The Origin of Life: A Scientific Inquiry

[Desiree]

Where did "life" come from?

There is something about this "big bang" theory that makes me not to accept it at all and that's: Life. Physicists have all tried to put together their observations and I mean observations only to come up with this big bag theory, but at the same time there exist animate and inanimate, both made out of atoms and molecules. So far so good, makes sense, but my question is: Is animate's structure and existence exactly the same as the inanimate's? How is it possible that life = the initial micro organism from which everything evolved including us humans- EVER existed within that big bang tiny tiny spot under infinite temperatures and pressures? These are the reasons I have that makes me believe that the "big bang" theory is NOT correct and something else must have existed/happened in the distant past as 'life phenomenon' does not fit into that theory. What do you think?

 

[vociferous]

Life is composed of the same star-stuff as the rest of the universe. The big bang was far too hot for matter to exist in the forms we commonly see it. It took a long time for the heavy elements that are required for life on Earth to be created.

But ultimately, everything in the known universe is made up of the same materials, materials which may have metamorphosed since the big bang, but were ultimately derived from it.

 

[Kurdt]

Big Bang theory doesn't attempt to answer the question of where life came from. It merely explains very well the observations we make today about the universe. I don't know why you think there were any micro-organisms around at the time of the big bang. .

 

[MeJennifer]

I think this question would be more appropriately handled in the chemistry/biology section of this forum.

 

[Desiree]

"Big Bang theory doesn't attempt to answer the question of where life came from.."

Well it should. Because it says everything came from that tiny tiny tiny dot thing. and everything means EVERYTHING. I don't intend to mix the role of "God" or anything supernatural in the big bang but the question of life's origins still persists? If life's initial form could have withstood or come from the same big bang, then it should be proved if life is capable of withstanding that infinite temperature and pressure to still live on and evolve billions of years later...any comments now?

 

[Moonbear]

"Big Bang theory doesn't attempt to answer the question of where life came from.."

Well it should. Because it says everything came from that tiny tiny tiny dot thing. and everything means EVERYTHING.

No, it shouldn't, and doesn't. Life came along much later after things had changed quite a lot from the original formation of the universe. The Big Bang theory only addresses how the universe started, not how things progressed once the universe got its start. It's somewhat the way Evolutionary Theory only addresses how things have evolved AFTER life started, and also doesn't address how that life actually came to exist. Abiogenesis (the formation of life where none existed before) is still poorly explained by science. There are theories around about it, but strong evidence is lacking.

 

[jim mcnamara]

You have conflicting assumptions. Life is made from molecules. Life does not come in some pre-existing form. The molecules have to exist first, without life around to use them.

You are taking 'everything' far too literally. The big bang explains the origin of matter and the universe. Life evolved here on Earth billions of years after the big bang. Using the matter left over from stellar explosions - supernovas. That where the elements with atomic numbers higher than iron come from - gold nickel selenium, etc. Some of these higher numbered elements are part of living systems.

 

[Brin]

I might be oversimplifying - but atoms make up the universe, molecules are a collection of atoms in a neutral state, life as we know it is made up of systems of molecules.

Life stems from atoms - which came into existence with the big bang, no?

 

[nicksauce]

This is like saying that you don't accept Freud's theories of psychology because they don't explain how airplanes fly. One has NOTHING to do with the other. Theories cannot be criticized for not explaining things that they don't try to explain or that aren't in their scope. There is plenty of research in trying to figure out the origin of life, but it is completely separate from big bang cosmology.

 

[Integral]

I might be oversimplifying - but atoms make up the universe, molecules are a collection of atoms in a neutral state, life as we know it is made up of systems of molecules.

Life stems from atoms - which came into existence with the big bang, no?

Yep! You are oversimplifing. The BB examines how the atoms came to be. The period covered by the BB ends when the universe as we know it is in place. Life formed long after that.

 

[vociferous]

I might be oversimplifying - but atoms make up the universe, molecules are a collection of atoms in a neutral state, life as we know it is made up of systems of molecules.

Life stems from atoms - which came into existence with the big bang, no?

Yes and no. Yes, atoms come from material originating from the big bang, but no in the sense that it took some time for the material that comprises the observable universe to cool to the point where atoms could coalesce. In the stage prior to the creation of atoms, there should have been some kind of expanding soup comprised of quarks, leptons, and energy. Once they expanded far enough that they could cool, atoms would have been formed.

 

[Brin]

Ah many thanks for the clarifications. So then the question is - what caused these atoms to coalesce as they do?

Is it possible that it is also happening somewhere else in the universe? Or were these conditions a one time special thing?

 

[vociferous]

Ah many thanks for the clarifications. So then the question is - what caused these atoms to coalesce as they do?

Is it possible that it is also happening somewhere else in the universe? Or were these conditions a one time special thing?

When particles' energy levels are high enough, then the electrical or nuclear bonds tend to no longer hold them together. If you heat a gas, eventually the electrons have so much energy that they break loose from the electromagnetic force of the nucleus and the substance becomes a plasma. If you heat the plasma up it could break down further and eventually become a soup of quarks and leptons, as even the strong nuclear force would not e enough to hold the atoms together.

Essentially, during the early stages of the big bang, the matter produced by the big bang was so close together and so energetic that the strong nuclear force could not have pulled the subatomic particles into atoms. As the matter spread apart and cooled, the strong nuclear force would have started pulling together subatomic particles into larger particles such as protons and neutrons, and eventually atoms.

 

[Brin]

(side question: is this how the LHC is planning to work? Not by super heating, but by pretty much crushing two atoms together and, I assume THIS is what the recreating of the events of the big bang would be?)

Specifically, however, I was wondering what caused the atoms to come together to form molecules that function as they do? I have very little Physics, and no biology education, so I'm just kinda exploring realms I probably have no business in yet - but I am curious. Atoms all by themselves seemingly have no "function" persay, but the combination of them into molecules almost kind of give them one, but its not until they start forming cells that they have some sort of active "function," i.e. they are reproducing and doin' the stuff that living things do. I'm just curious at what point does a collection of functionless pieces become something that IS functioning? I assume it's like my computer - In pieces its useless, just a collection of nice looking junk - together, and with a flow of electricity it is a wonderful device.

 

[Mike H]

Specifically, however, I was wondering what caused the atoms to come together to form molecules that function as they do? I have very little Physics, and no biology education, so I'm just kinda exploring realms I probably have no business in yet - but I am curious. Atoms all by themselves seemingly have no "function" persay, but the combination of them into molecules almost kind of give them one, but its not until they start forming cells that they have some sort of active "function," i.e. they are reproducing and doin' the stuff that living things do.

What causes atoms to come together is a matter of chemistry. Chemical bonds are made, chemical bonds are broken, molecules interact, other molecules interact.

Ascribing a putative purpose to some entities and not to others in biological systems is a tricky one. Ethylene is just two carbon atoms and four hydrogen atoms, but is an important plant hormone. Complexity is a matter of perspective - there are well-known oscillating chemical reactions that can be induced by light and can generate patterns. But it's just a mixture of rather typical laboratory chemicals.

I'm just curious at what point does a collection of functionless pieces become something that IS functioning?

This is the crux of much research being done in abiogenesis. There are plenty of ideas being bandied about on a variety of issues involved in abiogenesis.

 

[Andy Resnick]

There is no scientific definition of what constitutes 'living matter' as distinct from 'nonliving matter'. Until that is done (and this should be a priority), there is no way to answer the OP.

 

[Count Iblis]

I've read that comets could have played an important part. Comets contain a lot of organic materials. Suppose some comet is kicked out from the Oort cloud. It then approaches the Sun, heats up a bit and then moves away from the Sun and cools down again. When the comet is closest to the sun, it is still very cold inside, but hot enough for some chemical reactions to start to take place.

These chemical reactions are very different than what you can get in a test tube on Earth. In the comet due to the low temperatures, a molecule will react with whatever molecule happens to be sitting next to it. After many orbits around the Sun, the comet's orbit changes and it spends a longer time closer to the Sun. The temperature rises and then many molecules that have been cooked up decay. Some molecules that have been formed will be very stable. The intermediary steps that led to the formation of these stable molecules may well have involved molecules that would be unstable at the current higher temperature of the comet.

These more stable molecules can now start to react with molecules that are a bit further away due to the higher temperatures, forming more complex molecules. As the orbit of the comet's orbit is perturbed more and the comet spends more time closer to the Sun, these more complex molcules are again selected for stability.

Since closer to the surface of the comet it is much warmer than in the deeper parts of the comet, the different phases of this process are going on at the same time.

Suppose that the comet crashes into the Earth at a very oblique angle. Then the contents of the comet can survive the collision. Some of the complex molecules that have been cooked up in the comet will be able to survive the environment on Earth.

 

[BoomBoom]

Specifically, however, I was wondering what caused the atoms to come together to form molecules that function as they do?

Keep in mind that before you can even have the chemical interactions that form molecular compounds, you need to have different types of atoms. In the beginning there where would only have been hydrogen atoms. You need stars to form and for those stars to go supernova in order to form the heavier elements (carbon, nitrogen, oxygen, etc.) that life would require.

 

[George Jones]

I've read that comets could have played an important part. ...

Comet stuff used to be considered "out there", but this view has gained a least some respectability when combined with other approaches. http://news.nationalgeographic.com/news/2003/10/1002_031002_cometstudy.html" is somewhat dated National Geographic news article about a NASA project. I am not sure of its present status.

 

[Andy Resnick]

None of these comments address the important difference between organic molecules (i.e. containing carbon, maybe an amine group) and catalytic or replication function. A lump of glucose will sit there. A lump of RNA will perform a specific function, and can also replicate.

The origin of organic molecules is not that interesting- immense clouds of orgainic compounds are out there. Glycine- an amino acid- has been found in space. Far more interesting (IMO) is the origin of replicating molecules (i.e. RNA). Nucleic acids have not been detected in space, AFAIK.

 

[BoomBoom]

A lump of RNA will perform a specific function, and can also replicate.

Only with the proper associated enzymes is this true...a lump of RNA by itself will remain a lump of RNA.

Which brings us to another tantalizing question: which came first? The template to make the enzymes, or the enzymes responsible for giving the template funtion? I would assume you would need the amino acids to randomly assemble into a functioning enzyme before anything meaningful could take place...IMO. While RNA and DNA may hold the code of life, the code is meaningless without enzymes that perform the functions.

 

[Desiree]

I don't believe in BB in the first place. I don't believe atoms and molecules got together and bonded all by themselves and formed life. Life's initial formation is even more complex than anything imaginable. Maybe the story did not begin as BB says it did. Why should we stick to this BB theory and expand on it while we could have been wrong all along. I do respect the research and studies that have been going on over the past couple centuries to eventually come up with the BB, but I do not think atoms spontaneously came together and started feeding on each other, then started evolving into other forms...up to today's forms...atoms and molecules feel pain, go hungry...sleep...study physics and biology to only discover that they came from a disastrous explosion...BB! these are a few of countless reasons I have that make Big Bang invalid to me.

P.S.
Someone moved this thread from 'Cosmology' to 'Biology'. I am not arguing with biologists over the validity of the BB theory and this should be moved back to Physics/Cosmology I suppose.

 

[BoomBoom]

Someone moved this thread from 'Cosmology' to 'Biology'. I am not arguing with biologists over the validity of the BB theory and this should be moved back to Physics/Cosmology I suppose.

The topic "where did life come from" belongs in biology. If you want to ask questions about the BB theory, then you may do so in the cosmology forum.

As has been pointed out by others in this thread, the two topics have absolutely nothing to do with each other. So if you want to discuss life then this place is appropriate and the BB is appropriate in cosmology, but it doesn't make much sense to merge the 2.

 

[George Jones]

I don't believe in BB in the first place. I don't believe atoms and molecules got together and bonded all by themselves and formed life. Life's initial formation is even more complex than anything imaginable. Maybe the story did not begin as BB says it did. Why should we stick to this BB theory and expand on it while we could have been wrong all along. I do respect the research and studies that have been going on over the past couple centuries to eventually come up with the BB, but I do not think atoms spontaneously came together and started feeding on each other, then started evolving into other forms...up to today's forms...atoms and molecules feel pain, go hungry...sleep...study physics and biology to only discover that they came from a disastrous explosion...BB! these are a few of countless reasons I have that make Big Bang invalid to me.

P.S.
Someone moved this thread from 'Cosmology' to 'Biology'. I am not arguing with biologists over the validity of the BB theory and this should be moved back to Physics/Cosmology I suppose.

It seems to me that you have problems with two quite different things, the origin of life and the origin of the universe. I am a physicist, and the last time I studied biology was many years ago in high school, so I'll try and address only the second point.

As we go back further and further in time, conditions in the universe become more and more extreme - high energy and high density. Eventually, we reach a time where our best current physical theories break down. We are working hard to extend our theories; this is what research (in any field) is about.

In a few years we might have a theory that shows that we were silly to consider the Big Bang a problem. Or we might have a new theory for which the big bang is still a problem, but the problem occurs earlier in the universe than our present theories can handle. Or some other scenario of which I cannot think.

Remember, this a science forum, and only the science of the "big problems" can be discussed here.

 

[Count Iblis]

A replicating primordial soup may have evolved long before RNA developed. So, perhaps you would have enzymes that catalize other enzymes which in turn catalyze yet other enzymes etc. etc. making the whole soup of enzymes to be able to maintain itself and grow. Darwinian evolution can already work in an inefficient way in such a situation.

 

[vociferous]

You seem to be dealing with two different and unrelated issues: biology and cosmology.

I think if you look at the big bang, it does not satisfactorily answer questions like: how old is the universe? How was the universe created? But, it is the only satisfactory answer to a lot of evidence, like the continual expansion of the universe and ancient high temperatures. There really is no competing explanation.

As for abiogensis, or the formation of life from nonlife, this is unrelated to the big bang. Life on Earth started billions of years after the big bang. Abiogensis does not satisfy everyone, but it does answer the question "how did life begin on earth" much more satisfactorily than other theories.

 

[baywax]

There is no scientific definition of what constitutes 'living matter' as distinct from 'nonliving matter'. Until that is done (and this should be a priority), there is no way to answer the OP.

The differences between living and non-living matter begin to show us the "constitution" of each.

Crocheters of a living matter are:
1- Nutrition (feeding).
2- Breathing.
3- Growing.
4- Multiplication (increase in number).
5- Movement.
6- Death or degeneration.
The reverse is true fo none living.

http://answers.yahoo.com/question/index?qid=20080207064636AA4esL3

Here's another observation concerning the differences between living and non-living matter.

Hi Don
It certainly seems hard to tell at times especially by just looking at something. I expect that prehistoric humans thought fire was a living thing. Butlife forms have special characteristics that non living things do not. For one thing they are cellular in nature. They move, grow, reproduce and respond to the environment and they change over time. Moreover living things metabolize. That is they incorporate substances into their bodies and they convert these materials into their own substance. I consume the animal proteins and I change them into my own proteins.

The question "What is life" is difficult to answer. So in science when confronted with "big" unanswerable questions we substitute small questions we can answer so we ask ourselves "what do we mean by the term " living"? Then we come up with the actions that I mentioned the key one being Metabolism. The reason a virus is not considered to be living is because it has no metabolic process.
The difference between living and non living is sometimes blurred. A sequoia tree is a living organism but 99% of it is dead non-living stuff.
Look up James Lovelock and the Gaia hypothesis. Lovelock considers the Earth itself to be a self regulating organism and he has some very convincing arguments.

http://en.allexperts.com/q/Biology-664/Living-nonliving-matter-1.htm

But the OP asks where did life come from and that can be answered with several theories. Many think life began as a few well placed nucleotides next to an oceanic, volcanic flume. There had to be some sort of mud capsules within which the materials of life could be contained. Conditions for the formation of life may have a small range of flexibility but they must always have some sort of overall stability and be free of the risks of catastrophe... to some degree. This is one reason that life probably didn't start developing and evolving until around 3 billion years after the Big Bang.

Now, you might say, where is that life from 10 billion years ago? And it may still be out there but, more than likely it has succumbed to the types of catastrophic changes that take place over 10 billion years. So, you have to see life as starting and ending in the many different sectors of this universe. In our own area of the universe it is thought that life began around 3.5 billion years ago. Its thought that the life on this planet started here, but that can not be proven beyond a doubt.

What about the resilience of life? Life is very resilient. It survived the asteroid or comet that hit Earth 65 million years ago. This incident lit the whole planet on fire, but life crawled out from under whatever shelter if found and carried on.

 

[Andy Resnick]

Only with the proper associated enzymes is this true...a lump of RNA by itself will remain a lump of RNA.

Which brings us to another tantalizing question: which came first? The template to make the enzymes, or the enzymes responsible for giving the template funtion? I would assume you would need the amino acids to randomly assemble into a functioning enzyme before anything meaningful could take place...IMO. While RNA and DNA may hold the code of life, the code is meaningless without enzymes that perform the functions.

That's not true- some RNA is autocatalytic; it is itself an enzyme:

http://biology.plosjournals.org/perlserv/?request=get-document&doi=10.1371/journal.pbio.0030310&ct=1

Thus, one emerging thought is that RNA is the basis of life; DNA follwed after RNA.

Stuart Kaufman has written an excellent book specifically addressing your second paragraph.

 

[Andy Resnick]

I don't believe in BB in the first place. I don't believe atoms and molecules got together and bonded all by themselves and formed life. Life's initial formation is even more complex than anything imaginable. Maybe the story did not begin as BB says it did. Why should we stick to this BB theory and expand on it while we could have been wrong all along. I do respect the research and studies that have been going on over the past couple centuries to eventually come up with the BB, but I do not think atoms spontaneously came together and started feeding on each other, then started evolving into other forms...up to today's forms...atoms and molecules feel pain, go hungry...sleep...study physics and biology to only discover that they came from a disastrous explosion...BB! these are a few of countless reasons I have that make Big Bang invalid to me.

<snip>

This point of view to completely anti-science. Sentences such as "[...] is even more complex than anything imaginable." are written by people who disapprove of scientific inquiry. Claiming to respect "research and studies" when you believe certain things are beyond understanding is ridiculous.

Either come up with a plausable alternative that can be falsified, or admit to yourself that you don't understand the point of scientific inquiry.

 

[Andy Resnick]

The differences between living and non-living matter begin to show us the "constitution" of each.

I don't understand whatyou mean by "constitution".

Here's another observation concerning the differences between living and non-living matter.

A definition is not a list. As for that list, it is satisifed by a fire. Is a fire living? The quote you give even mentions fire, but then confuses the issue by using the phrase "special characteristics" which is left completely undefined. Fires move, fires metabolize food and breathe air. Fires excrete waste products. The quote even goes on to add additional valid and blurry statements- a living tree is composed of 99% dead matter. Meanwhile, the term 'dead' hasn't been defined either.

This isn't an excersise in pedantics. This is a central issue upon which molecular biology rests, never mind ethical considerations. Obviously something differentiates living and non-living objects: the ability to heal and recover from injury (among other things). Think about what it would mean if we could quantitatively understand 'healing' and then apply it to any material object we wish? The fact that work is already underway in this regard only underscores the fact that defining these "special characteristics" is very important and something to be seriously studied rather than dissmissively waved off. A single cell can detect the presence of multiple chemicals; measure temperature, viscosity, compliance; and then perform a decision-making process resulting in target acquisition, capture, and elimination. A single cell.

Tell me that understanding how all that functionality gets packaged into a few cubic microns has no paractical application. My claim is that developing this technology and understanding the science demands that we have a good definition of 'life'.

[/QUOTE]