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This past February, I took part in a meeting at CERN to discuss and debate the origin of life. Organized by Gnter von Kiedrowski and Eors Szathmary, it is possible that much may come of it. But first, let's start with a little of the history that led up to this moment.

Until Louis Pasteur, there was no origin of life problem: maggots just sprang spontaneously from dank wood after every rain. Pasteur showed us that life only comes from life. But where did life come from in the first place?

The problem rested until the early 20th century, when the concept emerged that a "primitive soup" of organic molecules had given birth to life.

The field leapt forward in the famous experiments of Stanley Miller. He showed that a retort filled with the gases presumed to have been present in the primitive Earth's atmosphere could produce amino acids, the building blocks of proteins, when stimulated by electric sparks that mimicked lightning. For some 40 years since, work along these lines has repeatedly demonstrated the prebiotic synthesis of many of life's organic molecules.

Following the discovery of the famous double-helix structure of DNA, and its cousin RNA, many researchers — Leslie Orgel, among them — adopted the view that molecular reproduction must be based on what is called "template replication" of single-stranded RNA polymers (polymers are made of many linked nucleotide monomers), or its cousins.

Here the "Watson" single-stranded polymer of a Watson-Crick double-stranded RNA helix, was to line up the free building blocks of RNA, A, U, C, G, the nucleotides, each lined up by the Watson-strand polymer, say AAUUCCGG with free U, U, A, A, G, G, C, C "base paired" to the Watson template in proper order. Then, without an enzyme, these free nucleotides were to be linked together to create the second, Crick strand. Then the two strands were to melt apart, i.e., "unzip", creating two single-stranded RNA template sequences, and this replicative process was to iterate to create a growing population of Watson-and-Crick strands.

In roughly 60 years of work since, efforts to confirm template replication have persistently failed. But it may yet succeed.

The next, now dominant, origin-of-life theory is the "RNA world." It was discovered that, in addition to proteins that could act as enzymes and catalyze, or speed up, chemical reactions, RNA molecules called ribozymes could do so as well. Here was the dream: the same class of molecules that carry genetic information, e.g., messenger RNA, could catalyze reactions. Perhaps one class of molecules, RNA, could both perform template replication and carry genetic information.

The RNA world view has morphed in at least two ways. First people have tried to evolve a ribozyme that can function as an enzyme able to link the free nucleotides above together, a so called "ribozyme polymerase." This approach has seen a bit of success, but seems stalled.

13.7: Cosmos And Culture

An Eclectic Mix Of Giants Takes On The Origin Of Life

If you're old enough to remember the movie The Blob, starring a gelatinous, oozing menace that gooped its way across floors, slid under doors, attached itself to an exposed foot, hand, arm and then devoured its screaming victim without making even a swallowing sound ... If you liked The Blob, then feast your eyes on this: Joey Shanks' Killer Silly Putty ... It's real — and it eats magnets! (You don't have to watch the whole thing to get the idea ...)

On poet Gwendolyn Brooks and how she recorded Chicago's vibrancy

"She's a really interesting case because she also overlaps with Mies in a very particular way: She, as a young woman, worked in this huge apartment building on, I want to say, 31st Street, 34th Street, called The Mecca, which became famous. There were blues songs written about it. And at The Mecca, Gwendolyn Brooks really got her sense of what this new Chicago was going to be like, the new black Chicago in Bronzeville. And at the same time, this is also part of where the Armour Institute, [Illinois Institute of Technology] campus is going to be. Mies ends up in 1955 building his great masterpiece crown hall on the site of The Mecca. So you have this overlap of these two great minds of Chicago talking about the same place in very, very different ways: Brooks from the bottom up and Mies very much from the top down, both masterpieces.

"Brooks was tapped into Chicago in a very special way in that she spoke so much about the domestic aspects of life. One of my favorite photos of her is her walking down 63rd Street with her kids in tow, groceries in her arms — no one notices who she is. She's a great poet of the domestic, and I think that's very true to the Chicago spirit."

On Chicago's street violence

"The most important point about those few streets in the middle of the city is that they belong to all of Chicago. And one of the impulses that one sees there is this discussion of Chicago and black Chicago. And in ... all that I've read, in interviews, there's often this discussion of two different cities. And I think when Chicago finally wraps its hands around all of itself and doesn't speak of it in these two different terms, I think they're going to be a lot closer to solving some of these problems."

Read an excerpt of The Third Coast

Kal Penn has a pretty unusual resume: He has starred in Harold and Kumar, the most successful series of stoner movies made in the past decade; and has served in the White House as the Obama administration's liaison to youth. Now he's hosting a new show, The Big Brain Theory, on the Discovery Channel.

We've invited him to play a game called "Ahhh! Get It Off Me!" You might be surprised to learn you're not alone in your body — there's a whole colony of bacteria and other critters called a "microbiome" living there. We're going to ask Penn three questions about our little unseen friends.