Time is by far the worst explanation I have ever heard for this phenomenon. If you want to assume the lightning --> primoridal ooze --> amino acids scenerio, consider this:
The experiment that created amino acids also created a tar biproduct that would have destroyed the next steps required for evolution. Even if the tar didn’t form, to make a protein, amino acids have to bond. Yes, they are to some extent polarized, but the formation releases water. By Le Chatelier’s principle, if the AA were in an excess of water to begin with, the likelihood of a peptide bond forming would be very small, and chances are any free floating protein would have been broken down.
And again, for an AA to form, there are two forms (L and D), and ONLY L forms work in life. This means that whatever time it would take now doubles. You have to first imagine the time to randomly create one L AA, then the 19 others required to again randomly form a protein. The protein must be randomly combined with other randomly created proteins to somehow make a ribosome. This then has to randomly match up with randomly created RNA in order to somehow make new proteins.
Ribosomes are made of of TWO segments that have to perfectly match. One has 45 proteins and 3 molecules of RNA, the other has 33 proteins and one molecule of RNA.
Also, the second law of thermodynamics states that for a reaction to be spontaneous there must be a net release of free energy. All of the random processes require a certain amount of energy input (someone mentioned that above). In the body, these processes require proteins and ATP/GTP to overcome the energy problem.
Thank you for your advice on finding text books. However, I currently own a $150 biochemistry book, a $120 cell biology book, a $160 organic chemistry book (with study guide), two books on evolution, and I live accross the street from a bookstore and a library. None of this can account for how a protein could randomly form at the same time and place that RNA randomly forms in such a way as to start making new proteins.
That depends on what you mean by recreate in a lab. We can’t recreate a hurricane in a lab, but we understand the way hurricanes get started and can model this on a computer in a lab. I can’t think of millions of such natural phenomena, but I can think of a few. None of the ones that I can think of have a very strong foothold in demonstrable science, as of yet. However, you miss my real point, we don’t really know so we shouldn’t talk about it as if we do!
Spiritus Mundi writes:
Touche’. Since we cannot demonstrate that it can actually occur, the probabilities are not measurable. So for the sake of argument, I’ll call them zero… not it’s up to you to present scientific refutation that these odds are invalid.
I have a thought experiment for you. Let’s say I have six pennies in my pocket and you’ve got six coffee cups. In a couple of random experiments we determine that I can heave a penny about 50 paces. But my accuracy sucks because (1) pennies are not aerodynamic (2) wind and other environmental factors impinge on the airborne pennies and (3) I’m a terrible shot! So I stand still while you walk away from me 50 paces and set down one of the mugs. I heave a penny at the mug and low and behold, my throw is perfect. I have just the right distance, just the right angle of attack, just the right spin to put the penny in the mug. I walk to that mug and you walk another 50 paces to set down another mug. I repeat my toss with unprecedented and unerring accuracy. Repeat. Repeat. Repeat. Repeat. Six tosses - six bull’s eyes. Would you require the precise probabilities of this sequence of events before you would declare that this was an unlikely scenario?
whoa! rarely have i seen people so completely wrong. lets start with JoeyBlades. first of all, RNA is NOT made of peptides. there are absolutely ZERO amino acids in RNA. it is simply made up of four bases and a sugar-phosphate backbone. all of these can form spontaneously from basic ingredients and energy. some of these have the property of self-replication, and were able to form membrane (seperate but equally spontaneous process) bound capsles of RNA. contrary to what Matt MacKinnon feels, it is not likely that ribosomes (NOT the same as ribosymes) as we know them today formed from this process. they are complex structures that likely formed after organisms switched their genetic storage device from single-stranded RNA to more stable double-stranded DNA, and switched primary enzyme function from RNA-enzymes (i.e. ribosymes) to amino acid based enzymes we know as proteins. these proteins also had the ability to be used for a huge variety of other uses and allowed organisms utilizing them to proliferate profusely. the presence of RNAs in ribosomes today (rRNA) and their important role in building amino acid chains (tRNA) indicates their historical function as being fundamental in the processes of the cell. whew, now my fingers are tired, so i’m going to stop with that. if any further clarification is needed, do not hesitate to ask.
[paraphrase]
JB: The odds are astronomical so I say abiogenesis didn’t occur spontaneously.
SM: Care to supply those odds and how you derived them?
JB: I can’t. I will call them 0. Now it is up to you to demonstrate I am wrong:
[/paraphrase]
Hard to argue with logic like that, isn’t it? How about if I simply note that JoeyBlades has no basis for making an argument reliant on probability. I am not surprised. The position “I believe this and you have to prove me wrong” does not depend upon probability. The natural counter, of course, would be “Spontaneous abiogenesis is inevitable given the Earth’s ecological history and the time fram involved. I have no numbers, but I assume the probability aapproaches 1. You have to prove me wrong.”
No doubt both positions deserve equal consideration in the fight against ignorance.
The thought experiment, of course, is irrelevant to this discussion since the model fails on numerous levels. Taken simply on it’s own, though. I would reserve judgment on the odds until I had had you heave a large number of pennies at my coffee cup and determined an emirical basis for the assignment of odds. Alternatively, any guess I made would depend upon the reliability of your assertions that:
pennies are not aerodynamic.
wind and other environmental factors impinge on the airborne pennies.
[you’re] a terrible shot.
If you made 6 bulls-eyes in a row I would feel obliged to examine each of those assertions carefully, though I could not dismiss out of hand the possibility that something quite improbable had just occurred.
The best lack all conviction
The worst are full of passionate intensity.
*
One argument I recently heard went through the chances that a computer could randomly make a page of text that was legible. By this I mean randomly going through all of the key stokes over and over again to make one page of text with proper spelling and punctuation. {it kind of goes back to the monkeys writing Shakespeare} This is just soooo unlikely, and it gets even worse if the computer also had to make sure the letters weren’t upside down! But not only does the computer have to make a page, several computers would some how have to each make a page that matched up at the same time AND location.
That’s the idea behind 20 AA’s randomly forming THEN randomly combining to make a protein that randomly matches up with another protein INSIDE a membrane. We’re going beyond probability and statistics. At what point could we conceive that randomness just isn’t a valid answer. It’s one thing for someone to repeatedly get a penny in a cup, but consider if you had to first reach in and either pull out a penny or a nickle (only the penny works) each time, and your buddy had to do the same thing at the SAME time in the same room!!!
I got the following from a very unreputable source but it makes a good point:
Consider that there are 10^20 conceivable interatctions betweeen subatomic partics per second. And that in theory there are 10^84 particles in the universe, and since the dawn of time there has supposedly been about 10^17 seconds. This gives a total of 10^121 events. A molecular biologist by the name of Harold Morowitz claims that the total number of events necessary to produce a single living cell ar 10^100,000,000 thus dividing 10^121 by 10^100,000,000 you get 0.
I’d also like to appologize to bryanmcc, I assumed you had spelled rybosome wrong. Which brings up an interesting point, what came first, RNA or proteins?
Biogenetic theories are like cosmology. We have no direct evidence of the sequence of events that led up to the phenomenon we call “life”. The best we can do is concoct more or less plausible scenarios. As we learn more about biogenetic chemistry, we will be able to eliminate more theories as either impossible or seriously implausible.
However, in the meantime, we have some basic facts, and we can use them to argue some simple interpretations.
Fact 1: Life exists. Therefore it must have come from somewhere.
Fact 2: Many astonishing things have arisen from demonstrably natural processes.
Fact 3: No evidence exists that any phenomenon has arisen from supernatural or divine processes.
It’s not a proof, but the above facts seem to argue for a natural process of biogenesis.
Until there’s significant evidence to the contrary, you’re free to believe in divine origins for life, but you can’t make a rational argument against a natural process from originally non-living matter based on our ignorance of the process. We can assign no relevant probabilities to the chances that life arose from self-replicating molecules. We don’t know all the relevant factors.
But what we do know is that every phenomenon we example closely and been able to make any kind of determination as to its cause, we have always found a natural process. We have never found a phenomenon where we could rule out every natural process, or where we could plausibly attribute it to a divine or supernatural process.
I think the burden of proof is on the divine theorists to rule out every possible natural process or show direct evidence of a divine or supernatural process.
The “probability” argument for divine origin is fatally flawed. True, modern proteins, RNA, an other biological molecules probably did not arise spontaneously; however, we have incomplete understanding of the probability of a self-replicating molecule of some sort. Any simple self-replicating molecule, once a single instance spontaneously assembled, would by definition become very become ubiquitous. At that point, natural selection provides a method of incrementally building structure until we have modern life.
And I have already mathematically proven that even a simple process of natural selection can reduce a probabilistic task by more than 60 orders of magnitude. Throwing around minute probabilities is simply showing ignorance of basic mathematics. Like other rationalists, I’m willing to listen to a reasonable argument, but I have little tolerance for willful ignorance.
Prove that no simple self-replicating molecule can spontaneously assemble, and I will give the divine origins theory more attention.
Time flies like an arrow. Fruit flies like a banana.
It just keeps getting better.
Computers printing letters “upside down”?
A lovely association of the chance for spontaneous abiogenesis with the chance of random page of characters producing a grammatically correct text (is language important?)
Why that “example”? Why is that moel more relevant than the probability that sunlight refracting off of particulate matter in the atmosphere will produce an image of startling beauty?
Indeed. That point being: disreputable sources rarely provide reliable informarion.
I do not know what you think those numbers imply, but if you want to apply them to spontaneous abiogenesis then you need at a minimum to address:
The definition of “event” used in deriving each number.
A demonstration that the definitions used in each case are equivalent for computational purposes.
A demonstration of how Mr Harold Morowitz arrived at his very interesting number.
A demonstration that Mr Harold Morowitz’ number applies only to random abiogenesis not planned abiogenesis (otherwise you would seem to e implying that life is impossible because not enough events have occurred in teh life of the universe for the first living cell to have formed.)
BTW
No. You have never entered the field. You have usurped some of the jargon without bothering to conform to the requirements of the field.
“Do the math” != “type a few numbers”
Please, if you want to argue from probability, do the math.
The best lack all conviction
The worst are full of passionate intensity.
*
Single Dad: I don’t recall anyone arguing that divine intervention was involved. In fact, I specified in my original post that I didn’t want to hear anything religious.
What is comes down to is that the theory of evolution by natural selection does not completely account for abiogenesis. I was wondering if anyone had any ideas on how to refine or revise that theory to account for the early beginnings of life.
1.) the probability of abiogenisis is at least very very low.
2.) Since no actual scientific laws are violated, said probability is is greater than zero.
3.) given enough time low probability events can occur.
4.) SOMETHING obviously happened, since here we are.
5.) That something is either
a.) an extraterrestrial or supernatural cause or
b.) abiogenisis from random combinations of materials on the prebiotic earth.
6.) there is no evidence for thing a.
7.) How thing b came about is still a matter of speculation but numerous diverse theories abound (See Casti’s book mentioned above for an account of the controversy.)
Now is there anyone out there who knows enough about this subject going to describe the possible models for abiogenesis, or is this non-biologist going to have to plow through Casti again, do a web search and post a flawed and probably erroneous answer to the OP?
One final point about probability, though discussions of probability are a distraction from the main thrust of the OP. not only are we dealing with a lot of time we are also dealing with a lot of space. There are a lot of stars out there. There could concievably be planets with the right ingredients for abiogenisis where the combinations did not occur.
It’s like the lottery. Odds against winning are so low you are throwing your money away. Yet, somone does win.
Which, of course, is and, given our understanding of physical processes, has almost certainly always been abundantly avaiable on the Earth. I have a few trillion photosynthetic and chemosynthetic organisms that will agree with me.
Which shows a basic miscomprehension of chemistry. Atoms do not combine randomly, but according to the number of electrons, or opportunities for accepting same, in their outer shells. Amino acids do not combine randomly, but according to their three-dimensional structure (and, as bryanmcc points out, were probably not involved in the first quasi-organisms anyway).
Some posters overlook a Gouldian element of randomness in abiogensis. Why those twenty amino acids? Why those five bases in NAs? Why is *ATP{/i], not GTP or some chemical compound, the common “energy currency” of terestrial life? Why that particular relationship of codons to amino acids? (Hint: this last is a red herring; we know of two different codon/AA relationships.) The probability of an event that has occurred is always 1.00…; the real question is, “What is the probability that a given set of initial conditions will lead to life?”. To answer that question, we need: 1) actual samples of alien life (performing arts majors do not count in this context), or; 2) a “quantum biochemistrry” that would allow us specify the answer from first principles. We do not have either.
“I don’t just want you to feel envy. I want you to suffer, I want you to bleed, I want you to die a little bit each day. And I want you to thank me for it.” – What “Let’s just be friends” really means
I have spent four years studying molecular biology, and I would LOVE a plausible scenario that can go from AA generation to a single celled organism–especially one that did not involve the phrases infinite time, random chain of events, or Bible.
Some one mentioned the problem of recreating the events in a lab. There are a lot of biochemical reactions that scientists can’t even come close to duplicating–the reason is that they are looking at the most COMPLICATED reactions possible. If AA joined spontaneously, that would be the most BASIC of all reactions. Its one thing not to be able to make a hurricane, but its another not be able to make wind.
The argument that keeps using random chance with infinite time is really, really silly. It actually bothers me that scientists would use that as an argument. They begin to sound as illogical as creationists. The idea of scientific explanation requires for more than:
Lightning struck a pool of ooze
2.) AA~{!/~}s formed
3.) A bunch of stuff happened
4.) A bunch of stuff happened
5.) A bunch of stuff happened
6.) Then there was life.
All that~{!/~}s missing is a booming voice directing it to happen. We should know better than to use to illogical statements to justify an outcome (zero probability and infinite time). In theory, you could save money on the photocopy budget by watering down the toner, and to compensate for the watered down toner, set the copier to ~{!.~}dark.~{!/~} (Scott Adams)
All that’s missing is a booming voice directing it to happen. We should know better than to use two illogical statements to justify an outcome (zero probability and
infinite time). In theory, you could save money on the photocopy budget by watering
down the toner, and to compensate for the watered down toner, set the copier to
‘dark.’ (Scott Adams)
Not so. The half-lifes of assembled protein and nucleic acid in water are on the order of thousands of years.
**
Uh, not exactly. It’s not as though the L form waits around while the D form takes its turn. You’re also forgetting that either form will work- only one is found in living things, but working proteins can be made from D amino acids. (By the logic of your argument above, one could argue that the presence of D and L amino acids halves the time, since you get two chances!)
**
Actually, ribosomal RNA retains 70% of its protein-synthesizing capacity in the absence of protein.
[/B}
Actually, the processes require ATP- the protein merely channels the energy. You’re also assuming that since ATP is used now, then it was a requirement for early life. You might as well assume that people couldn’t buy anything in the Middle ages, since the dollar hadn’t been invented yet.
**
Just out of curiosity, what are the titles of all these books?
Well, of course not. One can’t expect textbooks to address straw-man arguments.
-Ben (who is, incidentally, a molecular biologist.)
Actually, it’s already been explained in this thread that it doesn’t account for it at all, any more than organic chemistry deals with nucleogenesis in first-generation stars.
Well, you said that with such authority and I, not being a biologist, don’t have the background to refute it… so I can only conclude that nearly every source that I’ve consulted on the subject is wrong.
Spiritus Mundi writes:
Careful with that brush Eugene. That’s not what I said at all. Allow me to paraphrase:
I think the odds, based on our current theories and understanding, are extremely low. Therefore I am not assuming that the abiogenesis theory is valid. It’s entirely possible that, at some later date, science will have a better picture of the physics and chemistry that may have been present at the genesis that bring the odds more down to Earth.
But I’m not saying you’re wrong. I’m only saying that you have no evidence that you’re right and that, from all the evidence we have today, abiogenesis seems like a long shot. Of course long shots pay off.
No real argument here. It wasn’t meant to be analogous to abiogenesis, per se, though I’m sure I could make it fit better if I tried.
Ahhh… This points out the real flaw in my thought experiment, because you’ve missed my point. Let’s say that instead of you being the guy who was placing the coffeee mugs and therefore being a witness, someone else placed the mugs. Then you and a fourth person come along and the other guy sez, “Hey check out these pennies in these mugs. I’ll bet that some guy threw the first penny from over there somewhere and it landed in the mug. Then he threw the next penny from this mug to the next one and so on.” Would you consider that a plausible theory?
SingleDad writes:
Well, color me stupified… Your post is the first in this thread to talk of devine or supernatural intervention.
Brilliant! So you hope to improve the odds by adding more independent variables, more degrees of freedom? Have you ever played pool? Is it easier to make a two ball combo or a three ball combo?
You keep saying that, however natural selection is an invalid argument for the steps up to and including the genesis. Natural selection is only relevant for organisms that reproduce. Get me to the point were we have that first self replicating organism, then I’ll consider your natural selection argument.
Spiritus also wrote:
Gimme a break. I’m betting that some of the ‘science’ that you take for granted is based on similar arm waving. For instance, do you buy into the Drake equation for the probability of life on other worlds? Where did Dr. Drake come up with his probabilities? I can come up with more examples of ‘questionable’ statistics used to validate scientific principles if you’d like… Hell, some of them I even agree with!
Larry wrote:
Bring me your evidence for thing b please.
Yeah, but was it time enough and were there enough suitable environments to beat the odds? I don’t think we’ll ever be able to answer those questions.
ERic MacKnight wrote:
This is exactly my point. I was not saying that just because we can’t duplicate it in a lab it never happened. My point is that because we can’t duplicate it in a lab, it’s complicated and (I know this is a bit of a leap), if it’s complicated it probably has a lower probability of occuring spontaneously.
Exactly! This has been the core of my argument from the start.
