Sunday, October 19, 2008

Primordial Sludge

One of the enduring imaginative musings of my childhood is of a bolt of lightning striking a shallow pool of water. More like an indention in a rock, really, with a bit of rainwater barely deep enough to keep the mini-pond wet. As the lightning hits, it vaporizes the water and voila! Primordial sludge forms. Fast forward a couple of months and actual creatures – microscopic but creatures nonetheless – are wriggling out of the somehow still wet spot on the rock. Oh. Must have been a spring supplying the water. And there must have been a bit of shade so the microscopic creatures didn’t fry in the noonday sun. And there must have been some source of nutrients. But what did I know at six? And despite my youngest child’s current confusion, I wasn’t actually there at the moment that lightning bolt hit.

So imagine my delight to see in Science this week that someone actually did an experiment to see what would happen when lightning struck the presumed early building blocks of life on Earth. Yes. Back in the early 1950’s. Two chemists at the University of Chicago in Illinois, Miller and Urey, introduced an electric current to a mixture of gases and water in a closed loop of glass. When they analyzed the material that collected after a few hours, they discovered about 10 amino acids. BUT recent experiments on that same residue with an extremely sensitive mass spectrometer at NASA’s Goddard Space Flight Center in Greenbelt, MD revealed all 20 of the amino acids in things living today. Not bad. So now they’re wondering: 1) Could a volcano have started it all, and 2) How did this material – my fondly remembered primordial sludge – turn into “self-replicating organic compounds?” That’s the matter (no pun intended) now before geochemists Jim Cleaves and Jeffrey Bada.

I’m looking forward to seeing what they discover!

... Of course that still leaves the matter of the Creation of Adam on the ceiling of the Sistine Chapel. Forever linked in my mind with that lightning bolt and the sludge, there's no electric charge in evidence. But I've always been certain that Michelangelo has one implied. And that his imaginative musings were far more fully evolved than mine!

Source: http://sciencenow.sciencemag.org/cgi/content/full/2008/1016/1

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