The most recent issue of American Scientist (January-February 2006) had a very interesting article giving one theory about the origin of life on Earth. The author, Michael Russell, is a research fellow at the Scottish Universities Environmental Research Centre and currently a distinguished visiting scientist at JPL. His idea is that life orginated at warm (not hot) alkaline springs at the bottom of the early oceans. Here is the abstract:
Unfortunately, the article is only available on-line to members(link) or at your friendly neighborhood university library.

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Although his guess is probably more strongly scientificly based than mine as well as quite plausible, it's quite difficult to prove either of us wrong.

My guess is that the mixing dynamics of the CHON related elements that power carbon-in-water based life require that much of it happen in the protostellar cloud during the collapse that forms the star and eventually the planets. The opportunities for the atomic constituents of sugars and proteins to contact each other and mutually adhere will occur much more frequently in the nebula than at the bottom of some sizable body of water. The mutual affinities of these elements drive the forming of and preserve the molecular endurance of the molecules foundational to carbon-in-water based life and all the right stuff is sufficiently plentiful in this part of the MW. It's not too much of a stretch to expect that simple sturdy microbes self organized in the protostellar cloud and survived the crash onto Earth's surface through the methane enriched atmosphere.

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That theory's been around for several years, but it doesn't have any greater following than the shallow seas one. It's just so difficult to test anything so far back. Some folks are doing genetics tracer work to find "primordial sequences"; one day that may bear fruit.

What I feel is Russell's major contribution is not his theory per se, but the refined thought that went into it. Not like most people *like* microbial biochemistry, but it's very useful information to know.

I for one find the theory popularised by Russel quite plausible, it seems a logical place for life to have started? And its certainly one of the features of Earth that appears somewhat unique to this Solar System. But of course, without further empirical evidence its incredibly hard to prove conclusively.

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From Science News

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Heres yet another idea!http://discovermagazine.com/2008/feb...evolve-in-ice/

Seems like there are as many theories on the origins of life as there are... something else of which there is a lot of... I recently read somewhere (sorry, can't remember where) that life might have originated in the mildly radioactive sands/beaches of early Earth - the radioactivity providing the energy for life's jump-start.

And the answer might be that they are all right, at least to some extent. Organic compounds might have been made in ice, in hydrothermal vents, in radioactive sand, in the primoridial atmosphere, delivered by comets, etc. For example, complex carbohydrates might have come via one path, amino acids by another. Then somehow this complex mix came together and made.. us (or at least our ancestors). I think how this last step happened may be the hardest to answer.

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At night the stars put on a show for free (Carole King)

Looking at some of the fossils from ancient by gone eras... Some of those little guys were awfully weird...

I can't say I would be particularly surprised to learn that Several different beginnings took place. That life with a different form of DNA even formed here on Earth- but died out back then.

The problem with this theory is that back then the continents were very large which meant that the deep ocean would become anoxic. Unlike now with steep continental slopes and high land mass profiles, the continents were low and crossed by broad but very shallow epieric seaways. These seaways had extensive low energy, warm waters. By the Ordovician these were the the site of immense reefs that are source of much of the worlds oil. Stromatalites are a primitive form of life like an algal blanket that lives in shallow sandy lagoons, an environment something like an epieric seaway. This is where life could well have started.

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plenty of woo, at the hotel hoagaland...

So why are there no experiments with all these likely scenarios which produce Life from nonLife?

If scientists have determined the most likely conditions why has nothing more than organic goo been created in a lab?

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The impression I get from so many competing theories and no-one making artificial crittersis that any claim to 'most likely' conditions is iffy at best. The thing we are probably missing is the chance to explore all of the billions of possible pathways from none life to life over thousands to millions of years the way the young earth could.

We don't know if these are the "most likely" conditions or only "somewhat likely" conditions. We also know very little of the details of what the actual conditions were, and we haven't had millions of years to test variables on a planetwide or more scale as Moms Nature did.

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