When They Were Cells

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Discussion by: Jigger

Upon the creation of the first living cells (or even if those cells landed here from elsewhere in the cosmos) those cells had to ingest or absorb some kind of life supporting sustenance. If the cells didn't start eating each other right from the start (predator and prey system), and if these cells couldn't absorb nutrients from the ground (a root system) then all that was left for sustenance was water and the sun.

  1. Could a living cell thrive on just oxygen and hydrogen, along with nutrients from the sun?
  2. Are there any life forms today that are surviving on just these three sources?

24 COMMENTS

  1. Cells do not have to have nutrients derived from other living cells. In first year cell biology, college students learn how to make a nutrient solution straight from chemical stocks that will support simple cells. Deep in the oceans there are thermal vents that pump out non-living chemical soups that support whole ecology systems of organisms.

  2. Hi Jigger,

    There were lots of other elements, chemical compounds and abiotic nutrients that were used for assembling simple life and powering reactions in pre-cellular life forms. Cellular life wasn’t created, but evolved from simpler life forms back to the first self-replicators. I’m not qualified on this, but I did find good info by browsing “pre-cellular life” and “pre-cellular nutrients”…. Mac.

    https://www.boundless.com/biology/evolution-of-early-life/the-beginning-of-life/how-the-first-cells-formed/

    http://www.colfinder.net/materials/Green_Teacher/m1/unit_5.pdf

  3. I think you have to ask ~what came before the cell? I rather fancy the pre-cell concept of the auto-catalytic set ~ which is a collection of entities, each of which can be created catalytically by other entities within the set, such that as a whole, the set is able to catalyse its own production [nicked the wording from Wiki]

    Single cell organisms today are extraordinarily complex. The first cellular organisms could not have been THAT much simpler. Sustenance in the pre-cell environment could have been driven by UV light, electricity, thermal energy generated by impacts & tidal forces, geothermal energy, radioactivity etc. ~ ably assisted by the above mentioned catalytic sets. The raw materials would have been drawn from any one of a number of likely early environments containing methane & the like. It seems that free oxygen would have been very rare back then ~ tied up in water & difficult to break down [I think]

    A likely general path to the cell might be:-
    Stage 1: Biological monomers [possibly coated in lipids]
    Stage 2: Evolutionary processes begin which leads to…
    Stage 3: Fragile replicating biological monomers & polymers [which must have had a lipid coating to protect & concentrate]
    Stage 4: The evolution of proper cell wells & merging of various formerly independent components into the cell environment

    The transitions from 2to3 & 3to4 are very difficult to reconstruct as there’s many paths. We might have to wait until we find other life on icy moons etc before we can construct a likely abiogenesis for Earth

  4. The first replicating things did not use oxygen. All the oxygen seems to have come from things like stromatolites – replication organisms that are like rocks that breathe and give off oxygen. There are a few colonies of modern stromatolites around even now.

    • In reply to #4 by Pabmusic:

      The first replicating things did not use oxygen. All the oxygen seems to have come from things like stromatolites – replication organisms that are like rocks that breathe and give off oxygen. There are a few colonies of modern stromatolites around even now.

      Not Quite! There is the separation of water vapour in the upper atmosphere into H2, O, O2 and O3, caused by solar radiation. The Earth is still losing hydrogen into space at the present time, leaving oxygen behind as a heavier molecule. This is a slow creeping process.

      However, the major change to life on Earth was the “Great Oxidation Event” when there was a mass extinction of earlier pre-oxygen life-forms which failed to find new niches, or adapt to an oxygen rich atmosphere and oceans (Ocean surface at first perhaps?).

    • In reply to #4 by Pabmusic:

      There are a few colonies of modern stromatolites around even now.

      Indeed, there is a colony off the Giants Causeway, Northern Ireland

      The YEC heading up the government of NI still think the Giants Causeway is the biblical 6,000 years. Now, on another thread there was a lot of talk about calling these fuckwits, fuckwits. Ridiculing and mocking such asinine anti science beliefs should be par for the course…because such ignorance is faith driven does nothing to excuse such imbecility… undeserved respect, I think not.

  5. There are bacteria that live off the energy in steam vents.
    Life started without photosynthesis. It also started without oxygen.
    IIRC there are bacteria that can exploit almost any energy source.

    If you don’t have any competition, you have at your disposal all the energy that appears in the ocean by non-biological processes. Nobody else is eating it.

    How are we ever going to figure this out? It was a long time ago. There are no fossils. It presumably happened only once or a small number of times. It might require a huge fluke to occur. We will have to make it happen in the lab.

    My guess if we will discover the seeds of life floating around on bodies that periodically crash into earth. That settles the problem of how life arose so fast on earth. But then we will have an even more difficult problem of figuring out how life arose in the galaxy and the universe. My reason is there are so many earthy spores that can survive deep space. Why would they have evolved that?

  6. An obvious and probably insuperable problem in fully working out the origins of life is that it is very unlikely we will ever find much evidence of what happened ie fossils of the very earliest life. I think some of the earliest remains we do know – maybe 3.5 billion years old – are stromatolite cyanobacteria that grew (and still grow at a few locations in Australia!!) in mats that mineralised and so built up rock deposits. And it is even harder to think that there would be intelligible remains of life, or pre-life before cells. So inevitably there will be gaps and speculation.

    As said already, current life can use various energy sources. Organisms that produce their own energy foods (autotrophs) can capture the energy of sunlight (phototrophs) or inorganic chemicals (chemoautotrophs). Cyanobacteria were an early example of phototrophs, taking in carbon dioxide (CO2, carbon and oxygen) and water (H20 ie hydrogen and oxygen) as the sources for making sugar, and using the energy from sunlight to make the sugar – producing oxygen as a by product. Those same organisms – some being the ancestors of green plants – used oxygen to free the energy from sugars (releasing ie recycling the carbon dioxide and water). I think there is evidence that there was very little oxygen in the early Earth atmosphere and that it took some time for phototroph activity – using photosynthesis – to build up to the 20% oxygen we now have (maybe a slow rise starting 3.5 billion years ago with cyanobacteria and reaching 20% 2 billion years ago).

    But going back to the other energy sources, there are still a wide range of bacteria (eubacteria) and archaea (a sort of bacteria but not the same) who obtain energy from chemicals, ie are chemoautotrophs. This includes bacteria at deep sea vents using hydrogen sulphide, but other inorganic material can be used for energy, such as iron, manganese or ammonia (see http://en.wikipedia.org/wiki/Chemotroph). It is thought – maybe a bit more than just speculated – that chemoautotrophs (such as hydrogen sulphide users) developed before phototrophs (such as the blue green / cyanobacteria). Thus it is thought most likely that chemoautotrophs were the first forms of cellular life, maybe of any kind of life.

    By contrast other single cell life, fungi and animals are heterotrophs, ie do not make their own energy foods, but obtain them by eating or otherwise consuming other life forms (or their remains), be they autotrophs or other heterotrophs.

    However, none of these, autotrophs or heterotrophs, only require energy sources as foods. As you say, other nutrients are needed. Phosphorus is needed in the life’s energy carrier, ADP and ATP to allow cells to use the energy from sugars etc. Nitrogen, sulphur, iron and so on are used in various ways, such as in nucleic acids in DNA ie genes, and many proteins.

    So, to turn to your questions (at last!!)

    1) Not really. Phototrophs (eg blue green bacteria, green plants) need only carbon dioxide, water and sunlight to make sugars as their only source of energy. They need oxygen to liberate that energy from sugar. But they also need other elements (nitrogen etc) in using that energy to build their structures.

    2). Again, not really. Phototrophs are mentioned above. But there are chemoautotrophs that do not use carbon based chemicals in energy capture (they of course share the carbon based chemistry of life otherwise).

    We do not know of life that is non-cellular, and though maybe one could not rule out life without cells it is hard to see how otherwise the necessary chemicals could be kept together in the right concentrations and relative positions to enable life, or at least without some kind of containment or matrix (some forms of absorbent clays may have been involved early on – again, tentative ideas).

    Because of the evidence problems mentioned above it is hard to establish if the first cells originated from Earth or landed from space. I suppose if chemically very similar life was found extra-terrestially that would suggest some kind of inter-planetary links (though I suppose life may have started here and gone there would be as likely as vice versa?). But my money would be that life here started here – Earth has all the chemical ingredients, not least liquid water, sunlight and so on – and it just seems less complex than inter spatial transits. But rocks are exchanged between planets by meteorite collisions (eg Mars to Earth) and some bacteria can survive space, maybe as spores – so it cannot be ruled out.

    • In reply to #6 by steve_hopker:

      An obvious and probably insuperable problem in fully working out the origins of life is that it is very unlikely we will ever find much evidence of what happened ie fossils of the very earliest life. I think some of the earliest remains we do know – maybe 3.5 billion years old – are stromatolite cya…

      Very good, although it should be noted that photosynthesis was a fairly late development.

      Chemotrophs were around long before that developed and the environment was a hydrothermal vent as the early organisms required the higher temperatures to make the necessary chemical reactions take place. Whilst the deep sea vents are one such environment where this could have occurred there are also ones on land that would not have been dissimilar from those found in the African Rift valley today. The Chemical content of these thermal springs is responsible for the unusual colour of the water and sustains the bacterial colonies that thrive in the conditions.

  7. Phytoplankton and all plants survive just on water-soluble nutrients plus sunlight. Those nutrients may be dissolved minerals, or decomposed living matter. However photosynthesis, with CO2 absorption came rather late in the history of life on earth.

    “nutrients from the sun”.

    There is light from the sun. That is usually termed energy. Nutrients refers to things like nitrates, potassium salts, phosphorus salts, boron, magnesium.. which originally came from the earth.

  8. @ Jigger – Upon the creation of the first living cells (or even if those cells landed here from elsewhere in the cosmos) those cells had to ingest or absorb some kind of life supporting sustenance. If the cells didn’t start eating each other right from the start (predator and prey system),

    I think this video will give you a clear explanation of how abiogenesis can happen and how protocells can form.

    The Origin of Life – Abiogenesis – Dr. Jack Szostak – http://www.youtube.com/watch?v=U6QYDdgP9eg

  9. Could a living cell thrive on just oxygen and hydrogen, along with nutrients from the sun?

    No! Earth organisms need carbon, nitrogen, phosphorus and trace element-minerals. Some can however get energy from solar radiation or chemical sources such as sulphur or iron.

    • In reply to #13 by Trisapient:

      Eduardo, I had a quick scope at the overview, can you point to some encouraging reviews, or explain why your theory isn’t more widely known? Twenty quid is a bit much for me to outlay without a bit more substance. Your resume did give me some encouragement though.

      • In reply to #15 by Ignorant Amos:
        I just published it this morning and it struck me as funny that this very question would be posted It was Like just begging me to answer with my book.did you read the introduction I have been working on this theory for almost ten years and is a complete departure from everything else proposed until this point and because I was not wed to any one Idea I went where the evidence led.

        In reply to #13 by Trisapient:

        Eduardo, I had a quick scope at the overview, can you point to some encouraging reviews, or explain why your theory isn’t more widely known? Twenty quid is a bit much for me to outlay without a bit more substance. Your resume did give me some encouragement though.

  10. Hi and OK, let’s go for it, although it is nothing like a specialist subject for me.

    First thing to realise is that if a transformation happened, say on Earth (although I cleave more to the off-Earth suggestion), and assuming that it required special characteristics, you don’t need a world, a field or even so much as a thimble where those special cisrumstances come together. You have the whole world as your lab, and it is a mess of moving plates, volcanic activity that is putting iron here, sulphur there, potassium and iodine in other places. Inded, the early Earth is an extraordinarily complex and abundant chemical soup, a smorgasbord. Truly complex macro molecules can form, and even mere chemistry (plus crystallisation) can lead to a situation where a molecule absorbs calcium, say, for its surrounding water, and extends towards the sunlight.

    Enter the first double-helix molecular form, capable of zipping apart down the middle and drawing chemical component molecules from its (e.g. water) environment to fatten back the two zipped-apart halves. You have basic self-replication. Not a cell yet, not alive yet, just a chemical contagion that, so long as it has the necessary materials to hand, will continue replicating without stop.

    The first cell was essentially when the above event first happened in a bag. Any kind of a bag, an oily film, an air bubble. The newly replicated molecules are contained inside something… well, the rest is DEAD complicated. But at no time is there a “was created” or “life entered”. it’s simply a laddering up of emergent phenomena.

    (oh, and oxygen was expelled as a waste product by the first cyanobacteria. it ended up dominating atmospheric chemistry and, being poisonous to the cyanobacteria, wiped them all out.)

    • In reply to #18 by 4as4is4:

      Hi and OK, let’s go for it, although it is nothing like a specialist subject for me.

      (oh, and oxygen was expelled as a waste product by the first cyanobacteria. it ended up dominating atmospheric chemistry and, being poisonous to the cyanobacteria, wiped them all out.)

      Oxygen wiped out many organisms, but there are still stromatolites and cyanobacteria in some places today.

      The stromatolites in Hamelin Pool were discovered by surveyors working for an oil exploration company in 1956 and were the first living examples of structures built by cyanobacteria.[4] The cyanobacteria living in Hamelin Pool are direct descendants of the oldest form of photosynthetic life on earth.[5] The stromatolites are similar to 3,500 million year old stromatolite fossils found in many places around the world. Stromatolites are an example of the earliest record of life on earth. They are found around the shores, mostly in the neighbourhood of 26°23′S 114°09′ECoordinates: 26°23′S 114°09′E

      Hamelin Pool is hypersaline (it has approximately double the salinity of normal seawater), providing an ideal environment for the Stromatolites to grow, and inhibiting other marine life which would normally feed on the bacteria. The cyanobacteria live in communities on the sea bed at densities of 3000 million individuals per square metre. They are the simplest life forms to use photosynthesis to provide food and oxygen. They provided the early Earth with most of its oxygen atmosphere billions of years before plants appeared.

      Not only do they still exist independently in the salt-water pools, but via a symbiotic relationship some became incorporated in plant cells as the chloroplasts which now carry out photosynthesis in the plant cells throughout the world!

      http://www.ncbi.nlm.nih.gov/pubmed/12620099 -

      Genomics and chloroplast evolution: what did cyanobacteria do for plants?

      The complete genome sequences of cyanobacteria and of the higher plant Arabidopsis thaliana leave no doubt that the plant chloroplast originated, through endosymbiosis, from a cyanobacterium. But the genomic legacy of cyanobacterial ancestry extends far beyond the chloroplast itself, and persists in organisms that have lost chloroplasts completely.

  11. before there were cells, there was accumulation of organic molecules. i suggest you google the “heterotroph hypothesis” and read the last ten or so “tales” of Richard’s “The Ancestor’s Tale”. to get to the bottom of what seems to be a puzzle for you.

    You seem to want “a living cell” and fail to realize that there are stages before that living cell that matter.

    If you add carbon and make your list a four component list, you have described (for the most part) CO2 + H20 + sun = sugar and O2.

    That is photosynthesis. I am wondering why you left carbon off of your list of requirements considering that life is CARBON BASED?

    There needs to be a carbon source.

  12. The planet is around 4.5 to 4.6 billion years old. The first .4 billion year it was cooling off. Then rock solidified and water precipated and there was land and oceans. (And it was good, I guess). Then for the next .6 to .7 billion years ( that’s 600 million to 700 million years) prebiotic chemistry in the oceans, on he shores and inland took place. All the while he sun was putting 1.99 cal/square cm /min ( think) onto the earth. There was plenty of energy to pump into all the water chemistry going on. At the end of this 700 million years the first cells formed. Some of this is covered in Richard’s “The Blind Watchmaker”. The time was then 3.5 billion years ago. Life stayed single celled until about 6 to 7 hundred million years ago. The Cambian explosion is generally set at 540 million years ago and theats when the various multicelled lfe forms bloomed and started evolution on a grand scale. A lot of books go through this … and its all pretty much chemistry, then replicators ( either Ribo or Deoxyribo Nucleas acids ) that both copy themselves into the next generation and direct the making of the proteins, enzymes, and structures of the current and coming generations. Which is in the first chapter or two of The Selfish Gene. Also, of course, by Richard.

  13. There must have been something before cells, that is in between pure chemistry and biology. A state of organised matter that found a way to replicate itself (DNA), but still chaotic enough not to be called a cell. Maybe something without a membrane only held together by intermolecular forces or gravity or by lack of motion in its environment. But the beginning of life is not the cell. This is the befinning of complex life capable of adaptation and specialization!
    Endolithe, bacteria, archea and lichen live in rocks and exist perfectly without sunlight. They gain energy by reacting on the chemical base with their environment. There are a lot possibilities to gain nutrients from the ground without “roots”. But it is allready complex life so I think it’s not what you’re searching for. You want the real beginning.
    Maybe we should start trying to understand that the increase of complexety since the big bang is a universal principle and that maybe the contamination of matter with the structures we call life is just a logical step. Even the idea that life was braught from somewhere else to earth means that the ingredients of life, the necessary chemical elements came from there just like the water that is said to be necessary for the formation of life (Something I’m not so sure of. We tend to think only in ways that appear us to be logic and rational)
    But in fact everything – even the planet itself – was formed by stuff left over after our sun ignited and cleared the area around it. Later a lot of matter came in form of comets to the earth. The first state was much too hot for the formation of life. So it must have formed here based on ingredients available everywhere in the cosmos. That relativates our position in the cosmos a little but I guess that’s o. k.. …

  14. There must have been something before cells, that is in between pure chemistry and biology. A state of organised matter that found a way to replicate itself (DNA), but still chaotic enough not to be called a cell. Maybe something without a membrane only held together by intermolecular forces or gravity or by lack of motion in its environment. But the beginning of life is not the cell. This is the befinning of complex life capable of adaptation and specialization!
    Endolithe, bacteria, archea and lichen live in rocks and exist perfectly without sunlight. They gain energy by reacting on the chemical base with their environment. There are a lot possibilities to gain nutrients from the ground without “roots”. But it is allready complex life so I think it’s not what you’re searching for. You want the real beginning.
    Maybe we should start trying to understand that the increase of complexety since the big bang is a universal principle and that maybe the contamination of matter with the structures we call life is just a logical step. Even the idea that life was braught from somewhere else to earth means that the ingredients of life, the necessary chemical elements came from there just like the water that is said to be necessary for the formation of life (Something I’m not so sure of. We tend to think only in ways that appear us to be logic and rational)
    But in fact everything – even the planet itself – was formed by stuff left over after our sun ignited and cleared the area around it. Later a lot of matter came in form of comets to the earth. The first state was much too hot for the formation of life. So it must have formed here based on ingredients available everywhere in the cosmos. That relativates our position in the cosmos a little but I guess that’s o. k.. …

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