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Tracking Down the First Oxygen Users

sciencehabit writes "None of us would be here today if, billions of years ago, a tiny, single-celled organism hadn't started using oxygen to make a living. Researchers don't know exactly when this happened, or why, but a team of scientists has come closer than ever before to finding out. They've identified the earliest known example of aerobic metabolism, the process of using oxygen as fuel. The discovery may even provide clues as to where the oxygen came from in the first place."

19 of 109 comments (clear)

  1. Where the oxygen came from... by jeffmeden · · Score: 4, Insightful

    The discovery may even provide clues as to where the oxygen came from in the first place.

    Shouldn't they be looking for the carbon dioxide eaters?

    1. Re:Where the oxygen came from... by SJHillman · · Score: 5, Informative

      We already know the guys who produced the oxygen (or at least we have a good idea), we're interested in the ones who used it.

    2. Re:Where the oxygen came from... by Anne_Nonymous · · Score: 2

      Look hard enough and you'll find an ancient civilization who built forests of artificial CO2 sequestering trees.

    3. Re:Where the oxygen came from... by turbidostato · · Score: 5, Informative

      "My understanding ... is that atmospheric oxygen at levels high enough to sustain oxygen based metabolism came from plants and trees"

      Your understanding is quite wrong.

      By the time there were "plants and trees" the major part of the biosphere already was oxigen dependant.

      The change of the atmosphere from reductive to oxidative predates trees by about two billion years -the start of the proterozoic age is marked about 2.4 billion years ago (with a strong spike around the precambric which still predates trees by about 300 million years).

    4. Re:Where the oxygen came from... by The+Grim+Reefer · · Score: 3, Interesting

      "My understanding ... is that atmospheric oxygen at levels high enough to sustain oxygen based metabolism came from plants and trees"

      Your understanding is quite wrong.

      By the time there were "plants and trees" the major part of the biosphere already was oxigen dependant.

      The change of the atmosphere from reductive to oxidative predates trees by about two billion years -the start of the proterozoic age is marked about 2.4 billion years ago (with a strong spike around the precambric which still predates trees by about 300 million years).

      It's my understanding that cyanobacteria is responsible for initially creating earths oxygen. I can't say I know much about the historical aspect of it. But I used to keep saltwater reef/fish tanks, and it can become a big problem if you do something wrong. It's really nasty slimy algae looking stuff. I used to find in ironic how much many fish keepers despised the stuff, and yet we probably wouldn't be here without it.

    5. Re:Where the oxygen came from... by Anonymous Coward · · Score: 2, Funny

      Simple. The first oxygen users should have low ID's.

    6. Re:Where the oxygen came from... by na1led · · Score: 2

      It all happend about 6,000 years ago. God spit out Air, Plants, Animals, and Humans, all at once, and you can't convince me otherwise!

      --
      -- By all means let's be open-minded, but not so open-minded that our brains drop out.
    7. Re:Where the oxygen came from... by djl4570 · · Score: 3, Informative

      Cyanobacteria changed the chemistry of the oceans as well. Before oxygen production the oceans contained large quantities of dissolved iron. When oxygen was produced the dissolved iron oxidized and precipitated out as rust. The banded iron formations are a relic of this epoch. It wasn't until the oceans reached equilibrium between oxygen and iron that surplus oxygen was released into the atmosphere.

  2. Oxidizer, not fuel by Un+pobre+guey · · Score: 5, Informative

    Oxygen is not the fuel. It is the oxidant to the fuel to release energy.

    1. Re:Oxidizer, not fuel by Aguazul · · Score: 5, Insightful

      In a hydrocarbon atmosphere, you can burn oxygen. All our definitions are oriented around our oxygen-based atmosphere. I'm sure we'd call oxygen 'fuel' if we lived in a hydrocarbon atmosphere and oxygen was the scarcer material.

    2. Re:Oxidizer, not fuel by Em+Adespoton · · Score: 2

      After all, no matter how you present it, it's just a chemical reaction: 2 molecules and some energy. "Fuel" and "fire" and "burn" are all just lies to children. Either that, or Iron is also a "fuel" with an end result of "rust" ash. Low "burning" temperature, and low heat output, as it doesn't take much for Iron to react with oxygen.

    3. Re:Oxidizer, not fuel by K.+S.+Kyosuke · · Score: 3, Interesting

      In a hydrocarbon atmosphere, you can burn oxygen. All our definitions are oriented around our oxygen-based atmosphere. I'm sure we'd call oxygen 'fuel' if we lived in a hydrocarbon atmosphere and oxygen was the scarcer material.

      Which made a wonderful plot for Isaac Asimov's lovable The Dust of Death :) You can tell the guy was a chemist. ;-)

      --
      Ezekiel 23:20
    4. Re:Oxidizer, not fuel by idontgno · · Score: 2

      Interesting point. On a geologic timescale, "rust" is a flash fire.

      Still, colloquial English words are based on current human experience of time and matter. Even an ember flashing to fire in a pure-oxygen atmosphere, the ember is considered fuel, even if it's outmassed by the oxygen available for the reaction.

      Also, from a chemical perspective, in most chemical reactions involving oxygen, oxygen is the oxidizing agent and the other element or compound is the reducing agent. (Maybe all? I can't think of any redox reactions with oxygen as the reducer, but chemistry was decades ago.)

      So, in summary: the distinction between fuel and oxygen can't be inverted.

      --
      Welcome to the Panopticon. Used to be a prison, now it's your home.
    5. Re:Oxidizer, not fuel by Megahard · · Score: 4, Informative

      While "oxidation" is lexically derived from oxygen, there's a specific chemical definition for oxidation, namely the loss of electrons. LEO GER is the acronym beginning chemists learn. So while you can play around with the words the chemistry is well-defined. Oxygen is the oxidant because it transfers elections to the reductant or fuel or whatever you want to call it.

      --
      I eat only the real part of complex carbohydrates.
    6. Re:Oxidizer, not fuel by mcgrew · · Score: 4, Informative

      "Fuel" and "fire" and "burn" are all just lies to children.

      Not lies to children, but the obvious. Of course, what may seem obvious often isn't ("the world is flat"). You and I know that if you combine a piece of wood and oxygen, both are converted, but you have to know how it works first. But at any rate, "fire" is a synonym of "oxidation". Fire is what you get when you combine a combustable material, oxygen, and heat. It's real, it's no lie. The combustable material is the fuel, oxygen is the oxident, and "burn" is the conversion of the fuel and oxygen to a different form. It's semantics, not lies.

      Either that, or Iron is also a "fuel" with an end result of "rust" ash.

      Actually, rust is steel's ashes, and you can make steel burn quite fast of you get it hot enough; ask any blacksmith. You can make sparklers out of pieces of wire coat hangers or bailing wire, coated with saltpeter mixed with flour or sugar. The sparkles on any sparkler you buy at a fireworks stand is the steel's flames, and that's exactly what you see if you put a thin piece of steel in a forge with the bellows going. Take the steel out of the fire and it sparkles like a sparkler, and leaves rust behind.

    7. Re:Oxidizer, not fuel by rubycodez · · Score: 2

      no chemistry in you background, I take it. there are plenty of other gases that support combustion, fluorine is one. You could burn fluorine on your hydrocarbon atmosphere planet, or hydrocarbons on a fluorine atmosphere planet. You might be interested to know a rocket with highest specific impulse burns lithium and fluorine. You can make fire with many, many things and not have a molecule of oxygen in sight.

    8. Re:Oxidizer, not fuel by Samantha+Wright · · Score: 5, Interesting

      Oxygen is the most aggressively electronegative element after Fluorine. (I think that Neon might be even more aggressive if you could ionize it usefully.) I had a colourful mnemonic for this in second-year organic chemistry that revolved around bitches and gimps, but the take-home message is that Chlorine robs Nitrogen, and Oxygen wipes out everything but good ol' Fluorine. For related reasons, fluorine becomes a source of face-melting death in hydrogen-bonded form.

      --
      Bio questions? Ask me to start a Q&A journal. Computer analogies available for most topics!
  3. Doxygen? by Anonymous Coward · · Score: 2, Funny

    I read "Tracking down the first doxygen users".

  4. At some levels... by forkfail · · Score: 4, Interesting

    ... the human race shares certain critical traits with these little guys.

    Like them, we're creating a cataclysmic event in the biosphere that will probably wipe ourselves out, but allow the next generation of life to thrive.

    Unlike them, we out to be able to mitigate the impact of our presence, but while we're smart enough to see what we are doing, we don't have the fortitude to change our ways.

    --
    Check your premises.