Simpler times: Did an earlier genetic molecule predate DNA and RNA?

[Tank]

Simpler times: Did an earlier genetic molecule predate DNA and RNA?

(PhysOrg.com) -- In the chemistry of the living world, a pair of nucleic acids—DNA and RNA—reign supreme. As carrier molecules of the genetic code, they provide all organisms with a mechanism for faithfully reproducing themselves as well as generating the myriad proteins vital to living systems.

Yet according to John Chaput, a researcher at the Center for Evolutionary Medicine and Informatics, at Arizona State University's Biodesign Institute®, it may not always have been so.

Chaput and other researchers studying the first tentative flickering of life on earth have investigated various alternatives to familiar genetic molecules. These chemical candidates are attractive to those seeking to unlock the still-elusive secret of how the first life began, as primitive molecular forms may have more readily emerged during the planet's prebiotic era.

One approach to identifying molecules that may have acted as genetic precursors to RNA and DNA is to examine other nucleic acids that differ slightly in their chemical composition, yet still possess critical properties of self-assembly and replication as well as the ability to fold into shapes useful for biological function.

According to Chaput, one interesting contender for the role of early genetic carrier is a molecule known as TNA, whose arrival on the primordial scene may have predated its more familiar kin. A nucleic acid similar in form to both DNA and RNA, TNA differs in the sugar component of its structure, using threose rather than deoxyribose (as in DNA) or ribose (as in RNA) to compose its backbone...

So TNA is posited as the precursor to RNA and DNA. Another simpler rung on the ladder leading from self assembling chemicals to self replicating molecules.

[Twentythree]

This is fascinating. Although I doubt we'll even know for sure, the exact chemistry and forces that existed on the early earth, I think science will get it pretty close. The great thing about this discovery is just another proof that in a lab non biological molecules can be found to be working in accordance with natural selection. I just can't see how there is any doubt persisting in the world about the way that selection works as a driving force in the universe.

[Crocoduck]

Ive been to a strip club named the T n' A 

[Tank]

Ive been to a strip club named the T n' A 

Now that doesn't shock me 

[xSilverPhinx]

Thanks for adding that, it's interesting