Please help me understand as my brain has burst about this!

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UKJoy

Registered Member
Hello. Please have patience with me, because although I love the sciences, as I find virtually all of it fascinating, I am not a scientist and just a layperson, so please forgive my unscientific terminology. Thank you.

I've been reading about the machines that make DNA, RNA and protein, and I think I just about understand the stages involved, though that's about all so far as the way it all happens is too mind-blowing for me to get my head around just yet.

My main question that I can't get over in my head, is if all the machines are made from protein and RNA (in a human cell for example) and all those machines are needed to produce protein anyway; then in the very beginning of life evolving on Earth how could those machines be there without protein and how could protein be there without those machines? 'Chicken and egg' conundrum!

I have tried to find a valid explanation, but in layperson terms I'm not finding anything reasonable, though I'm sure there must be something in scientific papers, so I'm hoping someone here with that level of intelligence could please 'translate' the science for an ordinary person to understand.

I've read the theories about abiogenesis and Clay Theory, and meterors carrying proteins, random chance, etc, but even I can challenge those with my basic knowledge, so they don't satisfy me as being solid answers - like; surely the heat involved in a meteor strike would have destroyed any protein on it?

I have read about the ribosome having similarities to certain forms of bacteria, and that really interests me; so if anyone has theories about the start of life related to that idea I'd be very interested to read that answer. Thank you very much.
 
UKJoy said:
My main question that I can't get over in my head, is if all the machines are made from protein and RNA (in a human cell for example) and all those machines are needed to produce protein anyway; then in the very beginning of life evolving on Earth how could those machines be there without protein and how could protein be there without those machines? 'Chicken and egg' conundrum!
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This conundrum isn't just a biology issue, the same is often applied in Cosmology to "Where did the universe come from?", in the sense of if you start with nothing, then there is nothing to evolve and nothing in the future to attempt to insert something back to generate a paradox;
however if a paradox was to occur you'd end up with something in the space where nothing would have been and therefore no longer have to send something back to fill the void. (Classic quod erat demonstrandum)

Obviously nobody can give you a definitive answer, all you are going to get is a whole bunch of theories and you are really just going to have to pick one to "Believe" although there will always be attempts to test which theory can be scrutinised the furthest.

Personally I would go with a fuzzy and rather fruity notion that exist between a paradoxical seeding method (Protein sent back in time, or a time traveller peeing in the soon to be protozoic pool, as after all if you time travel you'd certain get to "piss on everyone")and the other personal favourite that we all just exist inside a super-composite emulator that is recursively intrinsic, where each universe aids in emulating a component of the overall composite and that an underlining sourcecode singularity could allow complete manipulation of the universe from our level. (Kind of "The Root-kit to the Universe" which isn't in bookstore's yet) With the latter, anything is possible, Everything is permitted.
 
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UKJoy said:
My main question that I can't get over in my head, is if all the machines are made from protein and RNA (in a human cell for example) and all those machines are needed to produce protein anyway; then in the very beginning of life evolving on Earth how could those machines be there without protein and how could protein be there without those machines? 'Chicken and egg' conundrum!
Click to expand...
You are being confused by the time-reference of these statements. All proteins now in existence are formed from other proteins. This does not imply that all proteins that ever existed were formed this way.

We have considerable understanding of biology as it currently exists on this planet, because there is a surfeit of empirical evidence.

There is less evidence of past life since organic tissue is fragile and does not last very long; all we have are fossils, in the oldest of which all the organic material has been replaced by minerals. Nonetheless, from this meager source we have still managed to figure out quite a bit about life in the past: the origin of the first mammals, the first vertebrates, the first angiosperms (flowering plants), etc. We've gone all the way back to some of the most primitive early animals.

Beyond that it becomes considerably more difficult. There are no fossils of the earliest organisms because they were too small, too fragile, and too many natural forces have wrought their destruction. We can only hypothesize their biology from the myriad forms of their descendants: the six kingdoms of animals, plants, algae, fungi, bacteria, and a poorly understood category of extremely primitive organisms we call archaea, which may actually comprise multiple kingdoms.

To go even beyond that, to the time when the first proteins were formed from inorganic compounds, is quite a challenge. It's very unlikely that we will ever find physical evidence left over from the process. We will probably have to simply duplicate it in the laboratory. I will probably not live to see this, but if you're as young as the average member of SciForums, you may very well see it yourself, or at least see so many bits of it come together that it will lose most of its mystery for you.

Good luck!
 
Mod note: Uneducated references to creators and design, and associated replies, have been moved to an appropriate thread.

Now....

UKJoy said:
then in the very beginning of life evolving on Earth how could those machines be there without protein and how could protein be there without those machines? 'Chicken and egg' conundrum!
Click to expand...

The prevailing paradigm for the pre-biotic era is the “RNA World” hypothesis. This proposes that the precursors to life were catalytic RNA molecules that could catalyse their own chemical synthesis. No protein enzymes required. Over time these RNA molecules changed to encode proteins. (NB. Protein translation from RNA does not require a cell; it proceeds in vitro if the required components are present.) Over further time these catalytic RNAs and early basic proteins became encased in lipid micelles, and there you have a proto-cell.

I’ve dumbed this down considerably because (a) it’s a very complex biochemical field, and (b) it’s not my field and I cannot expand on it if I wanted to. But hopefully you can see that there isn’t a ‘chicken and the egg’ conundrum with abiogenesis.


UKJoy said:
I have tried to find a valid explanation, but in layperson terms I'm not finding anything reasonable,
Click to expand...

Define “reasonable”. :confused: Where have you been looking?


UKJoy said:
though I'm sure there must be something in scientific papers, so I'm hoping someone here with that level of intelligence could please 'translate' the science for an ordinary person to understand.
Click to expand...

There certainly are many peer-reviewed papers on the subject. Unfortunately I don’t have the time to do this for you, much as I would like to.


UKJoy said:
I've read the theories about abiogenesis and Clay Theory, and meterors carrying proteins, random chance, etc, but even I can challenge those with my basic knowledge,....
Click to expand...

With respect, I doubt you can challenge professional research scientists and their professional research on the biochemical mechanisms of abiogenesis. Some very clever, educated and knowledgeable people work in the field and devise frameworks like the ‘clay theory’. On what basis do you think you can challenge their work? I’m not trying to be elitist, but the fact is layman’s intuition is rarely a good tool for evaluating complex scientific research.


UKJoy said:
....so they don't satisfy me as being solid answers - like; surely the heat involved in a meteor strike would have destroyed any protein on it?
Click to expand...

There are some very thermostable proteins. Besides, you’re mixing ideas. Abiogenic processes that turned inanimate matter into animate matter don’t require input from meters, meteorites or comets. Having said that, there are a number of hypotheses that suggest these extraterrestrial bodies seeded the Earth with raw materials, such as amino acids (as opposed to whole proteins) and simple carbohydrate monomers. Protein monomers (amino acids) and carbohydrate monomers are much more thermostable than the polymers they contribute to.


UKJoy said:
I have read about the ribosome having similarities to certain forms of bacteria, and that really interests me; so if anyone has theories about the start of life related to that idea I'd be very interested to read that answer.
Click to expand...

Ribosomes are comprised of proteins and RNA. So, in some respects, they may indeed reflect an early proto-cell. I don’t know anything more on this, however.
 
Hercules Rockefeller

To Hercules Rockefeller...

Hi. Thanks for doing your best to "dumb it down" for me; though I really don't appreciate the condescending tone of your language one little bit - it expresses a wholely unnecessary attitude of superiority, even though you do admit a few times that you're no expert in this field anyway.

From what I've read about the theory of the RNA world it's a purely speculative hypothesis that cannot be proven nor upheld by any credible evidence; therefore placing all one's faith in this does seem illogical to me.

FYI... I'm not a scientist, but I'm not an idiot either.

Thanks.
:rolleyes:
 
UKJoy said:
. . . . placing all one's faith in this does seem illogical to me.
Click to expand...
Hardly illogical. Being supportive of research into a promising hypothesis isn't the same as treating it as though it has been verified.

There is a huge difference between rational faith and irrational faith. The former is based on at least a modicum of evidence, such as consistency with proven theories. The latter is based on a hunch, the authority of someone with no credentials, or sheer wishful thinking.
 
UKJoy said:
I really don't appreciate the condescending tone of your language one little bit
Click to expand...

If you think that was condescending then you are reading too much into it, as well as overreacting. I’m merely prompting you to justify your position.


UKJoy said:
From what I've read about the theory of the RNA world it's a purely speculative hypothesis that cannot be proven nor upheld by any credible evidence; therefore placing all one's faith in this does seem illogical to me.
Click to expand...

No one’s placing “faith” in anything. That’s not how the scientific method works. We don’t know how life first arose on this planet, so we look at the evidence (geological, meteorological, planetary) and perform biochemical and geochemical experiments then devise hypotheses based on those observations and experimental data. Our knowledge of abiogenic processes is not, and will never be, as detailed as it is for extant life for obvious reasons. But science goes with the best naturalistic explanations it can generate from available data. No one is harder on scientists than other scientists. You can rest assured that these hypotheses are continually challenged. If you have a better explanation, then tell us – there are whole scientific conferences devoted to this subject.

And you didn’t answer my questions. How do you define “reasonable evidence” (from your previous post) and “credible evidence” (from this post)? What sort of evidence do you require for it to be reasonable and credible? Who says there is no credible evidence? You? An expert in biochemistry? What material have you read that says there is no credible evidence?


UKJoy said:
FYI... I'm not a scientist, but I'm not an idiot either.
Click to expand...

Fine. But you had best stop rolling your eyes as I think you’ll only succeed in embarrassing yourself. You’ve stressed that you are a layman and not a scientist, yet here you are making pronouncements of illogicality with respect to the science of abiogenesis. I have a background in genetics and cell biology; research in these areas is my career, yet I would not presume to judge the work of scientists in the field of pre-biotic chemistry as I don’t know enough about it. How can you? "...but even I can challenge those with my basic knowledge", you said.
 
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