Evo Evo Evo, wherefore art thou?

Question

Ok here we go

primordial soup givers rise to amino acids, and protein chains and RNA

but hold on, you need RNA to make amino acids and protiens,
so how can amino acids make RNA, when RNA is needed to make them

ok i called this question EVo, When it's abiogenesis really but still, one supports the other as they suport the theory for millions of years...

but for millions of years how did we get amino acids if you need RNA to make them?

and we couldn't get RNA as we had no amino acids..for millions of years?

even if i added another million there we would still be in a period of activation as we lack the RNA and amino acids and therefore the RNA, yup you see where i am coming from

These are the problems you get when you study evolution and
abiogenesis,

i'm sure you must have the same problems too

your answers please

Answer 1

As you have correctly stated ... this is not an evolution question at all, but a question of abiogenesis.

This is an important distinction because evolution is an extremely well-developed theory, with enough empirical evidence for scientists to have arrived at a fairly universally agreed consensus about the main details.

The question of abiogenesis is far less further on in being solved. Unlike with evolution, there is not just one dominant and widely-accepted theory, but rather several, all quite plausible, candidates.

One of those theories, which addresses your question directly, is the 'RNA world' hypothesis (which is still called a hypothesis rather than a theory, because, while plausible that it *might* have occurred, there is still not strong evidence that it *did* occur).

This points out that RNA has some of the properties of proteins and DNA. Like proteins, RNA can act as a catalyst for reactions ... although not nearly as well as proteins can. And like DNA, RNA can hold inheritance information, although not nearly as robustly as DNA, which can grow *much* longer and still remain stable, and which therefore can hold the genetic information for much more complex organisms.

In short, RNA probably preceded proteins, as a self-replicating catalyst. The arrival of proteins as a more effective catalyst (although still encoded in RNA for inheritance purposes) came later. As did the arrival of DNA as a more stable inheritance medium. And that is why we have the DNA-RNA-protein trio we have today.

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P.S. Back to your comment about the relationship between evolution and abiogenesis ... yes they "support" each other, because they should not lead to contradiction ... but they do not *rely* on each other. For example, we could in fact discover that the earliest life forms were seeded from interstellar material, or were deliberately seeded by an intelligent being (like God, or some alien race) and this would not invalidate evolution (the development of that early life form into the species we see today) at all. The two theories are completely independent.

It's just like the question of the origins of the universe will need to be consistent with the laws of physics and chemistry we find today ... but that does not mean that the laws of physics and chemistry are invalid until we determine the origins of the universe! In exactly the same way, the theory of evolution is not dependent on the theory of the origins of life (abiogenesis).

Answer 2

It's not quite like you describe.

An important property of proteins is that they can be catalytic: they can increase the production of other substances (including proteins).
The important property of DNA is that it can store information.
RNA can actually do *both* - it stores information in the same was as DNA, but it can also be catalytic (these are called "ribozymes")

Additionally, RNA doesn't "make" amino acids; it uses pre-existing amino acids to assemble proteins.
And, in the "organic soup", amino acids can and will assemble to form short polypeptides: primitive proteins.

So the theory goes that you have an RNA strand that possesses the property of being autocatalytic (it can make copies of itself). the RNA does this and - because it is the only thing that can do this - you end up with lots of copies of this particular RNA molecule. This is HEREDITY and SELECTION.
However, this primitive RNA replication will not be very reliable: mistakes will be made. So you now have MUTATION.
Some of these different RNA molecules might be able to interact with the amino acids floating around. And if they can interact in a beneficial manner (such as also making proteins through ribozymic action, or stabilising the RNA structure, or ... well, lots of possible ways) then you have the beginnings of the RNA-to-protein synthetic pathway.

Check out the wikipedia entry on the "RNA World" for more information.

Answer 3

RNA can both hold information and catalyze reactions. RNA production theoretically does not require proteins. There are labs that have seeded RNA, then seen RNA grow into larger and larger strands.

However, no sort of life has come out of it, and the experimented required some predetermined conditions (like loading up on phosphates).

But yes this is an unresolved problem, but not disproven.

Answer 4

Ok, I don't know alot about abiogenesis, but it seems to me that if the evolution of the RNA molecule has occured over those millions of years, the process by which it is formed could also have undergone an 'evolutionary' transformation wherein the process has metamorphosized.

Just a thought.