Which Came First?

I have a question for the TEs. Which evolved first RNA or DNA?

Most experts believe RNA predates DNA. Check out the RNA world hypothesis.

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"There is evidence for evolution, gobs and gobs of it. It is not just speculation or a faith choice or an assumption or a religion. It is a productive framework for lots of biological research, and it has amazing explanatory power. There is no conspiracy to hide the truth about the failure of evolution. There has really been no failure of evolution as a scientific theory. It works, and it works well." -- creation scientist Dr. Todd Wood

Most likely it was RNA

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"The Bible does not lend any moral support to natural selection...Ergo, natural selection is not a process that human beings should support." - SkyWriting

RNA.

Is this a trick question?

Also, RNA would not have evolved, it would have formed first. Since RNA in and of itself is not alive... you get the idea.

Metherion

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I can't go back to yesterday - because I was a different person then.

If you don't know where you are going, any road will get you there.

One of the secrets of life is that all that is really worth the doing is what we do for others.

--Lewis Carroll, all three.

Point of order...RNA may have evolved without being alive. Evolution does not require life to occur, merely self replicating systems.

This is correct, and I may very well be mistaken.

I simply do not know enough about advanced organic chem to know if RNA can self-replicate outside a cell, or not, to determine further. But you have a very good point

However, if I remember correctly, in space and other areas without self-replicating systems, some of the bases from RNA and DNA have been found, which is why I said what I said

But space, earth, HUGE difference lol.

Metherion

__________________
I can't go back to yesterday - because I was a different person then.

If you don't know where you are going, any road will get you there.

One of the secrets of life is that all that is really worth the doing is what we do for others.

--Lewis Carroll, all three.

In the right conditions, RNA certainly can self replicate outside of a cell. However, in abiogenesis theory, it is important to remember that no one is suggesting RNA spontaneously appeared and started doing its thing. There is almost certainly a very, very long line of precursor self replicators before RNA, each of THEM evolved from a simpler one. More efficient self replicators evolved, which then outcompeted their precursors, until we have RNA< which gave way to DNA. Were it not for Virusses and DNA's cooption of RNA to do its work for it, I would hypothosise that RNA would likely have gone the way of other precursors by now and been outcompeted by its decendent, DNA.

There are several examples of non RNA or DNA self replicators, even some non organic ones. The ones it is easiest to find info on are prions, as they seem to have had the most research done. Its an interesting field.

Ribonucleic acid (RNA) is a biologically important type of molecule that consists of a long chain of nucleotide units. Each nucleotide consists of a nitrogenous base, a ribose sugar, and a phosphate. RNA is very similar to DNA, but differs in a few important structural details: in the cell, RNA is usually single-stranded, while DNA is usually double-stranded; RNA nucleotides contain ribose while DNA contains deoxyribose (a type of ribose that lacks one oxygen atom); and RNA has the base uracil rather than thymine that is present in DNA.

RNA is transcribed from DNA by enzymes called RNA polymerases and is generally further processed by other enzymes. RNA is central to the synthesis of proteins. Here, a type of RNA called messenger RNA carries information from DNA to structures called ribosomes. These ribosomes are made from proteins and ribosomal RNAs, which come together to form a molecular machine that can read messenger RNAs and translate the information they carry into proteins. There are many RNAs with other roles – in particular regulating which genes are expressed, but also as the genomes of most viruses.

The most popular speculation among origin of life researchers is that RNA preceded DNA. It is deeply speculative and based mainly on the fact that RNA can act as both an information template and as a catalyst. DNA and Protein (the other two pillars of life) only fill the role of one or the other. There are major critics of the RNA world ideas, see the writings of Robert Shapiro.

The problem with abiogenesis is that you need both necessity and chance, that is you need both deterministic chemical reactions and probabilistic resources to come up with a solution. We are "light years" from a workable theory.