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.

Origin of Life and NSF

There are many interesting open scientific questions, but one of the most intriguing is how did life originate in the universe. This is the central question of astrobiology and this week three astronomers authored a commentary in Nature that argues, among other things, for NSF to “replace elements…of the Astronomy, Geophysics and Ecosystem Studies program…by one exoplanetary systems science program.” The lead author, Caleb Scharf is the director of astrobiology at Columbia University.

Origin of life biology goes far beyond the study of exoplanets, as the authors acknowledge. Fundamental questions in redox chemistry far from chemical equilibrium lead to the origins of metabolism, massively conserved across earth’s living forms. At the same time, the information flow from DNA to RNA and thence to proteins drives questions about the origin of the ribosome translation machinery. In 2015, while I was still heading up NSF BIO, we collaborated with NASA to fund an IDEAS lab to explore across these two threads (metabolism and RNA). These are two communities of thought that don’t often communicate.

But Scharf and his co-authors raise important points. There needs to be better cross-talk between astronomy, geosciences and life sciences if we are to make progress. I am not averse to supporting a reorganization of NSF programs in support of such trans disciplinary cross-pollination, but will just point out that it’s often easier to ignore bureaucratic boundaries than to redraw them.