Reproduction? Help me understand!

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Discussion by: ElBeto

How is it that the first living organism had offspring? Wouldn't one expect, under undirected circumstances, that the first living organism that came into being accidently would eventually just die without having the foresight to reproduce? 

29 COMMENTS

  1. That would be because the first organisms were single celled lifeforms that reproduced through mitosis/meiosis (depending on the type). The sexual reproduction used by higher order lifeforms is a comparative late comer, showing up roughly 1200 million years ago compared to the approximate origins of life at 3900 to 3500 million years ago.

  2. Hmmn. There is so much wrong with the question that I wonder if it’s come from the Creationist’s Handbook of Devastating Arguments.

    First, the ‘first living organism’ is very problematic. What do we mean by ‘living’, for one thing? There is a growing body of evidence that suggests that early forms of ‘life’ may have arisen from things that we regard as inorganic. On another thread I drew attention to the stromatolite beds off Western Australia – nothing so much as rock that breathes and produces oxygen – that may give us an inkling that such things are possible. ‘Living’ may mean no more than ‘able to copy itself’. Even today, many bacteria do not reproduce in anything resembling the ‘usual’ way – they use something nearer to ‘copy and paste’.

    Second, what do we mean by ‘organism’? Whatever it was, it was incredibly simple, much more simple than bacteria. It did one trick (probably the only thing it could do) – it reproduced, perhaps by splitting.

    Third, the event that led to the establishment of life on this planet may not have been the first – in fact one could almost say it probably wasn’t. It was just the first successful one. To use the language of your question, it might be that many ‘organisms’ that came into being ‘accidentally’ died without having ‘the foresight to reproduce’. In truth, nothing had foresight – things just happened or they didn’t.

    Since then, of course, things have got very much more complex (but that’s the nature of evolution, not what we’ve been talking about here, which is abiogenesis, or biopoiesis).

  3. That’s a really good question. Please don’t pass it on to the creationists:-)

    I hope that better minds will correct me if I am wrong, but perhaps this makes sense: The first organism or more accurately I suspect, the first millions of organisms did not reproduce. They died and that was the end of them. But eventually one came along that was able to split and split again. That would have been our first ancestor.

  4. The Origin of Life – Abiogenesis by Dr. Jack Szostak This video summarizes one of the best leading models. Yes there are others. Science may never know exactly how life DID start, but we will know many ways how life COULD start. http://www.youtube.com/watch?v=J1XWtezOTvY

    The earliest life was self replicating single protocells, which then evolved into more complex cells.

    wikipedia.org/wiki/Abiogenesis Current models

    @OP- How is it that the first living organism had offspring? Wouldn’t one expect, under undirected circumstances, that the first living organism that came into being accidently would eventually just die without having the foresight to reproduce?

    The organic chemicals were probably replicating before they were complex enough to be living. This replication was likely to be inaccurate, until a chance more stable form turned up in the millions of reactions which were happening.

    Single celled organisms exchanged genetic material by contact with Horizontal gene transfer long before sexual reproduction evolved.

    @link – Most thinking in genetics has focused upon vertical transfer, but there is a growing awareness that horizontal gene transfer is a highly significant phenomenon and amongst single-celled organisms perhaps the dominant form of genetic transfer.

  5. Pabmusic (Comment #2) has given you an excellent answer.

    If I may, a few additions.

    Life is usually defined along the following lines. Life is a condition of an individual entity with all or most of the following conditions:

    • Capacity for growth

    • Capacity for reproduction

    • Functional activity (e.g. ability to move, ability to contact entities of the same type, ability to take in and process other entities or structures [i.e. to feed or breath], and there may be others)

    • Continual change

    • Death

    As Pabmusic notes; you do not need something as complex as a single-celled organism to have something that looks like life. This includes pre-cellular forms that were produced (e.g. by Earth’s geology) rather than reproducing.

    That said, reproduction is not such a difficult trick. Chemical reactions are predictable. As the Briggs–Rauscher and Belousov–Zhabotinsky oscillating reactions show an open system – such as the Earth, constantly fed energy by the Sun – will spontaneously do work at the chemical level. On this basis, we know that the emergence of chemical reproduction is highly probable. It is only a few baby steps from chemical reproduction to a life that reproduces.

    Most of the above is covered by a series of theories-in-development called Self-Organisation. However, as this paper explores, self-organisation lacks quantitative measures and, therefore, is not considered proper science as it is often unable to make accurate predictions.

    If you want to drive your understanding of the origins of life back beyond cellular life-forms you need to study physical chemistry and biopoiesis. I’m not so confident that I would put money on it, but self-organisation chemistry theories emerging from chaos theory, which will lead to some current biopoiesis theories being winnowed out, seems a likely way forward.

    Pabmusic also notes one other very important point. If self-organisation in chemistry is true at any level (and observation says it is) then the emergence of reproducing chemistry, and therefore life, is highly probable providing there is sufficient diversity of chemistry and enough energy. Clearly, neither of these conditions poses a problem on Earth. It seems almost trivial to ask: When those conditions existed how many entities that could reproduce would the conditions create? It seems, statistically, highly likely that it would produce large quantities.

    But evolution teaches us something amazing: It only had to happen once.

    Peace.

    • In reply to #5 by Stephen of Wimbledon:

      Pabmusic (Comment #2) has given you an excellent answer.

      If I may, a few additions.

      Life is usually defined along the following lines. Life is a condition of an individual entity with all or most of the following conditions:

      Capacity for growth
      Capacity for reproduction
      Functional activity (e.g…

      It seems like your explanation would have to be true. As a layman, my only question is, have we been able to prove in the laboratory that such chemicals do reproduce?

  6. How is it that the first living organism had offspring? Wouldn’t one expect, under undirected circumstances, that the first living organism that came into being accidently would eventually just die without having the foresight to reproduce?

    The obvious thing to say that is that instinct or foresight was not in play. The ‘environment’ was the instigator and sustainer of sex. Wind , rain , sun , chemical properties etc. The whole rational of evolution and natural history would suggest that.

    I think the big question is how genetic exchange and the splitting or organisms into male and female got started at all. I suppose as another poster said , it only needed to happen once.

    • In reply to #6 by Pauly01:

      The obvious thing to say that is that instinct or foresight was not in play.

      The early developments following abiogenesis and millions of years of evolution, pre-dated the evolution of two sexes, with horizontal genetic exchange producing diversity for selection (as it still does in bacteria). LUCA estimated to have lived some 3.5 to 3.8 billion years ago was the first common ancestor to ALL present-day life on Earth. You rightly point out – Evolution does not have “foresight”. It is opportunist!

      The ‘environment’ was the instigator and sustainer of sex. Wind , rain , sun , chemical properties etc. The whole rational of evolution and natural history would suggest that.

      Origin of sexual reproduction

      In the eukaryotic fossil record, sexual reproduction first appeared by 1200 million years ago in the Proterozoic Eon.[49] All sexually reproducing eukaryotic organisms derive from a common ancestor which was a single celled species.[1][41][50][51] Many protists reproduce sexually, as do the multicellular plants, animals, and fungi. There are a few species which have secondarily lost this feature, such as Bdelloidea and some parthenocarpic plants.

      I think the big question is how genetic exchange and the splitting or organisms into male and female got started at all. I suppose as another poster said , it only needed to happen once.

      See the link above.

  7. Trticky one. I’d say reproduction started before there was life.just a bunch of chemicals that tended to catylize the production of more of vtheir kind Where you would draw the .line & say this side is LIFE is pretty arbitary.- I’d go f0or the 1st creation of droplets with a boundary myself

  8. Oh, living things do not have this type of “foresight” you are implying. The first trillion living things may have died without reproducing, but the one that evolved that could split in two when it got to a certain size…… then you have descendants! And if the descendants are slightly different…. YES!!!!

  9. A living organism is one that responds to the environment, reproduces itself and inherits its characteristics. Imagine a unicelular being that clones itself and becomes two new beings. That’s all that was needed! Asexual reproduction was the only reproduction available for a long time. Sexual reproduction is a recent invention, in evolutionary timescale.

  10. That is why reproduction is the ” sideshow ” of genetic replication. Replication ( and quite possible a form of translation/transcription via RNA ) was going on long before any organisms were around to reproduce.

  11. Confusion about this might be a consequence of the terminology and myths that distort the evolutionary perspective. Especially the concept of accidental as being something unusual or improbable.

    If you have enough similar occurrences over a long enough period of time it no longer becomes a question of accident. It’s a bit like road accidents – the rate of fatalities from road accidents is fairly predictable. And most of these accidents are attributable to particular organisms exhibiting a repeated pattern of behaviour involving other serious vehicle collisions and criminally reckless behaviour. So these deaths occur because it is politically and economically convenient to do so. And there are economic analysis techniques that can reverse engineer these implicit political calculations to precisely determine the average price of a human life. Most of these accidents would be preventable – so should they be regarded as accidents or deliberates, even though no one has specifically decided that they will happen? A specific road accident fatality might be relatively improbable for the individuals directly impacted, but that a known rate of individuals will be impacted is a certainty. (This is the basis for insurance underwriting.) As individual organisms we are deeply concerned about individual organisms and our foresight and offspring. But these are irrelevant from an evolutionary perspective, which depends more on that some organisms are affected – we don’t really care which. There is no one directing the situation, just as no one is setting the death rate and price of human lives – nevertheless these things emerge as a direct consequence.

    The real question might be at what point in the evolution of life does a bundle of chemical processes and increasingly complex molecular structures become an organism? And the answer might be that we don’t really care – it’s a language and definition thing that doesn’t really assist with comprehending explanations.

    Reproduction is a fundamental property of life. So an organism wouldn’t be living if it wasn’t already performing processes that facilitate life, like consuming energy and growing by reproducing.

    Organisms could not have eventually sprung into existence and then reproduced. Instead there would have been increasingly complex molecular things that were reproducing which eventually became sufficiently complex to be organisms – with multiple molecular processes concentrated within membranes. Membranes being disrupted by environmental effects and spontaneously reforming (a basic property of these kinds of molecular structures) being the original cause of reproduction. No foresight or offspring involved. Just packets of molecules being knocked around in a complex environment. Ideal circumstances for chaotic structures to emerge with increasingly complex molecular mechanisms. Eventually organisms that developed the capability of disrupting themselves to facilitate reproduction would come to prominence. Simply because there would be more of them.

    Organisms might seem to have sprung into existence from nowhere but the required activities of life (molecular energy processing and reproduction) would have been occurring more haphazardly before organisms existed. Organisms are just a more efficient way by which living processes occur. Especially reproduction. A living organism exists because it is incessantly and rapidly reproducing an incredible variety of molecular structures internally, which wear out and decompose at a rate that is offset by their continual replacement. This is what living organisms consume energy and nutrients to facilitate and it occurs independently of the entire organism reproducing itself. The higher level of reproduction is really a reproduction of the capacity for reproduction. So even the word reproduction can be misleading. It means more than it seems. Organisms being so much more efficient at all forms of reproduction means that they crowd out previous alternatives.

    Once organisms became established then most pre-organism life processes would be irrelevant. In the presence of rapidly evolving and diversifying living organisms any conditions favourable to life (energy, nutrients, and stable environment) would then be dominated by organisms leaving little opportunity for more haphazard processes that preceded those living organisms. The establishment of complex living organisms might possibly occur frequently over deep time, but would effectively cease once organisms existed for the first time. One of the confusing aspects of probability is that you don’t get all those other times living organisms frequently emerged because they didn’t happen. Any 1 such event excludes all other subsequent such events. Just like you don’t get any 1 individual experiencing multiple car accidents where they are the fatality. Technically you can expect to be killed once if you drive a million km. But the maths doesn’t add up because you can be confident that you won’t be killed twice if you drive 2 million km.

  12. yes the first would but because the first happened it started a repeat beginning many many times until a slight difference occurred with out foresight without knowledge without anything just repeat

  13. OP assumes life arose first, then came reproduction/replication. In fact, it was self-replication which came first, in the form of organic molecules that though non-living were subject to a natural selection process that gave rise to more complex forms and eventually something we’d call alive. Life came from stuff that was already copying itself.

  14. Many things that are not what we would call alive can reproduce (make copies of themselves) or more precisely have structures that tend towards copying. If you take a crystal in a supersaturated solution of say copper sulphate you can trigger sudden crystal formation, if bits of the growing crystals break off they can in turn trigger more crystals to grow around them following a similar pattern. Some clays do something similar in the right conditions as do snowflakes and many other things. In experiments with RNA they have got some self replication going but not enough to become self sustaining (yet).

    So it is likely the the first replicators where that replicators not living in any sense we would call living. However self replication is simply an essential first step.

    It reminds me of the chicken and egg question, which is one of the silliest questions to ask now-days. If you are creationist you answer the chicken came first it was created. Or if you are better educated (or without religious bias getting in the way of the facts) you answer ‘the egg’ as it predates birds by hundreds of millions of years let alone chickens specifically. I digress.

    So the short answer is don’t know yet but likely it wasn’t what you would call living at the point it gained the ability to self replicate and the are plenty of non-living things that self replicate to a point to suggest possible ways without inserting an infinite regress to make it even more complicated.

  15. That would be because the first organisms were single celled lifeforms that reproduced through mitosis/meiosis (depending on the type).

    The earliest life was self replicating single protocells, which then evolved into more complex cells.

    Hey wait a second…Isn’t this taught in 7th or 8th grade science class maybe even earlier? Everyone has used a microscope, right? This should be common knowledge, shouldn’t it? If someone scientifically illiterate as me knows this, how are people graduating from high school?

    Maybe you can help out with this ElBeto – unless you’re in school or one of the many people who stop in to ask questions (considered to be “challenging”) and then leave.

  16. This is not a question. This is a transparent and rather obtuse objection to the idea that life arose naturally.

    To the religious person known as ElBeto; no, one would not expect that under “undirected circumstances”, because replication preceded the first living organisms. Replicators, simple organic compounds that could make copies of themselves, came first.

    RDnet should be more selective as to what it posts as discussion material.

    • In reply to #20 by blitz442:

      RDnet should be more selective as to what it posts as discussion material.

      I thought so too, initially, because the OP is so crappy.

      But the answers, well, they’re mainly pretty good. So, is anyone making any progress on building an FAQ section that can include simple (or dumb?) questions like this one, and a collection of the most informative answers and links, maybe weeded of duplication?

      Then future dumb questioning posters can be refered to the FAQ, and this section used for more advanced topics. Mods? Anyone?

      • In reply to #21 by OHooligan:

        In reply to #20 by blitz442:

        RDnet should be more selective as to what it posts as discussion material.

        I read this post today – admittedly a few days after everyone else. I don’t think RDnet should censor the posts for a number of reasons. This is a discussion forum and, as such, should leave space for differing views to be aired – even if some views are apparently stupid.

        Secondly, I’m not sure there is really such a thing as a stupid question. There are questions that people may think are stupid, but that’s another matter. That may say more about the attitude of the hearer than the speaker. However, if a person is seeking an answer to a question then, no matter how many other people already know the answer, for that person, it’s not a stupid question.

        Having reviewed the post and comments, I appreciate those who have sought to provide information in response to the original question. For the others, I regret that the readiness to insult the questioner seems rather unnecessary and a little unkind, if I may say.

        On further reflection, it’s not a dumb question, because whatever organism it was that first reproduced – whenever that happened, it was still the first one to do so, and therefore the premise of the question is not so wrong after all.

        Let’s all play nicley, shall we?

  17. The first step along the way to life was in most theories of abiogenesis self replicating molecules. You might not call them living things, but they processed the minimum requirement for evolution by natural selection, that is inheritance. From there more recognizable living things evolved.

  18. One answer is the definition of life includes reproduction, even if just splitting like an amoeba. There would have been trillions of “false starts” that had other attributes of life but did not reproduce.

  19. With DNA sequencing we are very close to building arbitrary lifeforms totally from scratch. When that happens I think concern about exactly how life did arise will wane. We will see at least how it could have happened in principle and that will suffice. It will cease to be magic only God could have done.

    • In reply to #26 by Roedy:

      With DNA sequencing we are very close to building arbitrary lifeforms totally from scratch. When that happens I think concern about exactly how life did arise will wane. We will see at least how it could have happened in principle and that will suffice. It will cease to be magic only God could hav…

      No we aren’t.

  20. In the larger Internet, when people ask questions that could easily answered with a google search, they get a shower of virtual vegetables.
    RDF is much more tolerant. I am rather puzzled why the moderator has preferred your disingenuous questions to serious ones.

  21. For an organism to come into existence it is only necessary for it to have a DNA sequence that codes for itself – the various proteins, amino acids, enzymes, etc. that it requires for existence and house all of this in a shell (cell), but for it to have offspring (divide), that DNA sequence must also not only code for itself but must also contain the coding for DNA (or RNA) replicase. Without this, the DNA is unable to copy itself and hence the organism dead-ends. Life may spontaneously generate all the time as small DNA chains come together in a successful sequence but without the replicase it simply lives its single life and dies out.

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