Scivillage.com Casual Discussion Science Forum

https://bigthink.com/hard-science/miller-urey/

INTRO: Science in the early 20th century was undergoing many simultaneous revolutions. Radiological dating numbered the years of Earth’s existence in the billions, and eons of sediment demonstrated its geological evolution. The biological theory of evolution had become accepted, but mysteries remained about its selection mechanism and the molecular biology of genetics. Remnants of life dated far, far back, beginning with simple organisms. These ideas came to a head with the question of abiogenesis: could the first life have sprung from non-living matter?

In 1952, a graduate student named Stanley Miller, just 22 years old, designed an experiment to test whether the amino acids that form proteins could be created under the conditions thought to exist on the primordial Earth. Working with his Nobel Prize-winning advisor Harold Urey, he performed the experiment, which is now told time and again in textbooks all over the world.

The experiment mixed water and simple gases — methane, ammonia, and hydrogen — and shocked them with artificial lightning within a sealed glass apparatus. Within days, a thick colored substance built up at the bottom of the apparatus. This detritus contained five of the basic molecules common to living creatures. Revising this experiment over the years, Miller claimed to find as many as 11 amino acids. Subsequent work varying the electrical spark, the gases, and the apparatus itself created another dozen or so. After Miller’s death in 2007, the remains of his original experiments were re-examined by his former student. There may have been as many as 20-25 amino acids created even in that primitive original experiment.

The Miller-Urey experiment is a daring example of testing a complex hypothesis. It is also a lesson in drawing more than the most cautious and limited conclusions from it.

Did anyone consider the glassware? In the years following the original work, several limitations curbed excitement over its result. The simple amino acids did not combine to form more complex proteins or anything resembling primitive life. Further, the exact composition of the young Earth did not match Miller’s conditions. And small details of the setup appear to have affected the results. A new study published last month in Scientific Reports investigates one of those nagging details. It finds that the precise composition of the apparatus housing the experiment is crucial to amino acid formation.

The highly alkaline chemical broth dissolves a small amount of the borosilicate glass reactor vessel used in the original and subsequent experiments. Dissolved bits of silica permeate the liquid, likely creating and catalyzing reactions. The eroded walls of the glass may also boost catalysis of various reactions. This increases total amino acid production and allows the formation of some chemicals which are not created when the experiment is repeated in an apparatus made of Teflon. But, running the experiment in a Teflon apparatus deliberately contaminated with borosilicate recovered some of the lost amino acid production... (MORE - details)

(Nov 21, 2021 06:04 PM)C C Wrote: [ -> ]In the years following the original work, several limitations curbed excitement over its result. The simple amino acids did not combine to form more complex proteins or anything resembling primitive life.

Yet people still try to cite stuff like this as evidence of abiogenesis. There is no evidence.

(Nov 21, 2021 10:59 PM)Syne Wrote: [ -> ]

(Nov 21, 2021 06:04 PM)C C Wrote: [ -> ]In the years following the original work, several limitations curbed excitement over its result. The simple amino acids did not combine to form more complex proteins or anything resembling primitive life.

Yet people still try to cite stuff like this as evidence of abiogenesis. There is no evidence.

Every time we eat, we perform abiogenesis. Inanimate matter is magically turned into animate matter, down to the molecular level.

(Nov 22, 2021 08:08 PM)Magical Realist Wrote: [ -> ]

(Nov 21, 2021 10:59 PM)Syne Wrote: [ -> ]Yet people still try to cite stuff like this as evidence of abiogenesis. There is no evidence.

Every time we eat, we perform abiogenesis. Inanimate matter is magically turned into animate matter, down to the molecular level.

No, you're just so scientifically ignorant that you conflate abiogenesis with energy conversion. Food is used as energy for life to grow, build new cells, heal, etc.. It's doesn't become life without a lifeform to convert it. Abiogenesis is life arising from non-living matter, not life continuing by using non-living fuel.

But thanks again for demonstrating your scientific illiteracy.

(Nov 22, 2021 08:08 PM)Magical Realist Wrote: [ -> ]

(Nov 21, 2021 10:59 PM)Syne Wrote: [ -> ]

(Nov 21, 2021 06:04 PM)C C Wrote: [ -> ]In the years following the original work, several limitations curbed excitement over its result. The simple amino acids did not combine to form more complex proteins or anything resembling primitive life.

Yet people still try to cite stuff like this as evidence of abiogenesis. There is no evidence.

Every time we eat, we perform abiogenesis. Inanimate matter is magically turned into animate matter, down to the molecular level.

If abiogenesis is plausible at all, I've thought it isn't a recurring process. If it were, wouldn't scientists be able to recreate it a controlled setting?

Quote:Food is used as energy for life to grow, build new cells, heal, etc..

Food isn't just energy for us. It provides the molecules themselves that structure cells. It provides proteins, sugars, water, minerals, fats, and vitamins that go to regenerating our flesh and bones. There is no distinction at this level between living and non-living. It is all one substance and structure. It is all organic chemistry.

(Nov 22, 2021 09:30 PM)Leigha Wrote: [ -> ]If abiogenesis is plausible at all, I've thought it isn't a recurring process. If it were, wouldn't scientists be able to recreate it a controlled setting?

It might be extremely rare and statistically require thousands or millions of years for unguided chemical processes to unfold and eventually produce a replicating molecule (or whatever primitive prototype); or the earliest and original environmental conditions are absent in this era and most previous ones; or the pervasive presence of existing microscope life swiftly eliminates or disrupts new occurrences, out-competes them, constantly consumes the potential for "primal chemical soup", etc.

In the context of laboratory experiments, the latter shouldn't be a concern, of course, if sterile equipment is the case.

There's panspermia, which includes the hypothesis that Mars might have had better replicator-inducive conditions in its distant beginning than Earth did (though "bio-friendliness" became quite the opposite _X_ years later). Panspermia subsumes both abiogenesis (happening somewhere else) and "unknown" ultimate provenances.

(Nov 22, 2021 09:35 PM)Magical Realist Wrote: [ -> ]

Quote:Food is used as energy for life to grow, build new cells, heal, etc..

Food isn't just energy for us. It provides the molecules themselves that structure cells. It provides proteins, sugars, water, minerals, fats, and vitamins that go to regenerating our flesh and bones. There is no distinction at this level between living and non-living. It is all one substance and structure. It is all organic chemistry.

No, now you're just demonstrating your ignorance of simple biology. Cells do not directly incorporate external molecules. They break apart molecules, releasing their binding electrons, which they then store as energy, by converting them into new molecules, like ATP.

Educate yourself, if you can even be bothered to learn any actual science: https://www.nature.com/scitable/topicpag...-14024533/

(Nov 22, 2021 10:03 PM)C C Wrote: [ -> ]Panspermia subsumes both abiogenesis (happening somewhere else) and "unknown" ultimate provenances.

Or just a run-of-the-mill infinite regress.

(Nov 22, 2021 08:08 PM)Magical Realist Wrote: [ -> ]Every time we eat, we perform abiogenesis. Inanimate matter is magically turned into animate matter, down to the molecular level.

Obviously, in order for 6-year-old Timmy's body to grow into that of an adult, some matter from food incrementally becomes the constitution of additional cells. As well, Roberto's weight increasing from 180 pounds at age twenty to an obese 454 pounds at age 35.

But life is already in progress -- existing biological systems are extracting calcium (bones), iron (blood), carbon, and other nutrients/minerals for the tissue increases.

Whereas abiogenesis refers to the original incremental development/emergence of cells from inanimate substances, without an existing living framework to implement that. (Though prototype components were surely the case at some point along the stages, reciprocally supplying at least a minor "sky-hook" to the lower level to gradually complete the ultimate transition to primitive cell structure.)

However, minus using the more precise term "abiogenesis", the recruitment of ordinary matter into existing biological systems can certainly be referenced.

I would suggest that may be what the following writer was doing -- if not for, IMO, his instead seeming to project an "abiogenesis" kind of category on the described situations without actually stating it directly. (Since "life arising spontaneously from nonliving matter" is what he was originally addressing.) Was simply looking for a random example, but it happens to have that (???) curiosity floating over it...

Life constantly arises from “nonliving matter”
https://thelogicofscience.com/2018/03/13...ng-matter/

"Creationists often argue that scientists’ lack of knowledge about how the first cell arose is evidence that life could not have arisen “spontaneously from nonliving matter.” Namely, the fact that it isn’t actually true. Life arises spontaneously from “nonliving matter” all the time. Creationists simply frame the argument in a deceptive way that ignores the chemical nature of living organisms. Every time an organism reproduces, life is arising from nonliving matter. Now, creationists will, of course, object to that claim because that new life came from the reproduction of another living organism, but that is actually entirely irrelevant. As I will explain in detail, life itself is simply a product of highly complex chemistry, and the process of reproduction consists entirely of chemical reactions among nonliving atoms. The living organism simply provides the environment in which that chemistry can take place."

All chemical reactions proceed at a rate determined by their probability. I'm fairly sure catalysts don't actually make an impossible reaction possible but they can drastically change the probability of it occurring. The result is that methane, ammonia, and hydrogen might take much longer to make a goo without the borosilicate test tube but it will still happen though possibly not at a rate that works as a school lab project. It would be surprising if volcanos didn't make borosilicate glass along with other silicate glasses so nature could easily supply the same ingredients as the controversial test tube.