I can't believe abiogenesis

[Prolix]

It's just so.... stupid. That's really all I can say. I mean, it's almost completely impossible. And if it's really not so completely impossible, why hasn't life started with silicon-based life too? I can see the problem creationists have with abiogenesis (but at least I don't think it's the same thing as evolution )

 

Are there any alternatives to the abiogenesis theory for the origin of life?

[Godless Wonder]

Well, some people believe that a super-incredibly-complex creature made of notmatter somehow "created" all matter and life and then disappeared, either went away, or made itself invisible, or is just invisible by virtue of being notmatter.

 

But they don't have much to say about where this creature that created everything comes from ("he was always there") nor can they point him out, or give any evidence at all, whatsoever, that it exists.

 

And, just to be clear, abiogenisis doesn't mean that a fully functional single celled organism with DNA etc, popped into existence one day. Probably something much simpler. It's not clear exactly what the first life form looked like. Nobody claims to know this information. It's not clear how unlikely or likely it is either. It only had to happen once though.

 

Life is here, we can see it, and there was evidently a time when life was not here. Either the life we can see was created by some other life that we can't see, (which came from where? Oh, it just happened?) or the life we can see managed to just happen (via abiogenesis + evolution.)

 

So, your choices are between

 

1) abiogenesis -- some as yet unknown, but fairly simple -- certainly not intelligent -- probably just a handful of atoms in all -- arranging themselves into a pattern which could, influence other atoms to arrange themselves in an identical, or nearly identical pattern. (Something like how the prions which cause mad cow disease are a "wrongly" folded form of a protein which, upon bumping into "rightly" folded forms, transforms them into the "wrongly" folded kind -- something along those lines.)

 

2) Some unknown and unknowable, entity which must be more complex and strange than anything anyone has ever seen anywhere, and more complex than everything anyone has ever seen anywhere all put together "just exists" and "creates" by some unknown, and unknowable process all the stuff that we can see, yet this crazy thing which is posited is itself undetectable, and BTW, no fair asking where it came from, because who the hell do you think you are, mister! (And they typically tack on a lot more silly rubbish onto this invisible creature as well.)

 

Why don't we see abiogenesis happening again today? a) it's incredibly rare, Likely, on earth, it would be eaten almost immediately by some existing life, or at best, not very well suited to compete, having to start literally from square one. c) where should we look, exactly?

 

How is abiogenis more stupid than (or even as stupid as) door number 2? Door number 2 simply moves the problem where it cannot even be looked at, and supposes that the even more complicated unseen life managed to "just happen." So, door number 2 includes abiogenesis as a part of it.

 

You have no choice but to accept abiogenesis, since both doors contain it. Door number two just supposes that abiogenesis managed to create a life form which is capable of creating an entire universe and life within it, separate from itself.

 

I think part of the problem is that the human idea of what is likely and unlikely is very bad when it comes to extremes. An extremely low probability event, which only needs to happen once, given enough time, and enough trials, so long as that probability is not exactly zero, will eventually happen. The universe is freakin' huge.

http://antwrp.gsfc.nasa.gov/apod/ap040309.html

That is the Hubble ultra deep field image. If you look through an eight foot long soda straw, and point it in any direction into the sky, and you could see as well as the Hubble, what you'd see is something like what's above. There are about 10000 galaxies in that picture, each galaxy will millions upon millions of stars. If you wanted to photograph the entire sky though your eight foot long soda straw, you'd have to make millions of photographs to cover the whole sky. The universe is a very big place, and has been around for a very long time. Your intuitive sense of "extraordinary odds" is not equipped to deal with this amount of space and this amount of time.

[Wertbag]

Basically we are all built of the same naturally occuring chemicals, its only a matter of figuring out what process combines the existing chemicals to form a building block of some kind.

There are several different ideas that have been put forward from the energy released from undersea volcanoes to lightning strikes on existing chemical soups. Basically the theory says a large amount of energy is required to cause chemicals to bond together, and this situation occurs naturally and constantly.

 

The events required happen in parallel (eg lightning strikes many places at the same time world wide) and in great numbers over long periods of time. All it takes is the right combination... this is the main arguement against, that the odds are too small to make it believeable. Of course small odds happen all the time (eg lotto), and if you remember parallel tries its not as bad (eg buy 1 lotto ticket and you have a 1 in 7,000,0000 chance, buy a million lotto tickets and suddenly its 1 in 7000, repeat at those odds for several years and its only a matter of time).

[crazy-tiger]

It's just so.... stupid. That's really all I can say. I mean, it's almost completely impossible. And if it's really not so completely impossible, why hasn't life started with silicon-based life too?

Almost completely impossible means that it could happen... and with the size of the universe, it's gonna happen somewhere.

 

Meanwhile, your second question was worded wrong... it's not a question of why it hasn't, but more a question of if it has, why haven't we found it?

Considering the size of the universe, (yes, consider it again ) it's basically guaranteed that it's happened somewhere... and still considering the size of the universe, (I know... but it's important :happy_old: ) it'd be one heck of a miracle for us to find any evidence of it.

 

 

 

Come to think of it, didn't they find silicon-based life back in the 60's?

[pandora]

Pehaps life can ONLY arise from carbon based chemicals in the conditions that were present at that time... perhaps that is why we aren't silicone based. There are natural laws... maybe that is just one of them.

[Mike D]

All it takes is the right combination... this is the main arguement against, that the odds are too small to make it believeable. Of course small odds happen all the time

I agree with this. There are things in nature like a perfect storm, or other occurances that are rare, or extremely rare. But when the right combination of factors come together unusual things can happen. Why is it so hard to believe that these extremely rare events can't happen elsewhere in the universe? Also, I know some people find it hard to believe that life on planet earth would be the only life in the universe, but I actually don't find that so hard to believe, if we are here as the result of a "perfect storm" of sorts, that maybe only occured in one small corner of the universe.

[MrSpooky]

People often mistake evolution (the production of new species and the change of certain populations) with abiogenesis (“life” from “non-life”). Evolutionary biology has nothing to do with abiogenesis, but evolutionary mechanisms can still explain it by providing a model.

 

The common model of abiogenesis is this: Amino acids are formed from simple chemical processes using only some water, minerals, and energy (heat, lightning, radiation). The amino acids eventually, out of mere chance, eventually chain up to form proteins. These proteins, out of mere chance, eventually chain up to form a fully functional bacteria.

 

But this common model of abiogenesis is wrong. No evolutionary biologist supports this mechanism, despite what we see in Star Trek. It is due to this reason that many find a naturalistic explanation for the origin of life difficult to fathom, that there exists a certain “leap of faith” between “life” and “non-life.” Some Intelligent Design supporters have likened the process to a tornado striking a junk heap and arranging a perfectly functional 747. But this analogy, while quite good at explaining the fallacies of the common view model of abiogenesis, is a straw man argument. It has nothing to do with real biology or the relevant biochemistry.

 

Currently, the best model in biology goes like this: in the primordial beginnings of Earth, the condensation of water and the release of carbon-rich organic chemicals as well as nitrous elements formed a pool of simple chemicals. These simpler chemicals, with the input of energy from heat, radiation, and lightning, form more complex organic chemicals, such as nucleotides and amino acids.

 

The famous Miller-Urey experiment did this very thing. In a reconstructed “primordial environment” of water, simple minerals, chemicals, and gases in a glass jar, with the addition of small charges of electricity, the necessary chemicals of life are easily formed. While the initial gaseous environment of the Miller-Urey experiment in actuality did not ideally model the environment of primordial Earth, follow-up peer review experiments were later performed under a huge range of environments and chemical ratios that were much more accurate to our best estimates of what the earth was like long ago. All the necessary amino acids and nucleotides were easily created in such environments.

 

Now remember that natural selection is very powerful, and for natural selection to occur, one must have a self-replicating structure to act upon. Thus, at some point in time, there came the rise of a self-replicating molecule.

 

I sense the incredulity here. While this seems to be a big step from simple chemicals to self-replicating molecules, it really isn’t that big of a deal on the chemical level. Crystals self-replicate. Clays self-replicate. Very simple compounds can self-replicate, and in this manner they convey their own patterns from one generation to the next.

 

Self-replicating molecules, of course, require simpler components: materials to build themselves up from, and unfortunately there is a limit to how much raw, simple chemical “food” these molecular critters have in their oceanic environment. Thus, we have a selective mechanism. With a self-replicating structure and a selective mechanism (the limit of “food”) we have evolution.

 

As more and more chemical “food” is used up, selection would favor the molecular critters that are better suited for existence. Some molecules have catalytic components that can break down and cannibalize other molecules (and in a way become chemical “predators”) while molecules that are more stable against catalysis, such as ring structures, are favorably selected (and thus become better-protected “prey”). Remember: there is no really good definition of “life:” depending on how you define “life,” anything from the most complex human to the simplest of reproducing chemicals can be considered “life.”

 

At some point in time, our chemical critters, now self-replicating polymers, get encapsulated in a lipid bilayer membrane, like a cell. Again, this sounds incredulous. Where did these little guys get the mechanisms to form such a membrane? The best answer is: they don’t.

 

Lipid bilayer membranes are formed from phospholipid molecules, which have the special property of naturally forming lipid bilayer membranes when placed in water. It doesn’t take much for bubbles to form and encapsulate our polymer critters and protect them from other carnivorous polymer critters.

 

This structure, what we call a “probiont,” is the intermediate structure between self-replicating polymers and bacteria, the simplest form of modern life. A bacteria is simply a very complex polymer within a lipid bilayer membrane, with other functional chemicals.

 

At some point in time (where in this process is unknown), RNA had piggybacked on the self-replicating structures, forming RNA chains. RNA is just another polymer, nothing special, and chemically has been shown to be capable of self-assembly and self-replication. It is the basis of life as we know it. RNA would have eventually led to DNA with the advent of transcriptase proteins that help DNA replicate. RNA and DNA are both polymers capable of replication, but they also have the added benefit of the ability to make proteins, which give the organism more complexity.

 

So here is the mechanism in review: Simple chemicals produce organic chemicals, which can polymerize to form self-replicating polymers. These polymers were encapsulated in a lipid bilayer membrane to form a probiont, a precursor to bacteria. At some point in this process, nucleic acids piggybacked on the polymers, forming RNA, which is itself a self-replicating polymer. With RNA and a lipid bilayer membrane, and the addition of some random proteins, the first prokaryote (bacterium) was formed. Is it the correct model? Maybe not. But the point is that the concept of abiogenesis being inconceivable within our current framework of biochemical understanding is fallacious. We have a perfectly functional model and easily conceivable model that fits in with our current understanding of biochemistry.

 

And thus, we have the gradual, step-by-step development of the first prokaryote: the first single-celled organism. Nothing magical, nothing special, nothing mysterious. The whole thing is elegantly and functionally explained by simple biochemistry: it’s that easy for life to form from non-life within a few million years.

[HuaiDan]

My thought on why we don't see carbon based life:

If carbon based life existed anywhere in the universe except in our solar system, we wouldn't know about it yet. We're just now getting fuzzy images of super huge planets in other star systems. It'll be awhile before we'll be able to detect the presence of tlife on these planets, if ever.

Given the conditions abiogenesis of carbon based life occur with astronomically low frequency in the universe, the abiogenesis of silicon based life must also be comparatively astronomically low. The probability of them occuring on the same planet would approach the product of both events occurring seperately.

For example, if the probability of Carbon abiogenesis were 1/10^30, and that of silicon based abiogenesis were 1/10^20, then the probability of both of them occurring in the same place would approach 1/10^50, with numerous other factors fine tuning the value. Which is to say, such a scenario may indeed occur somewhere in the universe.

[Vigile]

 

Damn! This is proof that you rockers are able to use the left sides of your brains as well. Beautiful post.

[Saviourmachine]

It's just so.... stupid. That's really all I can say. I mean, it's almost completely impossible. And if it's really not so completely impossible, why hasn't life started with silicon-based life too? I can see the problem creationists have with abiogenesis (but at least I don't think it's the same thing as evolution )

 

Are there any alternatives to the abiogenesis theory for the origin of life?

Any alternatives to "the abiogenesis theory" would also be called "abiogenesis theories", so I think you try to ask for alternatives to some specific abiogenesis theory. In that case I want to know what you understands as "the abiogenesis theory".

 

Computational autopoiesis tries to find the theoretical basis that can account for the self-replicating and self-organizing systems we nowadays observe. This site describes the original algorithm of Varela. A name you should remember when you decide to know more of this stuff. It's a computer simulation of a very simple environment with only three "molecules". When you run this simulation you can see that these will form a circular chain (a cell). The cell wall is maintained automatically. And no specific algorithms are designed to keep it that way. It's all embedded in the binding characteristics of the "molecules". Such a system could arise also in the wild, but I'm not familiar what is and what isn't found yet. The self-forming cellular structures that are found seem to grow infinitely. And in stead of that they should be stable and form more complex systems or they should be able to split in two new cells.

 

Because of this lack of evidence - in the real world - I respect your lack in belief in this theory too. Or maybe Spooky knows more about reproduction of probionts.

[Zach]

I'd second MrSpooky on this one, and also recommend the first few chapters of Richard Dawkins' The Selfish Gene.

[Megistias]

And, just to be clear, abiogenisis doesn't mean that a fully functional single celled organism with DNA etc, popped into existence one day. Probably something much simpler. It's not clear exactly what the first life form looked like. Nobody claims to know this information. It's not clear how unlikely or likely it is either. It only had to happen once though.

 

 

Why couldn't it be happening all around even now ?

 

We'd probably have a hard time detecting it anyway. Your "Probably something much simpler" wouldn't stand a chance for very long in our predatory microbial world honed by billions of years of competition for resources.

 

In other words, what ever a key precursor to new life might look like, it's probably SLOW and DELICIOUS to existing life forms.

[trashy]

http://antwrp.gsfc.nasa.gov/apod/ap040309.html

 

Dude, I LOVE that pic. It's my new desktop wallpaper. I think I'm going to try to get it in poster form or something. That's what I want in my Home Theater on my walls......

[Samurai Tailor]

It is a category mistake to say that abiogenesis is likely or unlikely or much of anything, really. The term does not describe any particular theory, but a field of study that includes all possible pathways from non-life to life.

 

Thus, while the RNA world is an abiogenetic theory, it is not abiogenesis in toto.

[All Gods Fail]

As far as the odds go, Prolix, remember that the vastness of the universe acts as a multiplier. In other words, the larger the space, the higher the likelyhood a given factor could happen.

 

Or as Penn Jillette once observed, "In a town the size of New York, a million to one odds happen 10 times a day."

[Dio]

This was speculated concerning abiogenesis:

Why couldn't it be happening all around even now ?

 

In other words, what ever a key precursor to new life might look like, it's probably SLOW and DELICIOUS to existing life forms.

Being a complete novice concerning evolution and abiogenesis, I have what might be an ignorant and certainly highly-speculative question. I appreciate anyone's response.

 

I was reading about common ancestry at www.ebonmusings.org:

If one extrapolates backwards far enough, it is possible to show that all organisms alive today have a single ancestor in common, a simple unicellular organism that probably existed between four and five billion years ago, from which all modern life descended and diversified. This is known as common descent and constitutes the final major component of evolutionary theory.

 

Ok, if abiogenesis might have happened more than once, then might there be multiple origins to earthly life? In other words, could insects have descended from one occurrence of abiogenesis and other species have descended from another ultimate source?

[Samurai Tailor]

Ok, if abiogenesis might have happened more than once, then might there be multiple origins to earthly life? In other words, could insects have descended from one occurrence of abiogenesis and other species have descended from another ultimate source?

Almost assuredly not. With astonishingly few exceptions, codons code for the same amino acids in every instance. And, given the centrality of hereditary information to evolution, it is exceedingly unlikely that independently-arising organisms were able to pick up DNA/RNA some time into their existence. No, chances are DNA/RNA existed long before the first cell.

[txviper]

"No, chances are DNA/RNA existed long before the first cell"

 

 

By way of luck formation? Well when do you suppose the replication enzymes and proteins came into the picture? DNA/RNA are, amazing molecules, but they don't reproduce themselves without these incredibly complex control agents.

[Mr. Neil]

Well God must have done it then.

 

Go ahead. Attack a strawman now.

[Cerise]

I agree with this. There are things in nature like a perfect storm, or other occurances that are rare, or extremely rare. But when the right combination of factors come together unusual things can happen. Why is it so hard to believe that these extremely rare events can't happen elsewhere in the universe? Also, I know some people find it hard to believe that life on planet earth would be the only life in the universe, but I actually don't find that so hard to believe, if we are here as the result of a "perfect storm" of sorts, that maybe only occured in one small corner of the universe.

 

I'm not sure if abiogenisis has to do with a dust cloud forming life as we know it or not, but my brain cannot fathom life from nothing, I don't know why I have so much trouble seeing that. In the same token though, I can see why it SHOULD BE hard for me to conceive of a higher life form being responsible.

 

It may be wrong, but I'm just being honest with myself. In all honesty, I just don't know.

 

Well if you're thinking of it as LIFE ---------->NOTHING equation then it is completely understandable that you are fiinding it hard to believe.

 

But it's never been that kind of equation, in my understanding. Lots of little chemical reactions over lots of time had to happen before we get to LIFE (and why must it be as we know it?) from nothing.

[MrSpooky]

By way of luck formation? Well when do you suppose the replication enzymes and proteins came into the picture? DNA/RNA are, amazing molecules, but they don't reproduce themselves without these incredibly complex control agents.

 

I'm pretty sure it was mentioned earlier in the thread that RNA is auto-catalyzing... that is, RNA not only contains information like DNA, but it also has the ability to perform molecular functions like proteins.

 

So RNA has the capacity to be its own "complex control agent" before DNA and protein are introduced.

[MQTA]

And, just to be clear, abiogenisis doesn't mean that a fully functional single celled organism with DNA etc, popped into existence one day. Probably something much simpler. It's not clear exactly what the first life form looked like. Nobody claims to know this information. It's not clear how unlikely or likely it is either. It only had to happen once though.

 

 

Why couldn't it be happening all around even now ?

 

We'd probably have a hard time detecting it anyway. Your "Probably something much simpler" wouldn't stand a chance for very long in our predatory microbial world honed by billions of years of competition for resources.

 

In other words, what ever a key precursor to new life might look like, it's probably SLOW and DELICIOUS to existing life forms.

 

How would we know? When we find a new life form we have no records of, does it mean we never found it, or does it mean it 'just happened'?

 

Is the question out of our realm of consideration, is it how does life begin anywhere in the universe? we could never know from our point of view. Or is it how did life come to this planet?

 

To think perhaps the human species came here from elsewhere in the universe is one thing, but then what about all the rest of the creatures, microscopic to gigantic?

 

Perhaps the Earth didn't have an atomosphere as it does now, so when it was just a ripe little egg, there was no life here. Then comets hit the Earth with dna from elsewhere in the universe, life started to form and the planet Changed. What landed here grew and evolved but the conditions for new life had changed and stopped.

[Dark Helmet]

Perhaps the Earth didn't have an atomosphere as it does now, so when it was just a ripe little egg, there was no life here. Then comets hit the Earth with dna from elsewhere in the universe, life started to form and the planet Changed. What landed here grew and evolved but the conditions for new life had changed and stopped.

 

But then that only begs the question : where did that alien dna come from and how did it form?

[MQTA]

 

 

But then that only begs the question : where did that alien dna come from and how did it form?

 

Well, alien or no, the age and size of the universe is so far out of our grasp, it's virtually eternal no matter how you slice it.

 

We're only talking on matters of Scale.

 

If aliens brought or changed the life on this planet, then they'd have to obviously come from another planet.

 

Either way, if God, whomever it is, supernatural or just alien, was not from Earth, then he's an Extra-terrestrial. Either way.

 

But on the grand scale of the universe, using a telescoping method, the aliens would have come from another planet elsewhere in the universe. That planet would have it's own history with a similar, yet different, type of beginning.

 

Who knows... it's sufficiently in our past and larger than we can grasp, or ever know, or even know if we did find the truth in all the potentials.

 

Begging questions are plentiful, we'll always have a lot more questions and multiple potential answers for all of them.

 

*TILT*

[scitsofreaky]

It seems to me that abiogenesis is like the lottery. For each individual (planet) there is almost no chance of winning, yet every so often someone does and inevitably will because of the number of people playing. Does this analogy make sense?