Primordial Soup: Interview with Stanley Miller

An anonymous reader writes "Stanley Miller's classic 'primordial soup' experiments showed that 13 of the 21 amino acids necessary for life could be made in a glass flask. For its fifty-year commemoration, Miller is interviewed today and reflects on what Carl Sagan called 'the single most significant step in convincing many scientists that life is likely to be abundant in the cosmos.'"

Comments

I tried this experiment in high school...sort of

[Saint Aardvark]

I tried duplicating Miller's experiment in my last year of high school for my chemistry final project. I didn't have a way of zapping the gases, so I tried shining a UV lamp on them; I'd read about different versions of the experiment that had tried that with success. And I didn't have a way of evaporating and condensing the liquids, so I just poured 'em into a big jar and hoped the interface between liquid and gas, combined with whatever UV light made it through the glass, would make amino acids. And I didn't have a gas chromatograph, so I had to use a chemical...damn, don't remember what it was, but it turned purple in the presence of amino acids and is used to detect fingerprints on paper.

It hardly needs saying, but in a week I didn't make any amino acids I could detect. Nevertheless, I ended up getting a shockingly high mark because I'd written up every possible reason I could think of for the experiment failing: not enough time, not enough interaction between liquid and gas, not enough energy from the light, test wasn't sensitive enough, Miller had faked his results (ha!), etc. I was disappointed in the results, but pretty happy with my mark. :-)

High School Biology Class

[Schezar]

For two years, I bugged my Biology teachers to let my try the Miller experiment with the school's equipment. (Of course, I was the same one who wanted them to let me make a gauss rifle, a betatron, and potato gun...)

I remember being fascinated when I first heard of the experiment. It seemed so 'important,' despite the fact that they brushed right over it and no one else in my classes understood or cared.

Of course, now I'm in college, and I can try all of these things with my own equipment.

Ah, but does he mention that his amino acids...

[leonbrooks]

...broke down as fast as they were made (in a carefully customised device, not in the wild), and were completely racemised at formation? Or that no evidence of a reducing atmosphere exists?

Just like every other fairy tale: exciting, adventurous, believable, and wrong.

Re:Carl Sagan was missing Billions and Billions of

[dubstop]

You're whining that the odds are too big, but it's guys like Stanley Miller that are trying to figure out exactly how big those odds are.

You might want to actually provide some facts as to why Carl Sagan was wrong, rather than make an ad hominem attack. Most truly academic scientists generally take a bit more convincing than just being told that, "The guy was an asshole, so he must be wrong."

Re:Carl Sagan was missing Billions and Billions of

[Planesdragon]

So, the chances are actually incalculable. Lottery = your chances in getting picked out the pool may be one in a million, but your chances of picking the right number on the right day and being that one in a million are impossible odds. Then you have the odds of actually claiming your prize and meeting the eligibility/legitimacy of the prize.

Odd. I could swear that there are people who've actually won the lottery... a couple hundred in America, I wager, which puts them at just about 1 in a million. ;)

Statistic impossibilities mean "don't plan on it happening to you," not "it'll never happen to anyone."

Re:I love this experiment

[davesag]

I personally take the position that it can be well shown that evolution is largely inconclusive.

ROTFLMAO

Evolution is one of the most established theories there is. Every test designed to disprove the theory has failed. The theory that living things evolve is just a theory, like the theory that gravity acts between two physical objects is only a theory. On the other hand the theory that an almighty creator created everything is so specious if defied reason. It's not testable, it's not falsable, it's not scientific. It's the work of cranks and crazies from thousands of years ago who had nothing else to explain what they could see. The point of science is that all theories should be debunked, and debunkable. Theories that withstand efforts to debunk them are good theories, but still only theories. Theories that make predictions when are then verified by experiment are good theories.

And this talk of 'god guided evolution' is also just a crock. I mean if your god is so amazing then why does he need to guide evolution? for sport? he's omniscient and beyond such earthly pleasures surely.

no. if you overuse mouthwash the plaque causing bacteria will evolve to eat that mouthwash. if you take antibiotics the bacteria aflicting you will evolve resistance via the very well understood mechanisms of natural selection. the list of examples that support evolutionary theories is inexhaustable. why posit the existance of a god when it's just not needed to explain things and does not add in any way to our understanding of the world.

evolution even works in software. genetic programming, genetic algorithms, evolutionary computing - does god guide these?

you can even look at evolution in non-living systems. take for example the vinyl LP. faced with 'attack' by CDs and CD players, the LP and turntables, evolved from a recording medium into a musical instrument in their own right. did god have a vested interest in the survival of LPs? is god a DJ?

Your god bats for both sides. the god the poor iraqi's were busy praying to is the same god as yours. Those guys who flew planes into the WTC - same god driving their bus too.

Miller is defunct

[searleb]

For more information on Miller and prebiotic Earth, here is a quotation from an Angew. Chem. review article by Kay Severin called Hot Stones or Cold Soup? New Investigations on the Endogenous Origin of Organic Compounds on Earth (Angew. Chem. Int. Ed 2000, 39, No. 20). It pretty much sums up the Miller reactions, why they're wrong, and what people think now:

"The most famous experiment ... was carried out almost fifty years ago by Stanley L. Miller, at that time a PhD student in the group of Harold Urey in Chicago. Miller was able to show that electric discharges in an atmosphere of methane, ammonia, hydrogen, and water led to the formation of significant amounts of various amino acids. Experiments of this kind were repeated in numerous variants. If reducing gases were employed mixtures of organic compounds of low molecular weight could be detected in many cases. This has led to the popular idea that the primordial ocean resembled a nutritious soup.

"But the possibility that earth once had a reducing atmosphere is questioned. A well known argument against it is the high photolability of methane and ammonia. Because a shielding layer of ozone was missing a high concentration of these gases is believed to be unlikely. Furthermore, several other results point to a neutral atmosphere of CO2 and N2. Given the fact that the atmosphere was based on an unproductive mixture of CO2 and N2 the nutritional value of the primordial ocean drops significantly.

"An alternative scenario has been propagated for several years by [Gunter] Wachterhauser. Instead of a primordial soup he favors hot minerals as the place where organic molecules were initially built as life subsequently emerged. Especially sulfur-containing minerals like pyrite are proposed to have acted as an energy source and catalyst both under the extreme conditions found in hydrothermal or volcanic vents."

Basically, primordial soup syntheses (like Miller's reactions) are out and hot rock syntheses are in. These hot rock procedures have much much much lower yields, but people are slowly figuring out how to build amino acids through them. For instance, people, headed by Wachterhauser, have figured out how to carbon fixate (condense) carbon monoxide and carbon dioxide into organic building blocks for amino acids. For instance, in early 2000, Chen and Bahnemann were able to convert CO2 and water to small organics (acetaldehyde, ethanol, acetic acid) at high pressures and temperatures. Similarly, people have figured out how to take amino acids and convert them into peptides under high temperature and pressure situations.

However, to date no one has been able to actually make an amino acid through these techniques. As a result, the proof that amino acids were delivered by comets or meteorites (true fact, this is not an x-file) and now space dust, becomes much more appealing. Once the building blocks arrived on Earth, these hot rock syntheses could have taken over.