Origins of Life: RNA or DNA or both?

I have written about this scientific question before. How did DNA (more stable than RNA) come to be the primary information-store for living things?

Because we don’t have access to the early Earth, the question of how life arose on our planet remains obscure. But here is a new experimental result. The authors address the question of how RNA and DNA came to exist. These are of course the polymer molecules that store the information required to construct “Life”. The blueprint, if you will.

The elegant wet-lab experiments show how the letters of the RNA and DNA alphabet can be synthesized with the correct handedness (chirality for those with chemistry backgrounds) under conditions thought to exist on our Earth at the time that life originated.

The article is in Nature, so it’s behind their firewall. But the abstract is free to read.

Curiosity finds evidence for a habitable lake…on Mars

The report in SCIENCE is here. News story here. Short version: the Curiosity Mars Rover has found very strong evidence for a water-filled lake that lasted a minimum of thousands of years in Gale Crater (the landing site). Importantly, the lake’s PH (acidity) would have supported life. Even more exciting, there appears to be evidence for organic material–money quote from the news story:

When SAM heated the samples, the lakebed samples emitted more carbon dioxide than equal-size dust samples did, and their carbon dioxide came off at lower temperatures. Those observations suggested that heating the dust had simply decomposed naturally occurring, inorganic carbonate minerals, but that heating the lakebed samples had burned organic matter. Most telling, as carbon dioxide from the lakebed surged, the level of oxygen gas from decomposing perchlorates dropped. On seeing those data, one SAM team member reportedly declared, “This is combustion of organic carbon, folks.”

Fermi’s paradox revisited

Fermi’s paradox simply put is this:

If life is really ubiquitous throughout the Universe, how come we haven’t seen any evidence of our fellow biota yet?
Several of my colleagues are now finding increasing evidence that indeed, life is a natural emergent of the periodic table of the elements and therefore should be very common throughout this universe (assuming a potential multiverse scenario where our Universe is perhaps finely tuned).
If my colleagues are correct though, then this implies first, that life would be ubiquitous (given the sheer size of the Universe) but also, quite interestingly, showing no evidence at all of the technological “break out” that our own species has managed to achieve over the last several hundred years.
There are no SETI-radio signals as of yet (and it’s been several decades of searching)
Is life a natural emergent, but higher cognition much rarer?
If we look on the Earth itself, I find it intriguing that there are many big-brained species (Whales and Elephants come to mind) but only Homo sapiens have developed the technology to project evidence of themselves beyond the immediate planet (to say nothing of our solar system).