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Re: How Life May Have First Emerged On Earth (Abiogenesis Thread)

Started by Icarus, December 13, 2014, 11:41:28 PM

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Randy

Quote from: xSilverPhinx on March 18, 2021, 02:19:36 PM
Quote from: Randy on March 18, 2021, 01:28:12 AM
For some reason that doesn't surprise me. I've always imagined that lightning would be the catalyst although I don't know why.

You're probably thinking about the Miller–Urey experiment? :notsure:
It could be I suppose. It's not ringing any bells for me.
"Maybe it's just a bunch of stuff that happens." -- Homer Simpson
"Some people focus on the destination. Atheists focus on the journey." -- Barry Goldberg

xSilverPhinx

Quote from: Randy on March 18, 2021, 07:02:08 PM
Quote from: xSilverPhinx on March 18, 2021, 02:19:36 PM
Quote from: Randy on March 18, 2021, 01:28:12 AM
For some reason that doesn't surprise me. I've always imagined that lightning would be the catalyst although I don't know why.

You're probably thinking about the Miller–Urey experiment? :notsure:
It could be I suppose. It's not ringing any bells for me.

I don't think there is a biology textbook that doesn't mention that experiment. :shrug:  :P
I am what survives if it's slain - Zack Hemsey


Tank

Quote from: xSilverPhinx on March 20, 2021, 01:02:53 AM
Quote from: Randy on March 18, 2021, 07:02:08 PM
Quote from: xSilverPhinx on March 18, 2021, 02:19:36 PM
Quote from: Randy on March 18, 2021, 01:28:12 AM
For some reason that doesn't surprise me. I've always imagined that lightning would be the catalyst although I don't know why.

You're probably thinking about the Miller–Urey experiment? :notsure:
It could be I suppose. It's not ringing any bells for me.

I don't think there is a biology textbook that doesn't mention that experiment. :shrug:  :P

I would suspect you're right. Except for creationist based biology text books that is :D
If religions were TV channels atheism is turning the TV off.
"Religion is a culture of faith; science is a culture of doubt." ― Richard P. Feynman
'It is said that your life flashes before your eyes just before you die. That is true, it's called Life.' - Terry Pratchett
Remember, your inability to grasp science is not a valid argument against it.

xSilverPhinx

Quote from: Tank on March 20, 2021, 11:18:55 AM
Quote from: xSilverPhinx on March 20, 2021, 01:02:53 AM
Quote from: Randy on March 18, 2021, 07:02:08 PM
Quote from: xSilverPhinx on March 18, 2021, 02:19:36 PM
Quote from: Randy on March 18, 2021, 01:28:12 AM
For some reason that doesn't surprise me. I've always imagined that lightning would be the catalyst although I don't know why.

You're probably thinking about the Miller–Urey experiment? :notsure:
It could be I suppose. It's not ringing any bells for me.

I don't think there is a biology textbook that doesn't mention that experiment. :shrug:  :P

I would suspect you're right. Except for creationist based biology text books that is :D

Those are toilet paper,  not biology textbooks.  ;)
I am what survives if it's slain - Zack Hemsey


No one

Toilet paper already covered in shit is by definition, useless...........oh, I see what you did there.

Recusant

Some Creationists are avid to discuss the Miller-Urey experiment as supposed evidence that abiogenesis is impossible. See for example the luminaries employed by Mr. Ham. A link to an archived page.

QuoteSome museums may discuss the Miller-Urey experiment of 1953 as evidence that abiogenesis can occur. Anti-evolutionist Philip Johnson informs us:

QuoteBecause post-Darwinian biology has been dominated by materialist dogma, the biologists have had to pretend that organisms are a lot simpler than they are. Life itself must be merely chemistry. Assemble the right chemicals, and life emerges. DNA must likewise be a product of chemistry alone. As an exhibit in the New Mexico Museum of Natural History puts it, "volcanic gases plus lightning equal DNA equals LIFE!" When queried about this fable, the museum spokesman acknowledged that it was simplified but said it was basically true. (Phillip Johnson, Weekly Wedge Update, April 30, 2001, p. 1.)

This experiment actually showed that abiogenesis cannot occur.

[Continues . . . of course.]
"Religion is fundamentally opposed to everything I hold in veneration — courage, clear thinking, honesty, fairness, and above all, love of the truth."
— H. L. Mencken


Randy

Quote from: Tank on March 20, 2021, 11:18:55 AM
Quote from: xSilverPhinx on March 20, 2021, 01:02:53 AM
Quote from: Randy on March 18, 2021, 07:02:08 PM
Quote from: xSilverPhinx on March 18, 2021, 02:19:36 PM
Quote from: Randy on March 18, 2021, 01:28:12 AM
For some reason that doesn't surprise me. I've always imagined that lightning would be the catalyst although I don't know why.

You're probably thinking about the Miller–Urey experiment? :notsure:
It could be I suppose. It's not ringing any bells for me.

I don't think there is a biology textbook that doesn't mention that experiment. :shrug:  :P

I would suspect you're right. Except for creationist based biology text books that is :D
Which is one line (easy to read), "Magic!"
"Maybe it's just a bunch of stuff that happens." -- Homer Simpson
"Some people focus on the destination. Atheists focus on the journey." -- Barry Goldberg

xSilverPhinx

Quote from: No one on March 20, 2021, 03:58:33 PM
Toilet paper already covered in shit is by definition, useless...........oh, I see what you did there.

Pretty much :grin:
I am what survives if it's slain - Zack Hemsey


xSilverPhinx

Quote from: Recusant on March 20, 2021, 07:31:17 PM
Some Creationists are avid to discuss the Miller-Urey experiment as supposed evidence that abiogenesis is impossible. See for example the luminaries employed by Mr. Ham. A link to an archived page.

QuoteSome museums may discuss the Miller-Urey experiment of 1953 as evidence that abiogenesis can occur. Anti-evolutionist Philip Johnson informs us:

QuoteBecause post-Darwinian biology has been dominated by materialist dogma, the biologists have had to pretend that organisms are a lot simpler than they are. Life itself must be merely chemistry. Assemble the right chemicals, and life emerges. DNA must likewise be a product of chemistry alone. As an exhibit in the New Mexico Museum of Natural History puts it, "volcanic gases plus lightning equal DNA equals LIFE!" When queried about this fable, the museum spokesman acknowledged that it was simplified but said it was basically true. (Phillip Johnson, Weekly Wedge Update, April 30, 2001, p. 1.)

This experiment actually showed that abiogenesis cannot occur.

[Continues . . . of course.]

Urgh, Ken Ham. I doubt he can tell the difference between a page from a good biology textbook and used toilet paper.
I am what survives if it's slain - Zack Hemsey


Recusant

Current research on the "water paradox" (water is necessary for the processes of life, but loss of water is necessary for the basic compounds of life to form). This paradox is beloved of Creationists, but of course they also find it necessary to misrepresent the facts ("Water Paradox: Water Needed for Cells Yet Water Destroys Living Things"). It seems to be a compulsion, which I suppose is understandable. The facts are not in their favor.

"Water was both essential and a barrier to early life on Earth – microdroplets are one potential solution to this paradox" | The Conversation

QuoteIt's a paradox: Life needs water to survive, but a world full of water can't generate the biomolecules that would have been essential for early life. Or so researchers thought.

Water is everywhere. Most of the human body is made of it, much of planet Earth is covered by it and humans can't survive more than a couple of days without drinking it. Water molecules have unique characteristics that allow them to dissolve and transport compounds through your body, provide structure to your cells and regulate your temperature. In fact, the basic chemical reactions that enable life as we know it require water, photosynthesis being one example.

However, when the first biomolecules like proteins and DNA started coming together in the early stages of planet Earth, water was actually a barrier to life.

The reason why is surprisingly simple: The presence of water prevents chemical compounds from losing water. Take, for example, proteins, which are one of the main classes of biological molecules that make up your body. Proteins are, in essence, chains of amino acids linked together by chemical bonds. These bonds are formed through a condensation reaction that results in the loss of a molecule of water. Essentially, the amino acids need to get "dry" in order to form a protein.

[. . .]

Over the years, researchers have proposed many solutions to this "water paradox." Most of them rely on very specific scenarios on early Earth that could have allowed water removal. These include drying puddles, mineral surfaces, hot springs and hydrothermal vents, among others. These solutions, while plausible, require particular geological and chemical conditions that might not have been commonplace.

In our recent study, my colleagues and I found a simpler and more general solution to the water paradox. Quite ironically, it might be water itself – or to be more precise, very small water droplets – that allowed early biomolecules to form.

[Continues . . .]
"Religion is fundamentally opposed to everything I hold in veneration — courage, clear thinking, honesty, fairness, and above all, love of the truth."
— H. L. Mencken


Recusant

This isn't panspermia really. Similar but more mundane. Therefore more plausible in my opinion.

"Crucial building blocks of life on Earth can more easily form in outer space – new research" | The Conversation

QuoteThe origin of life on Earth is still enigmatic, but we are slowly unravelling the steps involved and the necessary ingredients. Scientists believe life arose in a primordial soup of organic chemicals and biomolecules on the early Earth, eventually leading to actual organisms.

It's long been suspected that some of these ingredients may have been delivered from space. Now a new study, published in Science Advances, shows that a special group of molecules, known as peptides, can form more easily under the conditions of space than those found on Earth. That means they could have been delivered to the early Earth by meteorites or comets – and that life may be able to form elsewhere, too.

[. . .]

In their new study, the scientists look at the dense environment of dusty disks, from which a new solar system with a star and planets emerges eventually. Such disks form when clouds suddenly collapse under the force of gravity. In this environment, water molecules are much more prevalent – forming ice on the surface of any growing agglomerates of particles that could inhibit the reactions that form peptides.

By emulating the reactions likely to occur in the interstellar medium in the laboratory, the study shows that, although the formation of peptides is slightly diminished, it is not prevented. Instead, as rocks and dust combine to form larger bodies such as asteroids and comets, these bodies heat up and allow for liquids to form. This boosts peptide formation in these liquids, and there's a natural selection of further reactions resulting in even more complex organic molecules. These processes would have occurred during the formation of our own Solar System.

Many of the building blocks of life such as amino acids, lipids and sugars can form in the space environment. Many have been detected in meteorites.

Because peptide formation is more efficient in space than on Earth, and because they can accumulate in comets, their impacts on the early Earth might have delivered loads that boosted the steps towards the origin of life on Earth.

[Continues . . .]

The paper is open access and linked in the second paragraph above, and again:

"Formation of extraterrestrial peptides and their derivatives" | Science Advances

QuoteAbstract:

The formation of protein precursors, due to the condensation of atomic carbon under the low-temperature conditions of the molecular phases of the interstellar medium, opens alternative pathways for the origin of life.

We perform peptide synthesis under conditions prevailing in space and provide a comprehensive analytic characterization of its products. The application of 13C allowed us to confirm the suggested pathway of peptide formation that proceeds due to the polymerization of aminoketene molecules that are formed in the C + CO + NH3 reaction.

Here, we address the question of how the efficiency of peptide production is modified by the presence of water molecules. We demonstrate that although water slightly reduces the efficiency of polymerization of aminoketene, it does not prevent the formation of peptides.
"Religion is fundamentally opposed to everything I hold in veneration — courage, clear thinking, honesty, fairness, and above all, love of the truth."
— H. L. Mencken


Icarus

Not sure about believing a recent article by Neai DeGrasse Tyson.  He is telling us about an asteroid named Apophis. It is due to invade our space in 2027. It will come within 600 to 700 miles of our surface.  No sweat, it will miss us...........WHoa!!!!  Our earth gravity will alter the orbit of the asteroid as it passes through.. It will return within seven years and its' altered path will smash it into earth.

I reckon that if the Apophis collision occurs, our Pentecostals who yearn for the Rapture will then be delivered.

Dark Lightning

That distance of approach from the earth would likely be catastrophic in many ways. There are literally thousands of spacecraft in low earth orbit (fuck you, Elon, with astronomical observation interference from your swarm!) that would be affected, not to mention the spacecraft in high earth orbit. That thing needs a nudge.

Recusant

Still plugging away at understanding abiogenesis. The discovery described below isn't in any way conclusive, using as it does a sort of catalyst in the form of fragments of DNA to produce the result, but it's perhaps a significant step to understanding.

"Scientists Discover How Complex Molecules May Have Stabilized to Spark Life on Earth" | Science Alert

QuoteHighly reactive complex molecules finding some sort of stability was a necessary step towards life getting started on Earth. Scientists think they've just discovered how these first began to stay intact and spark the journey towards organisms.

We haven't been able to explain how the simple molecules that would've been floating around in the primordial waters of early Earth eventually latched on to each other long enough to form something as complex as RNA (ribonucleic acid).

So researchers in Germany created conditions to match ancient Earth in their laboratory. They focused on RNA-like units, synthetic chemical components capable of combining with each other in different combinations to create evolving strings of 'information', just like our own genetic material.

"We know which molecules existed on the early Earth," says chemist Job Boekhoven, from the Technical University of Munich. "The question is: can we use this to replicate the origins of life in the lab?"

When exposed to a 'fuel' of high-energy molecules, the synthesized RNA-like units joined up and broke down constantly in various configurations and scenarios. By themselves, they did not remain connected for very long.

What ultimately made the difference to molecule stabilization in the experiments was the introduction of additional short strands of preformed DNA (deoxyribonucleic acid) 'templates'. This enabled more complex molecules to form more often and also last longer, pairing up with the template to create more stable double-stranded molecules.

"The exciting part is that double strands lead to RNA folding, which can make the RNA catalytically active," says Boekhoven.

[Continues . . .]

The paper is open access:

"Template-based copying in chemically fuelled dynamic combinatorial libraries" | Nature Chemistry

QuoteAbstract:

One of science's greatest challenges is determining how life can spontaneously emerge from a mixture of molecules. A complicating factor is that life and its molecules are inherently unstable—RNA and proteins are prone to hydrolysis and denaturation. For the de novo synthesis of life or to better understand its emergence at its origin, selection mechanisms are needed for unstable molecules.

Here we present a chemically fuelled dynamic combinatorial library to model RNA oligomerization and deoligomerization and shine new light on selection and purification mechanisms under kinetic control. In the experiments, oligomers can only be sustained by continuous production. Hybridization is a powerful tool for selecting unstable molecules, offering feedback on oligomerization and deoligomerization rates.

Moreover, we find that templation can be used to purify libraries of oligomers. In addition, template-assisted formation of oligomers within coacervate-based protocells changes its compartment's physical properties, such as their ability to fuse. Such reciprocal coupling between oligomer production and physical properties is a key step towards synthetic life.
"Religion is fundamentally opposed to everything I hold in veneration — courage, clear thinking, honesty, fairness, and above all, love of the truth."
— H. L. Mencken


Tank

If religions were TV channels atheism is turning the TV off.
"Religion is a culture of faith; science is a culture of doubt." ― Richard P. Feynman
'It is said that your life flashes before your eyes just before you die. That is true, it's called Life.' - Terry Pratchett
Remember, your inability to grasp science is not a valid argument against it.