Can we create life from scratch?

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Injecting desired genetic code into bacteria marks a significant advancement, yet it does not equate to creating life from scratch. Theoretical discussions suggest that assembling the necessary chemicals to create a living cell is possible, but current scientific understanding of cell complexity limits practical attempts. The first fully artificial cell is unlikely to exhibit intelligence or self-awareness, as it would function similarly to existing unicellular organisms. While nature has historically relied on existing cells to create new life, the potential for synthesizing life from non-living components remains an intriguing area of exploration. Overall, the conversation highlights the complexities and uncertainties surrounding the origin of life and the conditions necessary for it to emerge.
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People have achieved injecting desired genetic code into bacteria. This is a big thing of course but it is far from creating life purely out of chemicals.
Assuming 'life' to be the ability to interact with the environment for benefit and to reproduce, is it possible, at least theoretically, to assemble the necessary 'life chemicals' and create a living cell?
And if it is possible, what would it speak about things like intelligence and self-awareness?
Just trying to know your opinions.
 
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I see no reason why it should be fundamentally impossible.
It is not possible at the moment, however. Cells are not well enough understood, and too complex to assemble them molecule by molecule with current chemistry.

And if it is possible, what would it speak about things like intelligence and self-awareness?
I don't think the first fully artificial cell will show those features more than a regular unicellular organism. It would disprove vitalism completely, of course.
 
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is it possible, at least theoretically, to assemble the necessary 'life chemicals' and create a living cell?
In principle... that would have to be a "yes". There is no reason to believe that one cannot start out with all-dead stuff and deliberately build some sort of living organism.

Scientifically the ability to scratch-build a living organism from non-living components says nothing at all about intelligence or self-awareness. [Could disprove a lot of ideas though.]
 
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how does a female's(in most species) womb create it ?
that's probably a great place to start.
 
Depending on how you define life, viruses have been generated from cell-free systems (Cello et al. 2002. Chemical Synthesis of Poliovirus cDNA: Generation of Infectious Virus in the Absence of Natural Template. Science 297: 1016. http://dx.doi.org/10.1126/science.1072266).
 
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krash661 said:
how does a female's(in most species) womb create it ?
It does not do this. It uses existing living cells to make more living cells. That is easy to reproduce in a lab.
 
In principle yes but in practice our knowledge in this field is highly limited so any organism created "from scratch" would likely be cobbled together from parts of other organisms. Synthesising an already in existence genome and planting it into an empty cell is one thing, designing and building an organism not modeled on nature is quite another
 
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how does a female's(in most species) womb create it ?
that's probably a great place to start.
Do most species have male and female?
Do all females have a womb?

Mammals make more mammals by assembling already living cells in a womb - so maybe not such a good place to start. But if the definition of life does not extend to the zygote, then you are on to something :)

But this sort of question is commonly asked by creationists and vitalists - "life must come from life", so knowing how a womb makes new life is unlikely to count. Leveraging the mechanisms seen in nature would also likely not count (we learned about them from life) ... making the proposition extremely difficult. Technically everything life we build from non-life comes from us and we are alive and we get bogged down in semantics.

Our bodies do need to be able to take dead stuff to make living stuff (all those cells in your body came from someplace) - all we really need is a totally artificial food, eat it (wait a bit) and you've made living stuff from stuff that was never alive.

The starting point for lab-created life would be at the really simple level - viruses and viroids perhaps.
 
 
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  • #10
It is amazing how some molecules are capable of self replication.
 
  • #11
The lecture in Borek's post is an example of something that is massively frustrating - here we have someone at the front of his field, so we want to listen to him, lecturing an inherently fascinating subject, so we want to hear about it, but he does it in the most boring way possible! If someone were to deliberately try to make the Origin of Life boring, they would be hard pressed to do better than to deliver in a monotone (peppered with upwards inflections at the end of some statements of fact) with erratic pauses and lots of ums and ers.

The lecture itself is great.

The number of times I've hunted and searched for some presentation to nail a topic, only to find the delivery is counter-productive. The really good delivery items are often too pop-sciencey to be much use.

It's also the number-1 complaint from students isn't it?

(To be fair - there are bits that are easier to listen to; particularly after the half-way mark when the lecturer warms to his subject. Public speaking is hard and we can't all be Richard Feynman.)
 
  • #12
s0ft said:
It is amazing how some molecules are capable of self replication.
Be that as it may ... has your question been answered? Has your topic been addressed?
Feedback is important to the sort of replies you get.
 
  • #13
From the presentation, I feel I can safely take the chemical origin of life now.
But to think life can exist in totally different forms compared to that we see here on Earth seems very radical to me. Sort of hard to imagine it. But I don't know, maybe there are still a lot of fundamental bits like mfb said,, that we don't know about life yet.
And thank you everybody, I didn't expect such a lot of replies to be honest, though I really hoped there'd be. But maybe the subject itself is a very interesting one and that is to be held for it.
 
  • #14
s0ft said:
People have achieved injecting desired genetic code into bacteria. This is a big thing of course but it is far from creating life purely out of chemicals.
Assuming 'life' to be the ability to interact with the environment for benefit and to reproduce, is it possible, at least theoretically, to assemble the necessary 'life chemicals' and create a living cell?
And if it is possible, what would it speak about things like intelligence and self-awareness?
Just trying to know your opinions.

Even nature has trouble doing this. EVERY living cell was created by another living cell. None are created "from scratch". Well except once 3.5 billion years ago. But that first cell had an easy life because there was no competition. Nature could not do this again because such a primitive cell could not compete with existing life.

One way to create life might be to emulate the way if happened on Earth 3.5 billion year ago. The first "life" was just a short strip on RNA that may not have even have had a cell membrane and it likely also folded and acted as it's own enzyme. Proteins and DNA came much later. You can build a lot with just RNA. The Earth was different then, no O2 in the air. You need to recreated the ancint environment and then toss just one carefully crafted RNA segment into that environment. That is how life was created and it may be the only way possible. We don't know.
 
  • #15
Even nature has trouble doing this. EVERY living cell was created by another living cell. None are created "from scratch". Well except once 3.5 billion years ago.
Probably many many times 3.5-4.5 billion years ago.
You need to recreated the ancint environment and then toss just one carefully crafted RNA segment into that environment.
... and wait for a long long time ;)
 
  • #16
...and wait for a long long time
It makes me think, given enough time, is it possible that anything that can happen, will happen?
And was it just luck that the right sequence of these molecules started getting together or would it be more accurate to say that over the interval of time presented, it was destined?
 
  • #17
The way evolution works it is enough that you have something that barely works - if it multiplies and compete for resources, it will get optimized over time. Doesn't mean everything will happen. Once you have something that works slightly better than barely, newcomers - which are still just barely working - won't be able to outcompete it. So you can probably start only once.
 
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  • #18
s0ft said:
It makes me think, given enough time, is it possible that anything that can happen, will happen?
And was it just luck that the right sequence of these molecules started getting together or would it be more accurate to say that over the interval of time presented, it was destined?

Destined is the wrong way to think about it. More like certain environmental conditions allow for a higher probability of self-replicating molecules forming so over long time periods (as long as the environment doesn't change) it is more likely to happen.
 
  • #19
s0ft said:
It makes me think, given enough time, is it possible that anything that can happen, will happen?
That would be the definition of "enough time" then wouldn't it?
You don't get to go backwards all that much though so once on a path, events have to continue along it.

And was it just luck that the right sequence of these molecules started getting together or would it be more accurate to say that over the interval of time presented, it was destined?

How many times would you have to roll a fair die before it is certain that you will roll at least one six?

The rest of these terms are vague: what is "luck"? How would you recognize it if you saw it? Destiny?

In AD&D you have to generate characters by rolling 3 dice and adding the total. But there are gamer tricks to get a higher value while keeping the actual number random ... eg - one rolls 4 dice, reroll the 1s and discard the lowest.
So, in this example, on the first roll I get 5,5,1,1 ... now the odds have changed - I cannot get less than an 12 for that attribute, because some dice rolled high that time. It could have been different? Was it fate? Was it an accidental sequence of events?

What is the "right" sequence of molecules? We happen to think that the RNA-DNA etc stuff is important because we are made of it ... but isn't that is just our own arrogance in thinking we are important? Why can't the "right" sequence be the one that leads to alcohol and all the rest is wrong? The only meaning to these events is what we assign to them.

Perhaps there are other sequences that lead to other kinds of self-replication that can develop the kind of complexity we normally associate with what we please ourselves to call "life"? Just 'cause we have it does not mean it's the only way. There is no way of knowing, yet, and detailed speculation is pointless. The point: let's not get up ourselves eh? The Universe still has a lot to teach us.

What is clear is that, in this "big" "old" Universe, there is enough room and time for many apparently unlikely things to happen. That's the thing about probability - the odds of an outcome change with the number of opportunities to roll the dice - and how the dice are rolled.
 
  • #20
So you mean to say that even if the given interval of time is long 'enough', we still cannot be sure that life starts?
If the universe still has a lot to teach us, that can only further justify my point that anything that can happen will, eventually happen. And although I don't and didn't ever mean to say that 'this kind of life' or we 'humans' are the purpose of it all, which I think you believe I have faith in, if you say life can be something entirely different than what we observe, that argument adds to the 'favourable cases' for the chances of origin of 'life', no?
Correct me if I got you wrong.
 
  • #21
this conversation turned out to be more interesting than what i had thought.
nice.
 
  • #22
Please excuse me - I'm not sure we are disagreeing exactly - I hoped to warn you off some unhelpful ways of talking.

s0ft said:
So you mean to say that even if the given interval of time is long 'enough', we still cannot be sure that life starts?
No - I am saying that the word "enough" here is meaningless without some statement of how much time is "enough".

If the universe still has a lot to teach us, that can only further justify my point that anything that can happen will, eventually happen.
It does not mean that anything at all can happen or even that all events that are possible are certain to occur sometime, somewhere.

Some events can exclude other events for instance.
But it does mean that we can expect events which we intuitively feel are unlikely to have occurred - our intuitions about what is likely or unlikely are not very helpful here.

And although I don't and didn't ever mean to say that 'this kind of life' or we 'humans' are the purpose of it all, which I think you believe I have faith in, if you say life can be something entirely different than what we observe, that argument adds to the 'favorable cases' for the chances of origin of 'life', no?
Correct me if I got you wrong.
The unhelpful language here was in referring to the sequence of events as the "right" sequence. It is not clear what this means but it is often used to assign some importance to a particular process above others. Don't use it to argue with Creationists for example.

The possibility that there could be other processes elsewhere does, indeed, add to the favorable cases for the origin of life - though we'd have to extend our definition of "life" to include those other processes.

Some people won't want to.
Can we come up with a definition or test for "life" that does not rely on something anthrocentric?
How would we recognize it if we saw it. It's tougher than it looks. Not everyone counts viruses for example.

I don't think life is terribly unlikely on the scale of the Universe ... but you have to remember what the Universe does to numbers with lots of zeros in them.

I remember someone telling me that their favorite authority, told them that the odds of a star having a planet with intelligent life was one to the number of hydrogen atoms within eight light years of the Sun. He thought that was such long odds it couldn't possibly happen.

Never mind that the number is totally bogus: you can work it out! (~10^150)
Then compare it with the number of stars in the observable Universe (~10^1021).

Those kinds of numbers allow for some pretty long (by intuitive measures) odds to be achievable.
But it does not mean that anything can happen. We can always find something with really really long odds on the scale of the Universe long. Then there are those things that get ruled out because physical laws turned out a certain way.

Maybe the laws are more like guidelines - but that's one maybe too many: there are rules about that sort of speculation in these forums... our current understanding is that not just anything can happen.

Anyway - that's about all the metaphysics I can handle tonight ;)
 
  • #23
Simon Bridge said:
Probably many many times 3.5-4.5 billion years ago... and wait for a long long time ;)

No. I disagree. Once live got started, the next time something very primitive got going, it got eaten very quickly. Those primitive RNA strands with no cell membranes would not stand a chance today even a virus needs a protein shell to survive today.

OK it might have happened twice, each time in a very different isolated environment but as soon as those environments came in contact the primitive stuff was over run. So if it did happen many times, the ones who where late to the party did not have it so well.

And no again. if the goal is to create "life" (any kind) from scratch, there is no need to wait, that first RNA you introduce to your artificial environment is "life". It is primitive but if it is self replicating and uses energy and nutrients it's life.

But if the question is can you build "modern multi cell life" in one step from scratch, I'd have to say no. It has never been done by nature. You have to go one step at a time or start with a living cell and modify it.
 
  • #24
Early Solar system was a quite dangerous place, with plenty of colliding objects - so it is possible that life had a chance to start several times, being wiped each time. But this is a pure speculation.
 
  • #25
s0ft said:
So you mean to say that even if the given interval of time is long 'enough', we still cannot be sure that life starts?
If the universe still has a lot to teach us, that can only further justify my point that anything that can happen will, eventually happen. And although I don't and didn't ever mean to say that 'this kind of life' or we 'humans' are the purpose of it all, which I think you believe I have faith in, if you say life can be something entirely different than what we observe, that argument adds to the 'favourable cases' for the chances of origin of 'life', no?
Correct me if I got you wrong.

Our problem is that we only have one example, Earth. With such a small sample our statistical confidence is very low.

You can't say "will eventually happen" because that assumes the universe will las forever. Not it will decay to entropy in time. The hydrogen that powers stars will be used up and eventually it will become very cold. Yes this ail take a very, very long time but a finite time.


We can guess about probabilities. It now seems that most stars will have planets. My guess is that "life", meaning something no more complex than prokaryotic cells may be common but technological societies might be so rare that there is only at most one in the galaxy at any given time. We could very well be the only one. Evidence for this is that (1) life sprung up on Earth really fast, just as soon as conditions allowed. (2) intelligent life did NOT evolve as soon as conditions allowed. and (3) even with humans who could make fire and stone tools, they did this for a million years and never got past that level except for just recently.

So life (prokaryotic cells) happens fast and is likely, but complex life is rare because even on Earth it took billions of years for the first multi-cell life and likely some truly freakish event to create humans.

Another line of evidence is that in only 1,000 years we will likely have the technology to send a robot probe to another star at say 1% the speed of light. At that rate we will have probed the entire galaxy in "only" 10 million years. If technological societies are common then there should be many who are more than 10 millions years older than us, If so then they should have completely colonized the entire galaxy by now even if 0.01c is the speed limit. Earth would have been "discovered" by them multiple times in recent geological history. Even with a 0.001c speed limit we should expect a completely "filled" galaxy. We don't see this. We are likely the first or only society.
 
  • #26
ChrisJA said:
Another line of evidence is that in only 1,000 years we will likely have the technology to send a robot probe to another star at say 1% the speed of light. At that rate we will have probed the entire galaxy in "only" 10 million years. If technological societies are common then there should be many who are more than 10 millions years older than us, If so then they should have completely colonized the entire galaxy by now even if 0.01c is the speed limit. Earth would have been "discovered" by them multiple times in recent geological history. Even with a 0.001c speed limit we should expect a completely "filled" galaxy. We don't see this. We are likely the first or only society.

That or technologically advanced socities are pretty much destined to destroy themselves. I think it's a rational possibility that some sort of time weapon or other not yet understood technology makes self destruction a near certainty for technologically advanced societies. Also it's perfectly reasonable that advanced alien civilizations have found and cataloged Earth, yet we simply lack the ability to detect it. Keep in mind also that at our rate of technological progress it seems very likely society and civilization as we know it evolve into some sort of machines/bionics organization/structure that simply ends up functioning in ways we simply don't understand - this is alos another possible inevitability that could explain the fermi paradox (it's really tough to imagine human civilization 1000 years from now, and I doubt it will be in any major way "human" at that point).
 
  • #27
the overeducated, underemployed scientist speaks

Simon, Chris, and Borek: Good show!

The answer to the original question depends on what kind of life you [here, its C, H, N, O, P, S (macro), and Ca, Fe, and Mg (micro or "trace"); an ambient atmospheric oxidation-reduction potential (for us, it involves O2's reduction to O2- -- like O2 vs. H2O; ours is an oxidizing environment, and oxidation offers more potential options than reduction); and finally, an energy source (remember: redox is known to transform chemical energy into electromagnetic energy, which is the type our form of life uses)]. Oh, and a solvent (here, it's water). There is a relatively high concentration of C in the universe, and it's perhaps the most redox-stable element. C and N both carry information (here, w/in RNA, DNA, and proteins). P is inherently reactive. S is the main element in surface/subsurface soils, because that's simply how Earth turned out. H and O come from the water. These elements are all in the top right-hand corner of Mendeleev's periodic table. The alkali and alkaline Earth elements Na/K and Mg/Ca are abundant in the universe; it turns out that these elements' size (in their ionized form) fits best w/ the informational elements. (Please excuse grammatical errors.) Best of all, these elements can serve as counterions in aqueous solutions. Fe is the most stable element known, for nuclear- chemical reasons I can't explain, and there's a whole lot of it in the universe. Moreover, Fe's a major component of Earth's core. Its job, and Mn's (ever so slightly less stable), is to shuttle electrons (= redox enablers). Current thinking among microbiologists is that life on Earth began when S and Fe entered into a redox relationship. More on that later, but only on request.

Finally, one needs a container to separate life from non-life. A micelle (outer layer of small amounts of fat in water; that's how life on Earth works) or a metal shell [like Fe, which makes lots of insoluble compounds and could have been the original container as a (hydr)oxide] would do. More on that later, but only on request.

Did I remember to say that the energy source was the elements themselves? I'm assuming that there actually was a Big Bang. More on that later, but only on request.

No, NOW finally -- all of these elements must exist as a fluid (liquid or gas), which means that temperature and pressure are important.

Bottom line: life on Earth, beginning w/ single cells (which biologists agree is the fundamental unit of life), came about due to planetary characteristics. Consider: the main solvent on Venus could be sulfuric acid (please consider O's activity before you challenge me; on the gas giants, its could be ammonia; on their moons, it could be methane or ethane. The main informational element could be Si (aren't we already trying to do that right here?). The rest of the macro- and maybe micro- elements could be in the periodic table, immediately below what I listed. The main catalytic element could be Ni (also in Earth's core; in fact, it's the basis of a critical redox activity in the oldest microorganisms, known as Archae) or Mn, depending on redox conditions. The container could be an inside-out micelle: the outer layer of water droplets in oil (highly relevant for the gas giants' moons).

Someone (not sure which thread) asked how you define "life". Tom Brock, a very smart guy, has listed the 7 (? <10) hallmarks of cellular life. Note that cells are defined as the simplest life forms. More on that later, but only on request.

I've read that even Aristotle suggested that there was no clear delineation btwn life and non-life. Viruses (DNA or RNA, +/- protein), viroids (naked RNA), and prions (naked protein) are all informational molecules that infect human cells but cannot replicate on their own, so we know there is quasi-life. Naked DNA is called plasmids, which I think qualify as quasi-life analogous to the 3 forms I just mentioned. More on that later, but only on request.

All you need are the right physical and chemical conditions, in the context of statistical probability and time. More on that later, but only on request. Let's chat?
 
  • #28
more from the overeducated...

Whoops! 1st line should have read "what kind of life you mean".

If interested in a "life from scratch" experiment, please look at the famous Harold Urey - Stanley Miller paper (http://en.wikipedia.org/wiki/Miller–Urey_experiment). It rocked.

You may also want to check http://tolweb.org/tree/ (how life evolved on Earth, Darwin-Mendel style). And/or current thoughts re: the origin, characteristics, and timeline of life http://en.wikipedia.org/wiki/Timeline_of_evolutionary_history_of_life.

So, is there life elsewhere? I personally think so. On Venus, the solvent may be sulfuric acid; on the gas giants (Neptune, Uranus, Saturn, Jupiter) it could be ammonia. On the gas giants' moons, it could be methane or ethane, which could require an outer-layer-of-water-droplet-in-oil micelle.

So it depends on temperature, pressure, available chemicals, fluidity, solvent, and redox conditions. And a very long time. Life on Earth is thought to have appeared ~3.6 billion years ago (Earth is 4.8 billion yrs old, I think). So life happened reasonable fast. Oxygen availability, 2.8 (?) bya. Complex life containing nuclei and itty-bitty organs (per Lynn Margulis, an extremely intelligent woman) appeared ~2.5 billion yrs ago. Multicellular organisms, 1 bya. Fungi, ~0.56 bya. Animals, 0.55 bya. Plants, 0.48 bya. Humans, 0.0002 bya (= 200K yrs ago).

What scientist or group of scientists would be willing to wait millions of years, possibly twice (repeat to be sure), before releasing these data? Publish or perish, I've heard...
 
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  • #29
brendlyn said:
..
What scientist or group of scientists would be willing to wait millions of years, possibly twice (repeat to be sure), before releasing these data? Publish or perish, I've heard...


You are talking abut my probe that takes 10 million years to travel the entire galaxy. I think we will not "send" those probes but maybe the better way to say it is that those probes will decide to leave. We are close now to building intelligent machines. If not in 20 years then in 100 but it will come. The Fermi paradox has only a few answers and it tells us a lot. That people like us are rare.

1) They ARE here but we can't see them
2) Technical societies are very rare, maybe unique. So there is no one to come here.
3) They never came because technical societies evolve into machines who stop caring about planets and just need energy which they get by moving closer, not farther from their own star.

What Fermi tells us is that human-like technical society are very rare and/or don't last long.
So far everyone seem to agree about low-level "life" being so common it is everywhere.
 
  • #30
The Fermi paradox is off topic for this thread, kindly keep conversations relevant.
 
  • #31
Well, thank you all.
I got my answers, actually, a lot more than that.
But the discussion is getting more interesting, let's see how far the radius gets stretched.
 
  • #33
I wish to make two points:
First, I don't believe the chemical pathways that Jack Szostak described are as close to resolving the "Origin of Life Mystery" as his video implies.

The physicist, cosmologist and astrobiologist, Paul Davies reported in his paper titled, "Does Quantum Mechanics Play a Non-Trivial Role In Life?" that "imple calculation shows that it would take much longer than the age of the universe, even if all the matter in the universe consisted of pre-biotic soup, for even a single protein to form by chance..." and that "...the classical chance hypothesis [to explain the Origin of Life] seems unsatisfactory."

Is Dr. Davies correct in his opinion?
Richard Cevantis Carrier (who is an historian and fervent advocate of metaphysical naturalism), reported on 46 "probability of life" studies in a 2004 paper in which Dr. Carrier argued that all of the studies which had rendered the natural origin of life to be statistically impossible (one change in 10 to the 50th power or less) were flawed. Nonetheless, considering that the age of our universe is estimated to be 13.7 billion years (e.g. 13.7 x 10 to the 9 power years) the probabilities that Dr. Carrier reported seem incredibly small:
Barrow and Tipler (1986: 565) one chance in 4.3 x 10 to the 109 power
Borel, cited in Baudin (1962: 28) one chance in 10 to the 50 power
Bradley and Thaxton (1994: 190) one chance in 4.9 x 10 to the 191 power
Bradley and Thaxton (1994: 322–323) one chance in 10 to the 65 power
Bradley and Thaxton (1984: 145) one chance in 10 to the 117 power
Bradley and Thaxton (1984: 146) one chance in 10 to the 45 power
Bradley and Thaxton (1984: 157) one chance in 10 to the 175 power
Cairns-Smith (1984: 47–48) one chance in 10 to the 109 power
Coppedge (1973: 76) one chance in 10 to the 8,318 power
Coppedge (102) one chance in 10 to the 106 power
Coppedge (109) one chance in 10 to the 161 power
Coppedge (111) one chance in 10 to the 119,701 power
Coppedge (113) one chance in 10 to the 35 power
Coppedge (249) one chance in 10 to the 236 power
Coppedge (235) one chance in 10 to the 339,999,866 power
Cramer (1998) one chance in 10 to the 119,701 power
Eden (1967: 7) one chance in 10 to the 325 power
Foster (1993: 79) one chance in 10 to the 650 power
Foster (82, 172) one chance in 10 to the 88,000 power
Foster (39–40) one chance in 10 to the 68 power
Foster (52) one chance in 10 to the 163 power
Guye, via Lecompte du Noüy (33–34) one chance in 10 to the 243 power
Hoyle and Wickramasinghe (1981: 24) one chance in 10 to the 40,000 power
Hoyle (1981: 526–527) one chance in 4 x 10 to the 69 power
Huxley (1953: 45–46) one chance in 10,000 x 10 to the 1,000,000 power
Ludwig (1993: 274) one chance in 10 to the 2,300,000 power
McFadden (2000: 98) one chance in 10 to the 60 power
McFadden (98) one chance in 10 to the 41 power
Morowitz (1979: 99) one chance in 10 to the 399,999,896 power
Morris (1974: 60–61) one chance in 10 to the 53 power
Morris (64–65) one chance in 10 to the 450 power
Morris (69) one chance in 10 to the 299,843 power
Overman (1997: 54–55) one chance in 10 to the 536 power
Quastler (4) one chance in 10 to the 301 power
Quastler (6) one chance in 10 to the 255 power
Quastler (46) one chance in 10 to the 20 power
Quarter (58) one chance in 10 to the 6 power to one chance in 10 to the 30 power
Sagan (1973: 45–46) one chance in 10 to the 2,000,000,000 power
Sagan (45–46) one chance in 10 to the 130 power
Salisbury (1969) one chance in 10 to the 415 power
Salisbury (1971) one chance in 10 to the 600 power
Schroeder (1997: 91–92) one chance in 10 to the 850 power
Yockey (1992: 154–157) one chance in 2 x 10 to the 53 power
Yockey (1981) one chance in 10 to the 60 power
Yockey (1992: 154–157) one chance in 2.3 x 10 to the 75 power
Yockey (1981) one chance in 10 to the 125 power
(SOURCE: R.C. CARRIER, "The argument from biogenesis: Probabilities against a natural origin of life", Biology and Philosophy 19: 739–764, 2004.)

It should be noted that only six out of these 46 studies could support any argument that the natural origin of life was even possible within the time our universe has existed (13.7 x 10 to the 9 power years) with the most optimistic (Quarter, 58) providing a range of probabilities from one chance out of 10 to the 6th power to one chance out of 10 to the 30th power. It would appear that, at best, the probability that life arose naturally in accordance with the conventional scientific explanations is vanishingly small.

Is there an alternative?

I believe that there is, but will require a bounded quantum mechanical model to be introduced.
 
  • #34
What is the reference point for those studies? The probability that life evolves in a finite part of the universe, given our current laws of physics?

- if the universe is not finite, similar everywhere, and evolution of life is possible (we know that part), it will happen somewhere with probability 1.
- if MWI is "true", and evolution of life is possible (we know that part), it will happen.

The "probability" of fundamental constants? Every number is just pure speculation.
 
  • #35
Jacob Bronowski is arguably the coolest scientist to ever walk the planet. He had a good idea that DNA may have been initially formed in Ice. Makes more sense than an underwater thermal vent like we always see.
 
  • #36
Don't you agree?

https://www.youtube.com/watch?v=S8ecCnn5o1o
 
  • #37
The Stanley Miller and Harold Urey experimental creation of amino acids and Leslie Orgel's formation of adenine are necessary constituents of life but do not address the near statistical impossibility that many scientists have calculated for the "Origin of Life" in our universe.
 
  • #38
Their calculations are not worth more than the assumptions made.

But if the aim was to prove the life can't start, doing the calculations is a waste of time.
 
  • #39
Jon_Trevathan said:
The Stanley Miller and Harold Urey experimental creation of amino acids and Leslie Orgel's formation of adenine are necessary constituents of life but do not address the near statistical impossibility that many scientists have calculated for the "Origin of Life" in our universe.

Unfortunatley, as a biologist I have to agree with this. Our presence here is a near statistical impossibility in my opinion. And all those people talking about exoplanets are just pandering to the media. Still, I wouldn't be surprised if we found life on Mars, so I don't think anybody knows
 
  • #40
Paul Davies, in a 2004 paper titled "Does Quantum Mechanics Play a Non-Trivial Role In Life?", has suggested that "Quantum mechanics may offer a radical alternative ...[to the classical chance hypothesis]. Since quantum systems can exist in superpositions of states, searches of sequence space or configuration space may proceed much faster. In effect, a quantum system may 'feel out' a vast array of alternatives simultaneously. In some cases, this speed-up factor is exponential (Farhi and Gutmann, 1998). So the question is: Can quantum mechanics fast-track matter to life by 'discovering' biologically potent molecular configurations much faster than one might expect using classical estimates?"
 
  • #41
Jon_Trevathan said:
. In effect, a quantum system may 'feel out' a vast array of alternatives simultaneously. In some cases, this speed-up factor is exponential (Farhi and Gutmann, 1998). So the question is: Can quantum mechanics fast-track matter to life by 'discovering' biologically potent molecular configurations much faster than one might expect using classical estimates?"

I'm not sure I follow this argument unless it's based on the Many Worlds Interpretation of QM (MWI). Somewhat simplistically, MWI says that all states of a superposition occur, but only one state can be observed to occur in a given experiment. Other states are observed to occur in other "worlds". As strange as it sounds, it's favored by some physicists among those who feel QM needs an interpretation other than the "shut up and calculate" (~instrumentalist) one . How would you apply it here? Do we live in the "world" (represented by a particular outcome of a Markov process) where life as we know it did develop in the time frame we believe applies?

There's no clear argument that this is impossible or even unlikely without resorting to MWI or a role for QM other than its role in ordinary chemistry.
 
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  • #42
DiracPool said:
Unfortunatley, as a biologist I have to agree with this. Our presence here is a near statistical impossibility in my opinion.
Our presence here is, in fact, a statistical certainty: we are here. Otherwise, who are you talking to?

I wouldn't be surprised if we found life on Mars, so I don't think anybody knows
So... our presence is a near impossibility, but life on Mars is unsurprising?

I don't think many biologists still think that classical chance produced life - the "single protein from chance" type calculation are like the "hurricane creates aircraft" argument we get from creationists - with the same counter-arguments.

I think this thread is in the process of self-destructing.
 
  • #43
Thread closed temporarily for Moderation...

EDIT -- Thread re-opened. Thread is being monitored by the Mentors.
 
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  • #44
DiracPool said:
Jacob Bronowski is arguably the coolest scientist to ever walk the planet. He had a good idea that DNA may have been initially formed in Ice. Makes more sense than an underwater thermal vent like we always see.

You do seem to be taking both sides of the issue of the probability of life in the universe. Notwithstanding the obvious fact that carbon based life exists on earth, the question is: Just how rare/common is it in the universe? There simply is not enough data yet to answer that question with any confidence. However it's a fact that important compounds have been discovered in deep space and in meteorites (amino acids, cyclic aromatics, purines, pyrimidines, etc). These compounds are concentrated in water ice under extraterrestrial conditions and were likely delivered to Earth during the bombardment periods. I doubt the the surface of the early Earth was conducive to much ice formation. This should not be confused with the origin of life itself.

Given the availability of the chemical constituents of life and what we know about carbon chemistry, I don't understand this idea that life is such a low probability occurrence.

http://www.astrochem.org/sci/Nucleobases.php
 
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  • #45
SW VandeCarr said:
Given the availability of the chemical constituents of life and what we know about carbon chemistry, I don't understand this idea that life is such a low probability occurrence.

The problem is the (i) "Goldilocks" conditions required for a self-replicating peptide to form, (ii) inherent complexity of all known self-replicating peptides, and (iii) the requirement that the peptide be protected from all degenerative environmental factors until replication, and some evolutionary advances, have had time to occur.

As I noted above, Richard Cevantis Carrier argued, strongly, that all of the studies which I cited above and had rendered the natural origin of life to be statistically impossible (one change in 1050 or less) were flawed. He went on in his paper (on pages 749-750) to argue as follows:

"The appropriate mathematical methods and tools are formally discussed by Küppers (1990) and Kauffman (1993). In general, there are a minimum of five steps necessary.
First, we must identify the smallest possible self replicating protein and identify how many amino acids long it would be (which no one knows, though many guesses have been made).
Second, we must calculate the number of possible ways this many amino acids can be arranged into a string of such a length. Basically, the total t = ns [n to the s power], where n is the number of types of amino acids occurring in nature and s is the protobiont’s minimum length in amino acids. This requires including all the known varieties of amino acids (which is many times greater than the number assumed by all the authors who attempt this …).
Third, we must identify the “viability space” (v), the number of combinations within t that are self-replicating proteins (which no one knows, and no one but Coppedge and Eden have even tried to guess), since the odds of any entity forming by chance c in a single experiment will be v÷t. Almost all the authors who have attempted this have simply assumed v = 1, which is not even plausible, much less proven.
Fourth, we must repeat these three steps for all other protein chains of greater length (which no one has ever even attempted), up to the largest chain that can occur in nature, since we need the sum of all these probabilities, not just one of them. With this (and certain assumptions, see below), we can derive C, the odds of life forming by chance in a single experiment:
C = (vs + vs+1 + vs+2 + ... + vs(max) ) ÷ (ts + ts+1 + ts+2 + ... + ts(max))
Once we have calculated all the viable combinations for all possible natural chains, and divided that by all the combinations possible, we will have the odds that life will naturally arise in a single trial. The final step is to modify that result according to the number of possible trials that have taken place in the available space and time. The more trials, the better the odds. This does not mean on Earth alone, but throughout the whole universe. For instance, McFadden (2000) repeatedly complains about there not being enough materials on Earth to generate one random success, but the early Earth was just one pond among possibly trillions in the cosmos, and only one of those ponds needed to hit upon a successful combination."

In support of his argument that the statistics I quoted above are wrong, Carrier (on page 757) noted the following:
"We have created self-replicating peptides as small as 32 amino-acids long (Lee 1996), demonstrating that the smallest possible chemical that could spark life may be much, much tinier than anything any AFB proponent has assumed possible. McFadden calculates the odds against the Lee peptide arising by chance as 1 in 1041 (1996: 98), which is so far within the realm of cosmic possibility that it is already certain to have happened many times."

However, this statistic assumes the proper allocation and concentration of constituent chemicals and a means to protect the peptide from all degenerative environmental factors until replication, and some evolutionary advances, have occurred. Carrier responded to one of these criticisms as follows:
"And though some argue that cellular structure must also arise coincidentally at the same time, we know life in the right conditions can survive without a cell wall long enough to evolve one (organisms like viruses can survive outside cell walls), and cell-like chambers occur naturally in space (Cowen 2001), and under natural conditions on Earth (e.g. Goho 2003b; Morgan 2003; Horgan 1991: 119, 122), in which living organisms could take shelter, and over which they would gradually evolve a more complex control."
Nonetheless, and unfortunately I cannot find the citation, it is my understanding that these factors would again reduce the probability below 1 in 1050, which would again render the spontaneous generation of life in our universe a statistical impossibility.

This runs counter to my belief that life is common throughout the universe and has been the catalyst for me to look for a possible quantum mechanical solution to the problem.
 
  • #46
SW VandeCarr said:
You do seem to be taking both sides of the issue of the probability of life in the universe.

It's hard not to take both sides. The more I studied molecular biology in college the more astounded I was at the complexity of it all. DNA repair, translation, transcription, second messenger systems, metabolic cycles, etc. It all turned out to be much more involved than I had naively anticipated. I mean specifically metabolic processes that take many steps and have to be performed in specific sequences. It just seemed highly improbable that all this would have happened through chance. But yet it is all around us. So there's your dilemma and why I think its hard not to take both sides of the issue. It's just that it's difficult to wrap ones head around it intuitively.

I think that it will only begin to make more sense if and when we develop a sound model of how life originated, or find life elsewhere in the cosmos. I think we really need to know more about what life actually is and how it begins before we can make a reasonable guess as to how often it may happen elsewhere.

That's why I find origin of life research and discussions interesting. Bronowski's video is admittedly dated, but there's a good deal of current research going on in this area.
 
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  • #47
Theoretically, yes.

But first we need to understand a lot more about the structure and mechanisms of a living cell. We will also need a much higher level of technology. So It's possible. I don't think, however, that we have enough time to attain such a goal. We'll be long extinct.
 
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  • #48
DNA/RNA/proteins? They're puny wimps compared to the amount of information potentially encoded in post translational modifications. The only reason they get so much attention is because humans are good at figuring out codes and manipulating it, sorry life is not so simple. PTMs such as glycosylation are not template driven and can not be predicted so easily like DNA.

Sure, you can produce a protein by manipulating DNA, and have it even fold correctly, however many proteins don't work if they aren't glycosylated correctly. A PTM like glycosylation can control or influence everything from protein function, protein trafficking, cell surface organization, cell-cell interaction, and cell-matrix adhesion.

Carbohydrates and glycans are different than other biomolecules, not only is their sequence important, but so is their 3-D arrangement. Just how much information could potentially be encoded with carbohydrates?

Take for example 3 peptides. They can only be added linearly together, meaning there is only 6 possible combination. If you take 3 sugars commonly used in living organisms, the amount of combinations possible is 25,000. If you just expand that out to 6 sugars, the amount of possible combinations increases exponentially to 1,000,000,000,000 because of the ability of carbohydrates to branch in space. The amount of information that could be encoded in the 'glycome' and the complexity of it makes DNA look like the boy scouts and none of it is template driven. And not only do have the complexity of the glycome to deal with, different biology is achieved by further modifying glycans with other things like sulfation and phosphorylation. The complexity is mind blowing.


Carbohydrates were found in space for a reason...
 
  • #49
The complexity is mind blowing.

That reminds me, I do want to make one important embellishment to one of my earlier posts. I think the seminal (pun intended) problem here is to find out not just how life began per se but just how much of life there needed to be to begin. That's an issue that isn't often brought up if you're catching my drift. There's a bifurcation point between the formation of nucleic acid base pairs, amino acids, etc., and the point where the progressive-generative processes of evolution take over. I think these are the two mysteries we need to focus on. If you haven't read the book "The Sciences of the Artificial" by Herbert Simon, I highly recommend it. He makes a good argument for the almost inevitability of more complex forms arising from simpler ones once evolution takes hold. (But unless you reach that bifurcation point, complex forms tend to devolve due to entropy considerations). The parenthetical expression is my own musing, I don't know if this was in Simon's writings cause I haven't read the book in a while, but it's my personal opinion.
 
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  • #50
I think the ... problem here is to find out ... just how much of life there needed to be to begin. That's an issue that isn't often brought up if you're catching my drift.
You need to get away from the books more: it's brought up all the time - and it is not something that actually concerns empirical science ... it does not matter how much life was needed to kick it off. Empirically, you can only hope to find out how much there actually was. The rest is just math and philosophy.

Consider: It may be that there was more than the minimum "needed". Where would that leave you?
Though - ifaict, the "best models" currently are figuring a minimum life needed to be zero... it's a model that produces a lot of good science, and avoids misunderstanding, and that is pretty much what we need it to do.
 
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