Here’s a fascinating new finding. Them scientists keep getting closer.
Process that might have led to first organic molecules
New research could have relevance to search for extraterrestrial life, green chemistry
Date: September 8, 2020
Source: American Museum of Natural History
Summary: New research identifies a process that might have been key in producing the first organic molecules on Earth about 4 billion years ago, before the origin of life. The process, which is similar to what might have occurred in some ancient underwater hydrothermal vents, may also have relevance to the search for life elsewhere in the universe.
New research led by the American Museum of Natural History and funded by NASA identifies a process that might have been key in producing the first organic molecules on Earth about 4 billion years ago, before the origin of life. The process, which is similar to what might have occurred in some ancient underwater hydrothermal vents, may also have relevance to the search for life elsewhere in the universe. Details of the study are published this week in the journal Proceedings of the National Academy of Sciences. …
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The researchers used their design to combine hydrogen with CO2to produce an organic molecule called formic acid (HCOOH). This synthetic process resembles the only known CO2-fixation pathway that does not require a supply of energy overall, called the Wood-Ljungdahl acetyl-CoA pathway. In turn, this process resembles reactions that might have taken place in ancient oceanic hydrothermal vents.
“The consequences extend far beyond our own biosphere,” Sojo said. “Similar hydrothermal systems might exist today elsewhere in the solar system, most noticeably in Enceladus and Europa – moons of Saturn and Jupiter, respectively – and so predictably in other water-rocky worlds throughout the universe.”
“Understanding how carbon dioxide can be reduced under mild geological conditions is important for evaluating the possibility of an origin of life on other worlds, which feeds into understanding how common or rare life may be in the universe,” added Laurie Barge from NASA’s Jet Propulsion Laboratory, an author on the study. …
Journal Reference:
Reuben Hudson, Ruvan de Graaf, Mari Strandoo Rodin, Aya Ohno, Nick Lane, Shawn E. McGlynn, Yoichi M. A. Yamada, Ryuhei Nakamura, Laura M. Barge, Dieter Braun, Victor Sojo. CO2 reduction driven by a pH gradient. Proceedings of the National Academy of Sciences, 2020; 202002659 DOI: 10.1073/pnas.2002659117
Thanks for the link. This tends to confirm my belief in Robert Hazen’s summation that life itself is not rare in the Universe . It took only a few hundred thousand years for abiogenesis to have started on earth, first with the self-formation of organic molecules.
Evolution by natural selection did the rest.
Intelligent life may be rare, but if there is only the probability of life on 1 in a million suitable planets, the universe is teeming with life.
The reduction of CO2 is not even a small step in understanding the origins of life. Everything I see started with a quantum perturbation. Wasn’t that complex?
Abiogenesis came much later from evolving complex chemical patterns.
How many times do I need to post this excellent lecture by Robert Hazen.
Once you have seen this you will have a much clearer perspective of how evolution via natural selection can lead to abiogenesis
We have observed all the necessary mechanics separately. We just haven’t been able to recreate the exact conditions and time scales that were necessary for biological systems to emerge and evolve into flora and fauna.
Pleas do watch this excellent presentation by one of the foremost experts in the world.
Start the video at 12:00 to avoid a lengthy introduction.
You question the chance for complex assemblies to form .
Hazen actually unpacks this and comes up with an estimated number of chemical reactions having occurred on earth and continuing.
Hold your hat; The earth has performed approximately; 2 billion, quadrillion, quadrillion, quadrillion chemical reactions.
Now can you see that speaking of chance is lazy thinking and that we can shift from looking at extremes to probabilities in between and in an ever changing dynamical environment there will be plenty of changing conditions for variation to occur.
Earth scientist Robert Hazen has an unusually rich research portfolio. He is trying to understand the carbon cycle from deep inside the Earth; chemical interactions at crystal-water interfaces; the interactions of organic molecules on mineral surfaces as a possible springboard to life; how life arose from the chemical to the biological world; how life emerges in extreme environments; and the origin and distribution of life in the universe just to name a few topics. In tandem with this expansive Carnegie work, he is also the Clarence Robinson Professor of Earth Science at George Mason University. He has authored more than 350 articles and 20 books on science, history, and music.
And you dare dismiss this eminent mind from your armchair, without any valid observations and counter argument?
What have you done in the field of abiogenesis study, that qualifies you to even venture a critique on the life-time work of a bona fide scientist? Get real!
That is just plain rude. If you disagree with the Carnegie Institute for Science, you will have to do a lot better than a meaningless knee-jerk dismissal!
A more logical defining equation : CO2 + H2 = HOOCH! = intoxication …
I believe Hazen already identified the formation of organic “vinegar” like substances in tectonic subductions of the earth’s crust.
The point being that in the formation of earth itself and the incalcuable number of different chemical reactions under the most extreme and different conditions, made abiogenesis not only probable, but most likely “necessary”.
At some point in the mindless chemical chaos there emerged a self-replicating organic polymer that required energy for duplication.
Consider that a not-quite-alive virus uses the chemical energy of the host’s cell for duplication (mitosis). BINGO!!!
Consider that not-quite-alive virus eats bacteria!!! BINGO!!!
** Gut bacteria: The surprising impact of viruses**
The microbiome plays a vital role in health. A recent study has investigated how viruses that kill gut bacteria influence these microbes. The findings make an already complicated picture much more so.
You might want to become familiar with the “Krebs cycle” and nature figured out how to get a free lunch out of the deal.
Enzyme-free Krebs cycle may have been key step in origin of life on Earth
Date: March 13, 2017
Source: The Francis Crick Institute
Summary: A set of biochemical processes crucial to cellular life on Earth could have originated in chemical reactions taking place on the early Earth four billion years ago, believes a group of scientists.
"… Metabolism is universal to life. It’s the set of processes through which we gain energy from food and produce the biomolecules we need in our body’s cells. The biochemical pathways that underpin these processes are highly similar across all organisms and species.
One central metabolic pathway learned by every A-level biology student is the Krebs cycle. But how did this essential set of chemical reactions, each step catalyzed by an enzyme, first arise? Each step in the cycle is not enough by itself. Life needs a sequence of these reactions, and it would have needed it before biological enzymes were around: Amino acids, the molecular components of enzymes, are made from products of the Krebs cycle.
The research group from the Francis Crick Institute and the University of Cambridge say their demonstration offers an answer. They have shown an enzyme-free metabolic pathway that mirrors the Krebs cycle. It is sparked by particles called sulphate radicals under conditions similar to those on Earth four billion years ago.
Senior author Dr Markus Ralser of the Francis Crick Institute and University of Cambridge explains: “This non-enzymatic precursor of the Krebs cycle that we have demonstrated forms spontaneously, is biologically sensible and efficient. It could have helped ignite life four billion years ago. …”
Yep, this is the cycle Hazen explains in his lecture on self-organizing self-replicating polymers as a required step in the evolutionary processes of Abiogenesis.
He posits that at this point, Darwinian evolution via natural selection begins to form the dynamic properties and speciation of living objects.
And IMO, here is when the first “microtubules” entered the stage during the prokaryotic stage.
These nanoscale self-organizing dipole coils regulate mitosis in ALL Eukaryotic organisms, which to me suggests that they are at least partially responsible for the evolutionary processes of all living things.
Look at this marvellous little machine that self-assembles from two “tubulins” (dimer)
They are long fibers (of indefinite length) about 24 nm in diameter.
In cross-section, each microtubule appears to have a dense wall of 6 nm thickness and light or hollow center. In cross-section, the wall of a microtubule is made up of 13 globular subunits, called protofilaments, about 4 to 5 nm in diameter.
Chemically, they are composed of two kinds of protein subunits: α-tubulin (tubulin A) and β-tubulin (tubulin B), each of M.W. 55,000 daltons.
The wall of a microtubule is made up of a helical array of repeating α and β tubulin subunits.
Assembly studies have indicated that the structural unit is an αβ dimer of 8 nm length.
Thus, in each microtubule, there are 13 protofilaments, each composed of αβ dimers that run parallel to the long axis of the tubule. The repeating unit is an αβ heterodimer which is arranged ‘head to tail’ within the microtubule, that is αβ→ αβ→αβ.
Thus, all microtubules have a defined polarity: their two ends are not structurally equivalent.
The human body has trillions of microtubules which make up the interior of the neural network.
Microtubules
Microtubules make up one of three major parts of the cytoskeleton (Figure 1). Similar to other cytoskeletal filaments, they play a major role in structural organization and cell shape, but they are also important in a number of other cellular processes, such as cell division, cell motility and intracellular transport. Microtubules form a polar network of filaments that extends from the centrosome towards the plasma membrane.
This organization is highly conserved in evolution, reflected in a striking similarity of microtubules across almost all species ([Janke C. (2014)]
Yeah I studied Krebs '72-5 at Lancaster. I have no problem with the fact of abiogenesis and that existence is self-organized by abstract meaningless mathematical principles.
Nobel laureate Jack Szostak from University of Chicago delivered the Eyring General Lecture on March 17, 2023 at Arizona State University. Please click here to learn more about Dr. Szosta and the distinguished Eyring Lecture Series at ASU. https://news.asu.edu/20230309-nobel-l…
