same building blocks: most of the functionality of the cell comes from a population of proteins, which are made from a set of 20 amino acids that's common to all life, which are built using a length of RNA (always made of nucleotides A,C,U&G**) as a template, which was copied from DNA (always made of ACT&G) in a B-form double helix. We don't really know why any of this is so; is there some chemical/physical reason why these molecules and these arrangements of molecules are the foundation of life on earth? Are they really the best options for stability, structural diversity (for both information-carrying and mechanism-building purposes), etc by a wide margin? Or is it just a fluke, and if a particular rock had splashed into a different puddle all those aeons ago, could life on earth just as easily have had a completely different basis?

Sending examples of life from earth to other planets will tell us about how familiar, earth-evolved life adapts to extreme conditions, which is undeniably interesting. But finding life that has evolved completely separately, perhaps under different (but known) conditions, could give us some hints about the universality, or not, of biochemistry, and therefore towards our own origins.

I'll admit, though, that my first comment employed the usual scientist's appeal to deliberately vague possible applications of the knowledge, while really all I care about is the knowledge itself. We probably could get some useful stuff out of successfully seeding life on other planets and letting it evolve in weird conditions, but it won't address the really fascinating questions. I guess it's my equivalent to the CERN fans going on about the Web, or NASA about Teflon: I have no clue what would come out of answering these deep questions, but I think that chasing this knowledge for its own sake is a worthy project for us as a species, and know from history that big jumps in our understanding occasionally result in the invention of some useful toys.

So you're probably right, but it causes me great pain to admit it :).

sneebler said it nicely, IMO. Even if we decide that scientific curiosity and (admittedly very sketchy) economic arguments aren't enough, I still think we should be careful because "don't destroy ecosystems" just seems like a good rule of thumb. Admittedly, this could say more about my biases as a biologist than about what's actually good for us as a species.

*This is somewhat over-simplified and, biology being what it is, there are all sorts of edge cases and caveats to this. Further, if you relax your definition of "life" to include viruses, transposons, prions, etc (inert on their own, but contain signals and mechanisms that cause cells to make copies of them), then things can go a bit crazy. But every form of cellular life makes proteins from the same building blocks, based on an RNA template, based on DNA.

**OK, almost always.

posted by metaBugs at 7:56 AM on August 29, 2012 [2 favorites]


I am not sure that the smaller number of microbes is a problem ;-)
After all, there seems to be more inside us than we thought....
posted by MessageInABottle at 8:04 AM on August 29, 2012 [1 favorite]


Reduction by half still means they outnumber eukaryotic cells by a few orders of magnitude.
posted by CBrachyrhynchos at 6:24 AM on September 4, 2012


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