Issues with Origin, Part 1: The Suddenness of Life

[blike]

Originally posted by spuriousmonkey

people are starting to doubt this notion, because there is uncertainty now that the earliest microfossils are really microfossils. Instead they are just remnants of the primoridial soup. The first real genuine known microfossils are therefore not from around 3.8 billion years ago, but something like 2.7 billion years.

 

If this is true than life didn't just appear. It took actually quite some time. About 1.5 billion years since permissive conditions for life arose.

 

If they're questioning the dating, then it is possible that there was a long intermitant time. I havnt' seen any source for this though, and it seems to be widely accepted the oldest microfossils are around 3.5 billion years old.

 

http://www.ucmp.berkeley.edu/precambrian/archaean.html

http://www.emc.maricopa.edu/faculty/farabee/BIOBK/BioBookPaleo2.html

[spuriousmonkey]

i'm not in this field of research, therefore I relied upon a popular science journal for this information:

 

New scientist

27 february 2003 page 28-31 'proof of life'

 

but apparently there is some dissent about the nature of these first microfossils.

[Glider]

I'm not really sure why time is an issue. If there are an extremely high number of possible chemical combinations, and only one that would lead to life, then we might expect it to take a long time to occur. However, if the combinations are occurring randomly, then each combination (including repetitions) has an equal chance of occurring at each trial. Therefore, the probability of the 'viable' combination occurring first, is the same as it occurring last (or at any other point in the series). This assumes the combinations are occurring in series. If we assume that these combinations are occurring in parallel (i.e. as many 'trials' at once as there are possible combinations, as seems likely), then we might expect the time required to produce a viable combination to be significantly reduced, even taking into account repetition of inviable combinations. This principle would apply to each step in the many that would have been required to result in the first 'proto-cell'.

 

By this reasoning, there is no particular reason to expect it to have taken billions of years, whether it actually did or not; we have just as much reason to ask "why did it take so long?" as "why did it happen so quicky?".

 

As soon as a particular combination occurred that, through some peculiarity of it conformation, had a propensity for self-replication, randomness would be reduced as the process is now limited to a much narrower set of possibilities and each trial would result in an exact (or close) duplicate of that first combination and we now have a 'driving force' (the chemical attraction to the specific molecules required for replication, plus the odd replication error, some of which would have been, by chance, advantagious) and we may reasonably expect the process to accelerate as all the previous possible but 'irrelevant' combinations would be eliminated from that particular set.

 

It's only a thought.

 

I've heard of the 'seeding' idea which suggests that organic life may have come to Earth in cometary detritus or in a metiorite, but that still leaves a problem, in that it must still have originated somewhere.

[spuriousmonkey]

i guess the timeframe can be an issue if you would ask the question. Was the creation of life a straightforward inevitable event or not? The longer it takes for the first life to appear the more likely the possibility is that the chances for life to occur are lower than we previously thought. It is more like a small shift of perspective than a new idea blossoming.

[Radical Edward]

Originally posted by Glider

I've heard of the 'seeding' idea which suggests that organic life may have come to Earth in cometary detritus or in a metiorite, but that still leaves a problem, in that it must still have originated somewhere.

 

furthermore, there probably isn't just one way in which it could come about.

 

re: seeding. while life would still have had to come about somewhere, seeding would mean that there is alot more stuff for life to come about it, and alot more time for it to happen in, again increasing the probability.

[DocBill]

Originally posted by fafalone

What are the odds of chemicals naturally combining to form life?

1 in a billion?

1 in a trillion?

 

Every galaxy has billions of stars, the universe has billions of galaxies. Would the odds catch up sometime?

 

something to think about.

 

In a reducing atmosphere with H20 in a vapor or liquid form, about 1/10,000

 

Bill

[Radical Edward]

Originally posted by DocBill

In a reducing atmosphere with H20 in a vapor or liquid form, about 1/10,000

 

Bill

 

anywhere in the universe? or just earth, given the constituents and early atmospheric conditions

[Ryoken]

Why is water such a critical component? Because of the hydroxide molecule or simply due to the properties of hydrogen?

[fafalone]

Because of the properties of water itself. High heat capacity, cohesion, hydrogen bonding, solvency, etc.

[blike]

What are the odds of chemicals naturally combining to form life?

 

What are we calling life here..

[fafalone]

If the odds were one on 1 billion... that's still a great chance.

[YoungStrife]

On waht period of time with what sized planet with what atmosphere, how much water, and how much heat?

 

Could we replicate the joining of protonsinto the double helix of DNA?...Is it possible?

 

Europa can have life and titan is gettin there in just a billion years...yay....we'll have friends

 

P.S. Why does anything alive want to live or reproduce? And how could just a few prioteins cause that?

[greg1917]

with so many chemical factors i think the odds would be extremely long, where did 1/10,000 come from? that seems small in the grand scheme of things.

[Radical Edward]

Originally posted by YoungStrife

Could we replicate the joining of proteins into the double helix of DNA?...Is it possible?

 

P.S. Why does anything alive want to live or reproduce? And how could just a few prioteins cause that?

 

1) by random chance, certainly, but it would take a while. life is thought to have come about via RNA first though, not DNA.

 

2) because if it doesn't it dies out and something that does 'want' to reproduce carries on a genetic line of other things that want to reproduce. for somple organisms though, reproduction is a more mechanical process. desire doesn't come into it.

[M-CaTZ]

Wald's article was replubished 25 years later in a 1979 special edition Scientific American. However, this time the article appeared with a retraction.

Replubished? IM not the only one who makes typos blike.

Anyways, the issue of origin of life has been a subject of controversey for thousands of years. Ofcourse, the more advanced society gets, we apparently get "closer" to the answer. However I for one being a pragmatist on most issues, feel that We are digressing further from the truth as more and more scientific explanations come along. On this particular topic I have to support the idea that a Supreme Being is responsible for the creation of life. I'm not saying that all of the scientific theories are not plausable, however after reviewing some of the probabilites posted on this site and other sources, it doesnt seem very likley. Ofcourse i could be wrong, and who knows maybe someone in this forum could come uip with the truth of life. You never know:D

[Skye]

You can't really fault the origin of life by chemical processes on probabilty while believing a supreme being created life, since I can't see a way of calculating the chance of a supreme being even existing.

[blike]

Originally posted by Skye

You can't really fault the origin of life by chemical processes on probabilty while believing a supreme being created life, since I can't see a way of calculating the chance of a supreme being even existing.

 

Very true.

[aman]

Looking at basic evolutionary life through electrical engineering, it seems the first step in evolution would be to build an amplifier. "Life" previous would blossom or die due to chance. True life would build an amplifier to detect traces of remote locations of needed resources.

We are evolved amplifiers of very limited ranges in five directions.

We took a DNA route to sentience building our amplifiers. Anywhere we see amplifiers we see the potential for life if combined with a storage of energy. That's about as basic as it gets but looking at it this way it is easy to visualize life forming on many levels other than our distinct organic.

Just aman

[Giles]

blike said in post #1 :

Harold Morowitz, in his book "Energy Flow and Biology" computed that merely to create a bacterium would require more time than the Universe might ever see if chance combinations of its molecules were the only driving force".

That's a completely irrelevant calculation, since no one is suggesting anything as large as a bacterium formed by chance. the probability of (for example) an autocatalytic ribozyme is quite a lot higher. Depending on how suddenly life appears, and how closely the microfossils resemble modern organisms, it might not be so implausable. Lipid bilayers can spontaneously assemble quite easily.

[VendingMenace]

Hey all, it is my first post, so i just thought i would say "hi" to start things off...

 

What are the odds of chemicals naturally combining to form life?

1 in a billion?

1 in a trillion?

 

given a few assumptions this shouldn't be too hard to estimate. At least i don't think. perhaps i will give it a shot later on in this post

 

Every galaxy has billions of stars, the universe has billions of galaxies. Would the odds catch up sometime?

 

Well then that depends on the odds in the first place don't they?

 

That's a completely irrelevant calculation, since no one is suggesting anything as large as a bacterium formed by chance. the probability of (for example) an autocatalytic ribozyme is quite a lot higher.

 

Cool, lets look into the assembly of a small protein then, shall we? It is not quite hte same as the ribozyme, but i feel that it is a simpler case to consider, and the pricinples should hold true.

 

Lets make a bunch of assuptions to make it really easy for the protien to be formed. Lets first assume that it is a really small protien, lets say 100 residues. Then lets also assume that this protien is already made in its random coil form. That means that we are assuming that all the amino acid residues are in the right order for the protien to be active (wich would be a big issue anyways, but we will accpet, for some reason, that this has already happend). Now then, after all these assumptions all that remains is for this protien to fold from random coil into its active conformation. Given all the other assumptions taht we have made, i feel it is ok to assume that there is only one conformation that is active. OK, lets check out the folding process.

 

So, basically, there are three functional motifs within protiens, the alpha helix, beta sheet, and reverse turn. So, in order to benifit the protien even more, we shall assume that there are only three different conformations possible. Right? OK then we find that there are 3^100, or 5.15 x 10^47, different conformations.

 

Cool lets assume then that a protien can go through 1 millioin conformations a second, so that means that to check these all out, it would take 5.15 x 10^41 seconds. Given that there are 3.15 x 10^7 seconds in a year, it would then take 1.63 x 10^32 years to go through all the possible conformations.

 

Alright, lets give our little protien the benifet of the doubt and say that it finds it right conformation in the first 0.1% of the possible conformations (very lucky!). It would still take 1.63 x 10^29 years for the protien to assume its active conformation. Needless to say, this is a long time.

 

All this is just for ONE small protien. Take into consideration that even the simplest forms of life have many protiens in them and we are looking at a time required for making these proties that is many orders of magnitude greater than the age of the universe.

 

This is not really a consideration of probability, at least not strictly. However, i think that if one can show that a process should take longer than the age of universe, then it is unlikely that it would occur anywhere, no matter how many planets there are.

 

Alright you say, numbers are all well and good, but obviously protiens do not take this long to form in the body, or we wouldn't be here. Right, there are things called chaparones that help in the folding process. Of course, back in the day, these would not have existed. Whats more, these would have had to be formed out of random chance in the begginning too.

 

Now i am not saying this disproves that life could arise out of nothing. After all, it is possible, right? Just very unlikely. Anyways, just saw peole werer asking about odds and the like, and i thought i would add my two cents. COol.

 

Lipid bilayers can spontaneously assemble quite easily.

 

True, but they do not have the confomational complexity found in protiens or the ribozyme. They are held together through hydrophobic interaction and van der waals forces. They do not have to explore a plethora of conformations in order to be functional. At least that is kinda how i see it.

 

Anyways, these forums look like fun. I think i will enjoy sharing ideas with you all

[Sayonara]

You're right, that's not a consideration of probability.

 

Nice post though - I found it interesting. Welcome to the forums!

[NavajoEverclear]

Yeah welcome to the forums, but don't be offended it i don't have the attention span to read your post (i think audio would be easier for me absorb, but reading certain things just makes my brain fry), i'm sure its cool though.

 

Hey Blike I read that you believe in God, so how do you fit in your belief with all the science that people say means he doesn't exist? I believe in God too, just curious how you work things out in your head. Are you one of the people that believe God willed evolution to occur? I think that God being human and already in existence would simply have started Adam and Eve with his wife like mortals do (and my religion believes God also has a physical body, unlike most believing he is only spirit)---- but then that conflicts with Jesus being his ONLY begotten son.

---------- so just wondering what you think about all that, or if what you believe doesn't have anything to do with that, just curious.

[Glider]

Welcome to the forum. Good first post too!

 

Cool lets assume then that a protien can go through 1 millioin conformations a second, so that means that to check these all out, it would take 5.15 x 10^41 seconds. Given that there are 3.15 x 10^7 seconds in a year, it would then take 1.63 x 10^32 years to go through all the possible conformations.

 

This assumes the protein starts with an 'incorrect' conformation, and goes through all possible 'incorrect' conformations, ending with the 'correct' conformation. If the process is random, there is just as much chance that it could find the correct conformation in the first trial (one millionth of a second), or at any point in the series. Therefore 1.63 x 10^32 years is only the last of a huge number of possible times to the correct confomation, and is just as probable as one millionth of a second. If the process is random, there is no way to determine how long it would take.

[aman]

If the calculations are for one pool of water, it may take eternity, but if you calculate pools of water over a planet simultaneously, then the odds get a lot better. There's a lot of molecules and energy reactions happening at the same time on the surface of a planet.

Just aman

[Skye]

To me, the moral of the original post is to remember that we have very sketchy evidence of the state of the world 4 billion years ago, especially at a microscopic or molecular level, and it's dangerous to calculate the probability of anything from that data.

 

Example: What's the chance of the world's mountain ranges being where they are today based on the known geology or geophysics of the Earth at 4 billion years ago?