nucleic acids less stable than thought, has implications for life's origin

[Odin2005]

http://www.sciencedaily.com/releases/2006/04/060408124233.htm

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The core of the debate, Kong said, relates to the behavior of the nucleic acid bases -- adenine, thymine, guanine and cytosine - that as A-T and G-C base pairs form DNA and ultimately become the blueprint for all living things. One of the most basic premises of biochemistry is that these nucleic acid bases are very stable, as they would have to be to prevent rampant mutations and make an organized genetic structure possible.

But studies at OSU, which were done with highly sophisticated electron spectroscopy, showed that the alleged stability of the nucleic acid bases in DNA is largely a myth.
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According to OSU research, the "dark state" essentially disappears in the presence of water. So if water were present, the earliest DNA bases would have been able to survive and eventually help form the basis for ever-more-complex life forms.

"In modern biological forms, it's not essential that water be present for DNA to have stability," Kong said. "There are other mechanisms that now exist in biology to accomplish that, and complex biological processes are possible that don't always require water. But in its most basic form, we now know that DNA bases are not stable and they are highly vulnerable to UV-induced damage."
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Looks like the tidal pool hypothesis for the origin of life is dead (pun intended). Deap ocean origin: 1, surface origin: 0.

[eppur_se_muova]

1. Actually, I believe one of the bases (adenine? IIRC) is constantly lost.

There are DNA enzymes which constantly keep repairing gaps where the adenine has fallen out. I believe adenine is also the one most prone to oxidation-induced damage.

DNA doesn't have to be *that* resistan to change to do its job well enough. This may be a straw man argument -- I don't know who's claimed that DNA is really all that robust in the absence of repair enzymes.