Were electromagnetic forces the first impulse for life? (Microbe-type.) If so, how could that have come about without the components needed to interact? And were their staggered developments pre-life?
The short answer is we don’t know for sure.
If electromagnetic forces were required, there’s plenty of that out around the gas giants, along with lots of lovely soupy wet chemical environments - and there is transfer of material between there and Earth.
Not saying that’s how it happened, but it could be.
Everything is electromagnetic forces.
OK, that’s not quite true. Gravity isn’t electromagnetic. But everything else you’ve ever experienced, everything you can directly detect in any way and most of the things you indirectly detect, are all electromagnetic. Look at your computer, feel the keys under your fingers, smell it… Those are all electromagnetic interactions.
I think the OP is probably thinking about strong magnetic fields, induced currents, etc.
Thing is, whatever the required conditions for the rise of proto-life, the universe is big and complex enough that the combination will exist somewhere. And if the conditions for life to start and those necessary for it to continue are different, then there will be places in the universe where those conditions exist in reasonable proximity to one another.
(And that’s all on the assumption that there are any singular specific conditions. It may be that there are lots of different ways it could happen).
An “impulse” for life sounds as if it is buying into the idea of some sort of vital force. As Chronos says, for all useful purposes, after gravity, everything we experience is electromagnetic. Linus Pauling got the Nobel for showing that all chemistry is described by Quantum Electro-Dynamics, and that is still just electro-magnetism with a fancy name.
The traditional explanation for the precursors to life (the Miller Urey experiment) had lightning or other electrical discharges in a primordial soup of water, methane, ammonia, and hydrogen create a slew of amino acids, that were capable of forming the basis for life. There is a long way from here to life, but this step was a big one.
You can regard the electrical discharges as being the energy input into the system, getting it over the first entropy hump. That could reasonably be regarded as an initial impulse.
So chemistry itself is electromagnetic?
Of course. That’s why they’re called “electrons”.
Anyone else singing Dark Side of the Moon now?
:smack: So…murk is a collection of neutrons and protons that trigger within?to…bridge?..and create life?
Might as well ask another basic question: what is the definition of life?
That’s a much more complicated question than you think. The best I can do is to say that life is something that meets all of the following criteria:
It takes in material from its environment.
It reproduces.
Its offspring have traits which can vary but which are inherited from its parent.
It has internal chemical reactions.
Sometimes you also see other criteria like “it excretes”, or “it is made up of cells”, but I don’t think either of those is necessarily true: One could imagine, for instance, an organism which just accumulates all of its waste inside of it until it dies. And all known life is made up of cells, but that wouldn’t be useful for judging alien life, since “cells” are mostly just defined as “the pieces that living things are made of”, and aliens will certainly be made up of pieces of some sort, but those pieces might not bear any particular resemblance to our cells.
I appreciate the replies. It’s a lot to mull over.
Speaking of not speaking of cells, I saw recently where life had been found to exist outside of cells…? Can’t remember what or where.
Yes, in the sense that chemical bonds are manifestations of the electromagnetic force, and depend on the arrangements of electrons around atoms and within molecules.
I am not sure what this word “murk” has to do with anything. You seem to think it is significant, but is not a scientific term, and not of obvious relevance to the origins of life.
Neutrons and protons make up the nuclei of atoms, but when we are talking about the origins of life we are talking about a situation in which the atoms, the chemical elements, are already formed and present. In this situation, neutrons and protons are not doing anything very much, the action is among the electrons that form the outer parts of the atoms, and which are involved in the creation (or breaking) of the chemical bonds through which atoms bind together to form molecules. Life depends on the formation of certain sorts of very large, complex molecules. Both the origin of life and the state of being alive are essentially highly complex chemical processes.
Unless you are talking about viruses, no life is known to exist outside of cells, and it is questionable whether viruses should count as being alive. In any case, they need to get into cells, the cells of some other, unquestionably living organism in order to reproduce.
You’re remembering wrong. Such a discovery would be a massive revolution and the biggest science news since the phrase “double helix” entered common usage.
Nitpick: There are some viruses known which infect other viruses. Which, in turn, must still invade unambiguously-living cells, but there are still viruses which don’t attack cells directly.
That is entirely consistent with what I said, though.
Very much an IMHO view here.
You get into all sorts of interesting issues. Clearly the sub-atomic particles are not alive, nor are the atoms, nor the amino acids and other molecules they may be components of. Similarly a strand of DNA isn’t alive all by itself, even if it codes for most of a living organism. Over your lifetime you will turn over a large fraction of your body, and only a fraction of the atoms you were made of a decade ago will still be present now, but you are still you, and still alive.
Some cells inside you border on not all that alive. Red blood cells have no nucleus, cannot reproduce, and lack a lot of the complex machinery of other cells.
There is a field of research into artificial life - which is mostly concerned with computer programs and algorithms that behave in lifelike ways. Here the manner in which complex self organising behaviour arises from perhaps simpler components is one of the rather interesting results.
Being a computer geek at heart, I tend to view all these things as sharing a commonality in information and self organisation plus an ability to reproduce. The linking idea being entropy. Looking at energy is a proxy for the entropy in physical systems, but it isn’t the movement of energy itself that matters, but the local change in entropy that the energy enables. That gives us a handle on the organisation of the components. The ability of the components to self organise and reproduce gets us to life.
You may be remembering this recent news about metabolitic reactions occuring without cells. I doubt it would it would fit anyones definition of life, but it’s another piece for the puzzle of how life might have arisen.
See [THREAD=299054]Why can’t my hand go through my desk?[/THREAD] for an in depth discussion on this.
All known life is fundamentally cellular in nature. Some cells (most prokaryotes) are open internally; that is, they don’t have a separate nucleus with genetic material and distinct organelles, but all are contained inside of a cellular membrane. There may be self-replicating or catalyzing precursors to life that were not cellular in nature, but all life as we recognize it is cellular in form.
Talk of viruses is a red herring. There is no question about whether viruses are alive or not; they cannot independently reproduce or self-repair without hijacking the mechanism of living cells, and therefore are not alive by any functional definition.
As for the actual mechanism which begat life, we cannot say. Certainly amino acids can be formed with energy provided by static discharge in a reducing atmosphere rich in organic compounds, as demonstrated in the Urey-Miller experiment, but this doesn’t mean that it is the only or even most likely path. We do know that energy input is required, and fundamentally life is a non-equilibrium thermodynamic (NET) system which moderates the flow of energy and uses that energy to self-organize, but the input energy could be in any form (electrical, chemical potential, thermal, et cetera) as long as it exceeds some critical threshold to keep the system working. But any discussion about what actually created life is necessarily speculative.
Stranger
I think the shortest definition of life that’s at all useful is “that which evolves itself.” Of course, that definition leaves a lot to the imagination, and it’s pretty much equivalent to Chrono’s list, but more abstract and a bit more applicable to “life” inside a computer (which is also arguably not “life” in some ways). Also, it might include other things many don’t consider “life”, such as molecular evolution (a likely precursor to life).
I disagree on several counts, while agreeing that a virus, by itself, is not a good example of “life”.
It’s not a red herring because it’s an excellent example of something that’s very much part of what we call “life” and definitely biological, but not quite what we’d call “life” in terms of being an organism. It’s right on the hazy edge of “life” and is very useful for discussions for that very reason.
Regarding the cellular nature of life. Of course, yes, life is described that way because it’s a characteristic of life as we know it. Furthermore, there’s a theoretical argument that life needs to have an “inside” and an “outside” – something that separates it from its environment. But I suspect it’s possible to find something most of us would call “life” without an actual physical membrane dividing the living stuff from its environment.
Back to the original question: spark versus murk. As mentioned above, we only have hazy theories about the origins of life. There are two or three major camps regarding how it might have started, and each camp has excellent arguments that imply that the other camp(s) can’t possibly be correct. (The original camps were “protein first” and “RNA first”, but now there are more subtly divided camps. However, I’m pretty sure that no camp is free from excellent arguments against it, unless things have changed radically in the last couple years.)
Before even these two camps were well established, there was the idea of a “primordial soup” that may have been “excited” into life precursors by lightning, and this might be where you’re getting the “spark” idea. There was a classic Miller-Urey experiment where scientists took the kinds of chemicals thought to be in the Earth’s early environment and zapped them, and lo and behold! Amino acids! (which are the components of proteins).
While it’s interesting and illuminating, there are a number of fallacies in assuming that “Bingo! Amino acids!” is equivalent to “Bingo! Life!” and those issues have been discussed nearly to death in the intervening 60 years (and also issues over whether the experiment posited a possible environment for early Earth). However, the experiment and similar ones produced more amino acids than are actually used by life (though I don’t know if all 20 used by life were found.) Similar experiments using volcanos rather than lightning produced similar results.
But the bottom line is that the zap wasn’t what gave the life its energy. It simply stirred the pot, chemically speaking, to produce some of the kinds of chemicals that are crucial to life (the chemicals that make up proteins, which are the “machinery” of life, but not the blueprints for the machinery.)
We’re a long, long way from having a good handle on how abiogenesis actually happened. The most remarkable thing is that, once Earth cooled down to a dull roar, it didn’t take long for it to happen, according to the best evidence, which puts the oldest life happening only 500 million years after the Earth formed.
Scanning the Wikipedia abiogenesis page, I see that it lists nearly a dozen different hypotheses. So far, there isn’t any consensus among scientists to suggest one of them is best.
Viruses are not ‘alive’ by and functional definition of life. That they interact with other proteins and can alter the functioning of cells is not in question, but the inability to self-replicate and self-repair (due to the lack of any kind of functioning metabolism or energy storage mechanism) makes them fundamentally non-living. They are best viewed functionally as a really complex, multifunctional enzyme.
Every single organism–that is, everything that has an intrinsic ability to regulate energy usage and storage via internal mechanisms, and use that energy to maintain and reproduce itself, is cellular in nature. And while we only have data from our single terrestrial cohort, there are some pretty good arguments for why any form of life, regardless of the substrate or information coding mechanism, is almost certain to be cellular in nature. The complex systems which form life are built from very similar, limited individual functions, which themselves arise from a handful of simple amino acids and a long chain information-storing molecule, which are all produced from a few relatively abundant family of atoms. In order to give rise to a functional complex system with sufficient flexibility to evolve in arbitrary fashion, a cellular organization is almost certainly necessary.
Stranger