Gotta check the article. RNA is Ribonucleic Acid right?
However, though researchers have been able to show how RNAs component molecules, called ribonucleotides, could assemble into RNA, their many attempts to synthesize these ribonucleotides have failed. No matter how they combined the ingredients a sugar, a phosphate, and one of four different nitrogenous molecules, or nucleobases ribonucleotides just wouldnt form.
Sutherlands team took a different approach in what Harvard molecular biologist Jack Szostak called a synthetic tour de force in an accompanying commentary in Nature.
By changing the way we mix the ingredients together, we managed to make ribonucleotides, said Sutherland. The chemistry works very effectively from simple precursors, and the conditions required are not distinct from what one might imagine took place on the early Earth.
Like other would-be nucleotide synthesizers, Sutherlands team included phosphate in their mix, but rather than adding it to sugars and nucleobases, they started with an array of even simpler molecules that were probably also in Earths primordial ooze.
They mixed the molecules in water, heated the solution, then allowed it to evaporate, leaving behind a residue of hybrid, half-sugar, half-nucleobase molecules. To this residue they again added water, heated it, allowed it evaporate, and then irradiated it.
At each stage of the cycle, the resulting molecules were more complex. At the final stage, Sutherlands team added phosphate. Remarkably, it transformed into the ribonucleotide! said Sutherland.
According to Sutherland, these laboratory conditions resembled those of the life-originating warm little pond hypothesized by Charles Darwin if the pond evaporated, got heated, and then it rained and the sun shone.
That's kind of the problem. The RNA world theory isn't all that far fetched but the self replication of RNA isn't exactly known - at least from things solely in the primordial soup and no proteins or activation factors. There have been some recent studies into ribozymes that can self replicate each other.
He doesn't understand what the term structure means for RNA. He likely means types. Synthesis of those types isn't the problem. The whole point of the science trying to prove the RNA World hypothesis is to form a progression from the primordial soup to a autocatalytic RNA to life composed of only RNA. They are also concurrently working on the evolution of RNA to DNA for storage purposes with the remnants thought to be ribosomal RNA.
Maybe I don't understand this stuff enough (I don't), but what's preventing these ribonucleotides that exist today from doing this same process out in nature? Is it because the conditions of the earth are so dramatically different that we can't just drop some ribonucleotides out in a pond and observe how it develops?