In 1953, a young doctoral student named Stanley Miller conducted an experiment that revolutionized the way we perceive the beginning of life and actually created a completely new field of science called Abiogenesis.
In 1953, a young doctoral student named Stanley Miller conducted an experiment that revolutionized the way we perceive the beginning of life and actually created a completely new field of science called Abiogenesis.
Under the patronage of Harold Urey, Miller performed the first experiment that tried to find out how life was created. In their laboratory they tried to simulate the conditions they thought prevailed on the ancient Earth. They filled a test tube with water (H2O), methane (CH4), ammonia (NH3) and hydrogen (H2) and passed electric currents through them. When Miller analyzed the substances created in the test tube, he found five different amino acids - the building blocks of proteins and an essential component of life (the basic structure of an amino acid is: H2NCHRCOOH. The meaning of R is the free group that changes between different amino acids). This was the first time in which they showed that under relatively simple conditions it is possible to obtain organic substances from inorganic substances.
In the following years Miller repeated the experiment but with some changes. He added steam to simulate a volcanic eruption and in other experiments he also changed the materials in the test tubes and added hydrogen sulfide and carbon dioxide to the methane and ammonia.
For some reason Miller did not finish tracking all the experiments and did not publish their results. On the other hand, he did collect all the results in well-cataloged tools and kept them. And like a good scientist who doesn't throw anything away, he continued to keep them.
In 1999, Miller suffered a stroke and passed his scientific legacy to his former student, Jeffrey Bada. Miller died in 2007 of heart failure. Bade encouraged his students to examine the inheritance he received from Miller, and so in 2008 Adam Johnson showed that Miller's original test tubes had a wider variety of amino acids than was found in 1953. On March 21, 2011, the journal PNAS published the results of another follow-up study to one of Miller's experiments. Eric Parker examined the results of an experiment conducted by Miller in 1958. It was the first experiment that included hydrogen sulfide, the substance that causes rotten eggs to stink and is a prominent component in the gas emissions of volcanoes. Using modern methods for analyzing materials, roughly a billion times more sensitive than Miller's, Parker's team found 23 amino acids, seven of which contained sulfur. This is new or old knowledge for science, depending on how you look at it. Other scientists had already achieved this result, not knowing that Miller had arrived at it before them. Miller even got ahead of himself, only in 1972 he published an article about a study in which he received sulfur-containing amino acids. Some of the amino acids appeared for the first time, among them methionine, which is very important for building many proteins in animals, plants and fungi. The new arrangement of amino acids is very similar to that found in meteorites, a possible hint that sulfur may have helped assemble the materials essential for life outside of, or on, Earth.
How do you know that the source of the amino acids is not contamination, bacterial for example, of the samples? The amino acids in Miller's test tubes arrived in equal amounts of pairs of forms - a mirror image of each other (chirality). This result is obtained almost only in the laboratory, in nature we almost always see only one form.
The main problem with Miller's experiment is that he was probably wrong about the composition of the ancient soup as it really was. Analysis of ancient rocks has led scientists to conclude that the Earth has never contained so many hydrogen-rich gases as methane (CH4), hydrogen sulfide (H2S) or pure hydrogen (H2). If Miller's experiment is repeated under more realistic conditions - rich in carbon dioxide (CO2) and nitrogen (N2), with tiny amounts of other gases, it is difficult to find amino acids.
The solution offered by Parker is that it is enough that there were several individual places with the conditions suitable for the initial creation of life. Active volcanoes, for example, emit large amounts of sulfur compounds as well as methane and ammonia. If there was a lightning storm, amino acids may have been formed and fell into puddles with the rain. But even this solution is not perfect since it will be difficult to obtain high enough concentrations of the necessary substances to resemble those that prevailed in Miller's experiment.
Even if we assume that amino acids can really be created spontaneously in such a way, there is still a big gap between amino acids and something that can be called "living". The really big challenge is to create nucleic acids that build molecules like DNA and RNA. The origin of life depends on the presence of those molecules capable of replicating themselves. The problem is that nucleic acids do not tend to connect to each other spontaneously and it is difficult to assume that a lightning strike was a sufficient stimulus. The molecules had to be concentrated in one place with enough energy and catalysts for the process to happen.
The research dealing with the creation of life contains two opposite approaches - the first from the bottom up: we must first create the essential components in a logical way and only then continue to examine how we got from them to the first living cell. The second: from top to bottom: choose a point on the continuum of the formation of life and see that it can occur spontaneously. Over time we can connect these dots to create the complete story. With this approach, for example, scientists have already succeeded in producing ribozyme, which is an enzyme built from RNA nucleic acids, which catalyzes its own replication.
So where did life begin? If we assume that the beginning of life did occur on Earth, deep sea hydrothermal vents are a more acceptable hypothesis. Deep at the bottom of the ocean, these rocky structures emit boiling steam and hydrogen-rich gases. The rocky structure is built as a labyrinth containing many places where a sufficiently high concentration of the materials necessary for the beginning of life can be created, along with minerals that can be used as catalysts.
In his experiments, Miller achieved a breakthrough in the way we think about the creation of life, even if his original hypothesis is proven wrong, and therefore his experiment is considered basic knowledge for every biologist. An equally worthy achievement (in my opinion) of Miller lies in the fact that, after more than fifty years since he packaged his experiment, a student could take the carefully cataloged, documented and preserved test tubes, and continue where Miller left off. Can the lab mice among you say the same about the materials they leave behind?
http://www.youtube.com/watch?v=5VxoWINkzqo
An episode of the BBC series The Cell explaining the research surrounding the beginning of life. The reference to Miller's experiment starts at minute 19 (English, no translation).
Reference: Parker, Cleaves, Dworkin, Glavin, Callahan, Aubrey, Lazcano & Bada. 2011. Primordial synthesis of amines and amino acids in a 1958 Miller H2S-rich spark discharge experiment. PNAS http://dx.doi.org/10.1073/pnas.1019191108
20 תגובות
The ability to create real life is not reserved for humans.
We will never be able to program a computer that will love a thought, that will feel, that will experience, that will regret, that will be happy, that will make decisions according to its feelings.
It is beyond the human ability to put life into an inanimate object.
Turn dead atoms to say alive is in awe.
To 17
It's really strong what you say.. Technological evolution is a good analogy for evolution in nature. I wonder if those religious people who believe that the process of evolution is intentional, also believe that the Wright brothers designed the Boeing 747 from the beginning or that the inventor of the vacuum tube is a super-planner, who also designed the 'iPad' or the 'BLUE GENE' from the beginning..
to sparrow (17)
And this is exactly the difference between religion and science, with the former someone came up with a theory (which was probably logical for his time) and it stopped there. In science, on the other hand, you make a logical assumption and then test it with experiments. Most explanations turn out to be wrong, a minority pass the tests and are therefore perceived to represent the knowledge of reality as of this moment, and in any case knowing and ready to replace the same opinion if you find a better one. So there are people who still believe that the "truck" has been here since time immemorial, and there are those who have already rejected this explanation and discovered that the existence of wheels for their special properties, and the existence of an engine for its special properties, and the existence of other components that link between them, all of these allow movement and therefore can be raised new beliefs about what happened in the past and to think of ways to test these explanations experimentally. The tragedy of religion is getting stuck in believing in a false belief when those who hold it can never discover it because the prohibition against examining it is built into that attitude.
That's how it makes sense. Based on the information available to the thinking person.
If I'm some kind of person from a culture where the wheel hasn't even been invented yet and I come across a truck, how will I even understand what I'm seeing? How will I come to the conclusion that this thing "traveled" here? I will probably think logically and come to the conclusion that it has been here forever.
13,
Of course, if you walk in the desert and see one watch, you will conclude that it was created by a creator. However, if you reach a planet with billions of clocks that mate with each other and create new clocks that are slightly different from their parents, then yes, you will understand that it is likely that these clocks were created by natural processes.
The question is over,
It is very likely that the creation of life did not occur today due to several reasons. First of all the conditions are different, for example there are high oxygen levels in the air (about 20%). And the second and more important reason is that there is no niche on Earth capable of containing life that is not populated by creatures that utilize every possible food material. So even if a replicating molecule is formed it will be destroyed immediately.
The only place such a process would probably take place would be a test tube in some biological laboratory.
To 13:
Wait wait wait, are you sure a clock can't be created incrementally? I mean, it's clear that the clocks we know were created in a factory or by a watchmaker (or by a scientist), but is there something in principle that prevents a clock from being created gradually? Do you know what it is?
Please explain in what sense "their level of complexity is similar" (do you mean the number of their parts? The chemical properties of the materials they are made of? By the way, do you think the latter two are equally relevant to the topic of complexity in this context? And no less important, can you quantify the degree of complexity in both cases? )
The question is not whether the replicator is complex but whether it is complex to such an extent that it is necessarily impossible for it to be created by natural processes. Do you think this is also easy to prove? In my opinion, you are a quack who bases arguments on logical fallacies and I have several passages of text that demonstrate this, you, on the other hand, have not presented any argument that supports your opinion.
Well? And what will your next bunny be? A robot made of organic materials? After all, that direction has also been tested and found to be unfit for the food of a thinking person.
You can't compare watches to biological creatures! If watches gave birth to offspring and passed on their traits to them, and their chances of survival depended on their accuracy and external beauty then you could make this comparison.
But since this is not the case, this comparison is simply ridiculous.
Camila, we don't know how a clock can be created gradually, just as we don't know how a replica can be created gradually. And since that is the case, and because the level of their assembly is similar, you must claim that a clock can be created by itself.
In my opinion it is very easy to prove that a complex system is required for replication.
Is it possible that even today life is still being created on Earth as a result of various chemical reactions, but it is "swallowed" in the bustle of life that already exists here and therefore no one is aware of it?
Lotem,
Although the Miller experiment is one of the classic experiments and one of the most important milestones in biology, it seems today that its results do not reflect the beginning of life.
Today most researchers think that life began with RNA molecules that replicated, at a later stage they were probably wrapped in fatty envelopes that protected them and only then did amino acids start to play a role when peptides and proteins were created. The origin of the amino acids could have been spontaneous as shown by Miller's experiment or from meteorites (as found) or they could have been produced by the RNA enzymes in a similar way to what the ribosome does (actually its 23S subunit).
Of course, none of this should detract from the value and originality of the Miller experiment.
To 8:
In answer to your question - but there is such a scenario... and it is part of the evolution process. But let's say if there wasn't, then my answer to you is - no. Definately not.
On the other hand, you and your ilk would come to the conclusion, which is incorrect in retrospect, that stars, geological formations (such as mountains, rivers and stalactite caves for example) and also the animals that exist today as well as a significant number of other gradual processes that create patterns and compositions that did not exist before, were all created at once on by an unknown creator (much more complex than his creation and which has existed since time immemorial without any plausible explanation), and all this based on the same lame argument that if we haven't had one type of scenario for a long time then there must be another, much more dubious, scenario that is necessarily true. And then, after you had come to this conclusion, and it would become clear to those of you who bothered to open Wikipedia or read scientific articles or, best of all, check for yourself through an experiment, Mercifully Lezlan, that in fact such "impossible" scenarios were discovered that are completely based on natural processes that explain these phenomena really well, you would We are forced to come up with explanations why an unknown creator is not actually needed for the processes for which natural causes have been found. What is really amazing in the whole story is that those who hold this idiotic way of thinking still continue to passionately claim that such a stupid creation is bound by reality for the phenomena for which we have not yet found an explanation as of this moment, according to their limited knowledge. And so time and time again, those with this crooked way of thinking are forced to retreat further and further, to come up with quibbles and excuses and reservations like the last of the lawyers of the crime families, who have no interest in understanding anything or reaching the truth but only rape reality with the help of an all-encompassing axiomatic belief, which must never be replaced even when it is revealed in all its waste and folly, even when it goes against simple logic and basic human morality. As a scientist, if I were to reach the unfortunate state of not having any more possible scenarios to test (research hypotheses) it would be because my mind had degenerated and died. To my great joy, I look around and see how science flourishes and confuses despite all the difficulties.
And to be constructive, if you can propose a way to scientifically test the scenario you propose regarding the creation of a cat out of nothing, you are welcome to share it with us and put it to the test (at least of common sense at this point). In any case, your proposal for a scenario certainly cannot be a conclusion from what you have written so far because it is based, as mentioned, on your logical fallacy, not knowing how to explain something in one way inevitably leads to the correctness of a certain explanation in another arbitrary way. This thought fallacy would also be valid if that arbitrary "explanation" was testable and was free of other shocking logical inconsistencies.
RNA polymerase:
First of all - you should know that it is impossible to experimentally disprove the claim that a simple duplicate can be created in a natural process, so your claim in this regard is a misunderstanding or a lie.
At most it is possible to disprove the claim that a specific and defined process does not create a first replicator, but such a disproving does not say anything about other processes.
Besides - almost everything we know how to do today, people 200 years ago did not know how to do and they could say just like you that in light of billions of years of experience where they did not know how to do it, it should be concluded that it is impossible.
So this argument is also a logical fallacy.
Besides - you should read here about speculations regarding the formation of the first living cell:
http://sciam.co.il/archives/1833
And after all this - if you demand from yourself what you demand from sane people then please tell us how the first God was created.
For 5 and 7:
Crystals do not transfer genetic code, so they cannot be the first to replicate.
For your information, the argument for a simple replicator that can be created through a natural process is disproven in every possible experiment. So according to science we have to abandon the hypothesis of a simple and anonymous replicator. It is already better for us to champion panspermia. The very fact that, despite all the attempts, there is no answer to this, should prevent sleep from the abiogenesis advocates.
I have a question for you - if you had no scenario for the gradual formation of a cat, would you conclude that it was formed all at once?
To 4:
You are allowed to say that you know nothing and even in that you are wrong.
The fact that we do not know as of this moment what the minimum combination is that can enable the appearance of life, does not say anything about the feasibility or impossibility of such a combination. The fact of not knowing as of this moment also certainly does not point to an imaginary scenario, fundamentally far-fetched and lacking in empirical foundation, both at the level of observation and at the level of experiment, as the reasonable explanation for the appearance of life, let alone being the only possible explanation. The knowledge that we do have, and which you make sure to ignore, actually supports the possibility of the existence of simpler replicas than those known to us today, and in general it supports that the whole variety of phenomena that exist around us are natural and not supernatural.
There are people whose logic works in the following way: "I don't know anything, therefore there must be a supernatural force that is responsible for the same thing." Apart from the gross logical error that exists at the base of this axiomatic way of thinking, such a thought eradicates from its content everything interesting that we experience in this world. This is not an error, it can be an axiom that presupposes a logical error and there is a reason why such axioms are not "common" in science. So you may feel like you don't know anything and you're probably just as well in a dull, degenerate world where you have standard filler that no hole is too big to fill with. I, on the other hand, already know for example where your response is heading and that this path is a dead-end path that previously contributed nothing to the discussion here because everything was summed up in your idiotic attempt to convince that if we don't know anything then all kinds of far-fetched and logically incorrect conclusions are warranted, such as the claim that statistically natural creation is impossible (And this is of course without the slightest recognition of the laws and the statistical model that is relevant in this case) or that there must be a supernatural creator (in his washed-up names, or God in his own right after scratching the surface a bit). You have tried to sell this before and failed miserably, you are welcome to move on to another place where they will be happy to cooperate with crooked thought forms of this style. We are here, at this moment, we will continue to not know the bottom line answer to this specific question, we will continue to read about new discoveries that support again and again the direction that the solution is probably miraculous in its simplicity and is completely natural and we will stay away like fire from fillers that do not explain anything but only fix the wakefulness.
https://www.hayadan.org.il/images/content3/2011/04/miller-yuri-experiment.jpg
For 4.. This is not necessarily true.. Crystals are simpler replicas.. Put a crystal in a solvent of the same substance and you will get more crystals...
What you might have to think about.. is some simple replicator.. not surviving the changes in climate and atmosphere between then and now..
Lotem, so we actually know nothing.
All known researchers agree on one thing - first of all, a replicating system is required. The problem is that the simplest replicating system requires complex proteins from the polymerase family. Otherwise, it's like connecting a chain of Lego blocks by natural processes. Some energetic action is needed to carry out the complex process.
The same goes for the autocatalytic ribozyme you gave as a model - it is both too complex and replicates only a small number of sequence-dependent bases.
Of course, this is only the first step. After that, a translation system is also needed. which itself is no less complex.
Thanks!
In the end it will turn out that the ancient soup was actually cholent. Only such soup can explain why the fish rushed out of the sea, or why the dinosaurs became extinct, and why it was urgent for the reptiles to start flying.
The secret lies in the ingredients of the cholent and its unique chemical products.
Interesting article, and a fascinating video, thank you!