Sludge In Flask Gives Clues To Origin of Life

sciencehabit writes "In the 1950s, scientist Stanley Miller conducted a series of experiments in which he zapped gas-filled flasks with electricity. The most famous of these, published in 1952, showed that such a process could give rise to amino acids, the building blocks of proteins. But a later experiment, conducted in 1958, sat on the shelf--never analyzed by Miller. Now, scientists have gone back and analyzed the sludge at the bottom of this flask and found even more amino acids than before--and better evidence that lightning and volcanic gasses may have helped create life on Earth."

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RNA World Hypothesis Says No

[Samantha Wright]

In the fifties, when these experiments was set in motion, it had just recently been proven that DNA was the mechanism by which cells passed on their programming to their offspring. Prior to that, the common belief was that proteins did all the work, and that DNA was just a structural fibre like cellulose. Today, we're strongly of the opinion that not only was protein less relevant to early life, but probably completely irrelevant, as we've determined that RNA can perform the role of both DNA (information storage) and proteins (enzymes and structure). Evidence suggests that it once performed both of these roles exclusively, and that DNA and proteins evolved because they were tools better-suited to certain tasks.

THEREFORE: the availability of amino acids isn't relevant to the origin of life; only that they're around later for higher life forms to evolve. We really need to worry about the availability of ribonucleotides. The idea that we need to worry about the availability of amino acids only comes later.

Re:No Repeats?

[Dahamma]

There are plenty of repeats of this - they just don't bother publishing them because there isn't much new to learn.

In fact, we repeated a version of the Urey-Miller experiment in my undergraduate biology lab independent project. The hard pard was going around bumming free equipment (high voltage transformer from the EE dept, balloons of elementary gases from the chemistry dept, even the help of a very cool tech in the physics dept who helped us make a simple spark gap chamber out of a glass bottle, a couple tungsten rods, and a blowtorch).

The goal was to repeat a few times with slightly different starting materials, and see what different amino acids we could find. Unfortunately, we managed to blow up the custom made spark bottle on the second run; someone dropped it and caused a hairline crack after the first run, and that let enough oxygen get in after we (not-so-successfully) evacuated it to cause a nice little explosion after turning on the spark gap. Luckily we were careful enough to put it under an enclosed fume hood ;)

In the end it was more an exersice in begging for supplies than novel science. But that was probably a lot more useful skill to learn for a budding researcher than how to inseminate a sea urchin...

Re:Who will all just plug their ears

[nedlohs]

That isn't what creationist means, in the context being used. It's short-hand for "young earth creationist, which is in turn short for "evolution didn't happen, God created everything in 6 days just like the bible says". Everyone knows that, well maybe you really are ignorant of context rather than just intentionally misinterpreting.

And there's only one rant in this thread, and it's not by anyone claiming religious types are wrong.

Re:Oh my...

[kubernet3s]

All right, all right, just hold your goddam horses. First of all, there are D and L amino acids. L, the ones which are "levorotary," or "left handed" are in fact the ones mostly used by eukaryotes, and the ones used as part of our metabolic pathways. However, many D acids are indeed useful to a variety of species, including many prokaryotes, the organisms believed to more greatly resemble the earliest life forms. Calling the product toxic is like calling oxygen caustic: accurate, but misleading. There are certainly more than a few organisms who might be quite happy mucking around in this stuff, which should be enough to push the intelligent biogenesis people in a slightly more sympathetic direction, if not the humans-and-dinosaurs-coexisted counterevolutionists.

Re:Who will all just plug their ears

[cbiltcliffe]

No. At least, not the knowledgeable ones.

They'll say something like:

"Stanley Miller's 1952 experiment has been shown to be flawed by more modern views of early Earth. The collection of gases that Miller filled his apparatus with before electrifying it was not characteristic of Earth's early atmosphere. Repeating the experiment with the proper gas mixture as generally accepted by current thinking shows no amino acid generation at all."

And then they'll say something about the right handed amino acids generated, which will destroy life, rather than create it, and the other toxic compounds created during the same experiment, that would have destroyed any chance of the left-handed amino acids forming life, if the acids hadn't been filtered out by the intelligent design of the experiment by the scientist.

And after that, they'll probably question the gases used for this 1958 experiment, assuming that the same mistakes made in 1952 would probably be repeated in 1958.

But then, I'm just guessing, and they may all say "NANANANANOTLISTENING" after all.

Re:Earth is BIG

[MaXintosh]

People need to Mod this up.

Creationists (and other ill minded ilk) seem to miss that this was the big revolution not just for abiogenesis. Suddenly organic compounds were in easy reach of inorganic reactions. This was really relevant for both biologists interested in the origin of life, but also people interested in organic chemistry basic research at the time. I was 'introduced' to this experiment twice in college - the first time was in biology, where you'd expect. But the second time was in organic chemistry.

Re:RNA World Hypothesis Says No

[drooling-dog]

We really need to worry about the availability of ribonucleotides.

Then you'll want to check out one of my favorite papers of the last several years (if you like organic chem):

Powner, M., Gerland, B., & Sutherland, J., Synthesis of activated pyrimidine ribonucleotides in prebiotically plausible conditions, Nature 459, 239-242 (2009).

These are activated (i.e., as the phosphates) ribonucleotides being synthesized in fairly high yields from a few simple molecules under mild conditions. It still blows my mind.