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Advances in the science of abiogenesis

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  • shunyadragon
    replied
    Originally posted by lee_merrill View Post
    This is not complicated, they claimed to have synthesized RNA, but they only synthesized some of RNA's building blocks. Their stated next step was to synthesize ribose, another component of RNA.

    Blessings,
    Lee
    You are perpetually arguing from ignorance, and often ignoring the advancements of scientific research and discoveries concerning the origins of RNA/DNA.

    Leave a comment:


  • lee_merrill
    replied
    Originally posted by shunyadragon View Post
    No it is not. You lack the fundamental knowledge in the biological science to make such a statement.
    This is not complicated, they claimed to have synthesized RNA, but they only synthesized some of RNA's building blocks. Their stated next step was to synthesize ribose, another component of RNA.

    Blessings,
    Lee

    Leave a comment:


  • shunyadragon
    replied
    Originally posted by lee_merrill View Post
    I noted a claim that RNA had been synthesized, "RNA has been synthesized in conditions that may have resembled those on the early Earth." Only they didn't synthesize RNA, so this claim is false.
    No it is not. You lack the fundamental knowledge in the biological science to make such a statement.

    Well, without homochirality you don't get a biomolecule, in all probability.
    Probability is absolutely meaningless without a falsifiable hypothesis. Besides it is meaningless anyway, because as previously referenced it is a false method to evaluate abiogenesis and evolution, because it is based on the assumptions of a religious agenda, and not legitimate scientific evidence and methods.

    Leave a comment:


  • lee_merrill
    replied
    Originally posted by shunyadragon View Post
    Where do who synthesize RNA?
    I noted a claim that RNA had been synthesized, "RNA has been synthesized in conditions that may have resembled those on the early Earth." Only they didn't synthesize RNA, so this claim is false.

    There are no dents in claims, nor claims as you interpret them. Scientific knowledge builds over time with progressive research and discoveries.
    Well, without homochirality you don't get a biomolecule, in all probability.

    Blessings,
    Lee

    Leave a comment:


  • shunyadragon
    replied
    Originally posted by lee_merrill View Post
    So where do they synthesize RNA?
    Where do who synthesize RNA? The goal of the research over time to determine various ways RNA can come about naturally.


    But is it racemic? Probably so, and if so, puts a dent in their claim.

    Blessings,
    Lee
    There are no dents in claims, nor claims as you interpret them. Scientific knowledge builds over time with progressive research and discoveries.

    Leave a comment:


  • lee_merrill
    replied
    Originally posted by shunyadragon View Post
    No, it does not claim too much it claims what it claims read again...
    So where do they synthesize RNA?

    Source: https://www.sciencealert.com/researchers-find-that-ribose-the-r-in-rna-may-form-naturally-in-space


    Researchers Find That Ribose, The 'R' in RNA, Could Form Naturally in Space

    © Copyright Original Source

    But is it racemic? Probably so, and if so, puts a dent in their claim.

    Blessings,
    Lee

    Leave a comment:


  • shunyadragon
    replied
    Originally posted by lee_merrill View Post
    It seems they synthesized the bases for RNA, but not RNA itself, for RNA, you need ribose. This statement claims too much, as does the claim that they can form under one set of conditions, which turns out to be two sets of conditions.

    Blessings,
    Lee
    No, it does not claim too much it claims what it claims read again, but . . .

    Source: https://www.sciencealert.com/researchers-find-that-ribose-the-r-in-rna-may-form-naturally-in-space


    Researchers Find That Ribose, The 'R' in RNA, Could Form Naturally in Space
    JOSH HRALA8 APR 2016

    Though the quest to find water on distant planets is the most talked-about way that researchers are looking for extraterrestrial life, one of our best bets at understanding life’s complexities lies with comets, not planets.


    In fact, the icy space balls are already known to form amino acids and nucleobases, two key substances needed for life to take root. And now, researchers may have found another necessary ingredient: ribose, the 'R' in RNA.

    Before we dive into the new discovery, it’s important to understand what life, as we know it, needs to get started, and how we think it may have happened here on Earth. Life on Earth requires three macromolecules: RNA, DNA and proteins. The current understanding is that RNA, or ribonucleic acid, came before DNA on Earth.

    However, the conditions needed for ribose, a simple sugar needed for RNA, were not formed yet on Earth before life started. So, the question remained: where did ribose come from?

    To answer this, the team of researchers led by chemist Cornelia Meinert from the University Nice Sophia Antipolis in France, set out to recreate the conditions of our early Solar System to see whether or not ribose could form, Deborah Netburn reports for the Los Angeles Times.

    This process involved freezing water, ammonia, and methanol to -195 degrees Celsius, which basically created a fake comet in the lab. Then, when temperatures were right, they blasted it with ultraviolet light so that the 'comet' would experience the same type of radiation that a young star would produce. The last step was to let the comet warm back up and see what molecules were created.

    The team discovered about 55 organic molecules were present after analysis, with the most important and exciting being ribose. Though this same experiment had been done countless times across the globe in the past, this team is the first to use multidimensional gas chromatography, a new technique that makes detecting individual molecules easier.

    "Our ice simulation is a very general process that can occur in molecular clouds as well as in protoplanetary disks. It shows that the molecular building blocks of the potentially first genetic material are abundant in interstellar environments," Meinert explains.

    The discovery hints that ribose from comets or dust clouds might have fallen onto a young Earth, establishing a needed building block for life.

    But there are still a few things for researchers to figure out. For example, this study was done in a lab, which means we will need to back up the findings by discovering ribose on a real comet or in a real dust cloud. Also, the team also doesn’t know when the ribose actually formed. Was it the heating or the cooling that did the trick?

    With any luck, researchers will have these answers in the coming years, with many more missions focusing on comets coming in the near future. Despite its shortcomings, the discovery is a big step in understanding how life on Earth - and possibly elsewhere in the Universe - formed.

    The team’s study was published in Science.

    © Copyright Original Source

    Leave a comment:


  • lee_merrill
    replied
    Originally posted by shunyadragon View Post
    Back to REAL science.

    Source: https://www.nature.com/articles/d41586-019-02622-4



    Lab-made primordial soup yields RNA bases

    The chemical feat strengthens theory that the first life on Earth was based on RNA.


    Single strand ribonucleic acid, RNA research and therapy.
    RNA has been synthesized in conditions that may have resembled those on the early Earth.

    © Copyright Original Source

    It seems they synthesized the bases for RNA, but not RNA itself, for RNA, you need ribose. This statement claims too much, as does the claim that they can form under one set of conditions, which turns out to be two sets of conditions.

    Blessings,
    Lee

    Leave a comment:


  • shunyadragon
    replied
    The problem of phosphorus in the abiogenesis of life may be resolved. Phosphorus is necessary for abiogenesis, but the problem was how it could naturally avaialble for the beginning of life.

    Source: https://www.pnas.org/content/early/2019/12/26/1916109117



    A carbonate-rich lake solution to the phosphate problem of the origin of life
    Jonathan D. Toner and View ORCID ProfileDavid C. Catling
    PNAS first published December 30, 2019 https://doi.org/10.1073/pnas.1916109117

    Significance
    Phosphate is crucial for the origin of life because it is ubiquitous in key biomolecules. A major issue is that prebiotic syntheses use concentrated phosphate to incorporate phosphate into biomolecules, whereas natural waters are generally phosphate-poor because phosphate reacts with calcium to form low-solubility apatite minerals. Here we show that carbonate-rich lakes can concentrate phosphate to >1 molal levels by locking up calcium in carbonate minerals, which prevents phosphate removal by apatite precipitation. Phosphate-rich lakes may have preferentially formed on the prebiotic Earth because of carbonic acid weathering under CO2-rich atmospheres and the absence of microbial phosphate consumption. This specifically points to an origin of life in carbonate-rich lakes, and so defines aqueous conditions that prebiotic chemists should consider.

    Abstract
    Phosphate is central to the origin of life because it is a key component of nucleotides in genetic molecules, phospholipid cell membranes, and energy transfer molecules such as adenosine triphosphate. To incorporate phosphate into biomolecules, prebiotic experiments commonly use molar phosphate concentrations to overcome phosphate’s poor reactivity with organics in water. However, phosphate is generally limited to micromolar levels in the environment because it precipitates with calcium as low-solubility apatite minerals. This disparity between laboratory conditions and environmental constraints is an enigma known as “the phosphate problem.” Here we show that carbonate-rich lakes are a marked exception to phosphate-poor natural waters. In principle, modern carbonate-rich lakes could accumulate up to ∼0.1 molal phosphate under steady-state conditions of evaporation and stream inflow because calcium is sequestered into carbonate minerals. This prevents the loss of dissolved phosphate to apatite precipitation. Even higher phosphate concentrations (>1 molal) can form during evaporation in the absence of inflows. On the prebiotic Earth, carbonate-rich lakes were likely abundant and phosphate-rich relative to the present day because of the lack of microbial phosphate sinks and enhanced chemical weathering of phosphate minerals under relatively CO2-rich atmospheres. Furthermore, the prevailing CO2 conditions would have buffered phosphate-rich brines to moderate pH (pH 6.5 to 9). The accumulation of phosphate and other prebiotic reagents at concentration and pH levels relevant to experimental prebiotic syntheses of key biomolecules is a compelling reason to consider carbonate-rich lakes as plausible settings for the origin of life.

    © Copyright Original Source

    Leave a comment:


  • shunyadragon
    replied
    Source: https://www.rt.com/news/470167-saturn-moon-precursors-life/



    ‘Ideal precursors’ of LIFE found on Saturn’s icy ocean moon, scientists say

    Deep under its frozen primordial oceans, Saturn’s moon Enceladus may conceal the building blocks for life, according to recent research. The finding raises exciting new questions about whether mankind is alone in the cosmos.
    Scouring vast amounts of data transmitted by NASA’s Cassini probe, researchers discovered Enceladus was emitting “new kinds of organic compounds” in ice plumes ejected from its subsurface oceans. The substances could make “ideal precursors” for the “synthesis of biologically relevant organic compounds,” including amino acids, which make up proteins and play a litany of other roles in life as Earthlings know it.

    The researchers posited that hydrothermal vents under Enceladus’ oceans are responsible for pushing the compounds into the ice plumes analyzed by Cassini, and said if those vents operate under similar principles to those found on Earth, they could eventually transform the chemicals into amino acids.

    © Copyright Original Source

    Leave a comment:


  • shunyadragon
    replied
    Back to REAL science.

    Source: https://www.nature.com/articles/d41586-019-02622-4



    Lab-made primordial soup yields RNA bases

    The chemical feat strengthens theory that the first life on Earth was based on RNA.


    Single strand ribonucleic acid, RNA research and therapy.
    RNA has been synthesized in conditions that may have resembled those on the early Earth.Credit: Alamy

    If Thomas Carell is right, around 4 billion years ago, much of Earth might have been blanketed with a greyish-brown kind of mineral. This was no ordinary rock, however: it consisted of crystals of the organic molecules that scientists now call A, U, C and G. And some of these, the theory goes, would later serve as the building blocks of RNA, the evolutionary engine of the first living organisms, before DNA existed.

    Carell, an organic chemist, and his collaborators have now demonstrated a chemical pathway that — in principle — could have made A, U, C and G (adenine, uracil, cytosine and guanine, respectively) from basic ingredients such as water and nitrogen under conditions that would have been plausible on the early Earth. The reactions produce so much of these nucleobases that, millennium after millennium, they could have accumulated in thick crusts, Carell says. His team describes the results in Science on 3 October1.

    The results add credence to the ‘RNA world’ hypothesis, says Carell, who is at the Ludwig Maximilian University of Munich in Germany. This idea suggests that life arose from self-replicating, RNA-based genes — and that only later did organisms develop the ability to store genetic information in the molecule’s close relative, DNA. The chemistry is also a “strong indication” that the appearance of RNA-based life was not an exceedingly lucky event, but one that is likely to happen on many other planets, he adds.

    In previous work in 2016, Carell’s team had found chemical reactions that spontaneously yielded the nucleobases A and G2. A separate group had done a similar proof-of-principle3 for the other two, U and C in 2009. But the two pathways seemed incompatible with each other, requiring different conditions, such as divergent temperatures and pH.

    Now, Carell’s team has shown how all nucleobases could form under one set of conditions: two separate ponds that cycle through the seasons, going from wet to dry, from hot to cold, and from acidic to basic, and with chemicals occasionally flowing from one pond to the other. The researchers first let simple molecules react in hot water and then allowed the resulting mix to cool down and dry up, forming a residue at the bottom that contained crystals of two organic compounds.

    They then added water back, and one of the compounds dissolved and was washed away into another reservoir. The absence of that water-soluble molecule allowed the other compound to undergo further reactions. The researchers then mixed the products again, and their reactions formed the nucleobases.

    “This paper has demonstrated marvellously the chemistry that needs to take place so you can make all the RNA nucleosides,” says Ramanarayanan Krishnamurthy, a chemist at Scripps Research in La Jolla, California. But he and other researchers often warn that this and similar results are based on hindsight and might not offer credible guidance as to how life actually evolved.

    The next major problem Carell wants to tackle is what reactions could have formed the sugar ribose, which needs to link to nucleobases before RNA can form.

    References

    1. Becker, S. et al. Science 366, 76–82 (2019).

    Google Scholar

    2. Becker, S. et al. Science 352, 833–836 (2016).

    Pub Med Article Google Scholar

    3. Powner, M. W., Gerland, B. & Sutherland, J. D. Nature 459, 239–242 (2009).

    © Copyright Original Source

    Leave a comment:


  • Teallaura
    replied
    Originally posted by TheLurch View Post
    Hope you're feeling better.

    Specifics are kind of what i'm asking for. I accept that any science is liable to error - it's done by humans, after all. But you keep saying "skew" is a risk, and you keep calling experiments like this designed, and i'm asking for specifics: what exactly could be skewed when an experiment is (to give a hypothetical) just starting with a bunch of chemicals that we've observed on comets? What's the element of design in doing that?
    Thanks!


    We know (in the epistemological sense) comets represent the early earth? The weakest link in any argument is the assumptions it's predicated on - like assuming (I'm presuming with darn good reason) that comets reflect the early earth.

    I'm arguing two different things - and we seem to agree on one. Intellect/design/human propensity for error are interlinked in my argument regarding methodology. And you hit on it with "it's done by humans, after all". Operative term is 'done'. Intellect (where we started this) is integral to experimentation - someone has to figure out how to neutrally contain all those comet chemicals at the very least. Designing an experiment is in fact a form of design.

    For methodology - selecting which chemicals go in which cup and in what amounts and when they will be combined - all that 'design' - my point is merely that we humans not only make factual errors but errors of assumption - the later will be most likely in the design phase. For example, are we using comets or ice cores to guide our choices in what experiment to do. Our assumptions of how well each reflects the early earth guides the choice - but even well founded assumptions can be wrong.

    Your example 'starts' at the end - we've decided comets work best and are ready to start mixing stuff. But the design phase beings well before we're slinging flasks around (chem lab is not for the faint of heart - at least it wasn't at NMIMT!) - it's in the decision making, not the flasks.




    The second argument is the one with Shuny about using a designed experiment of any sort to prove naturalism (can't). That hasn't diddly-squat to do with experimental design (other than the fact of) or methodology. And no, it's of no issue with what you pour in your flasks.

    Hmm, was that the problem? Design comes into play in both but in vastly different ways.


    With 50,000 and counting, I get the feeling sometimes that English needs more words!
    Last edited by Teallaura; 10-03-2019, 11:33 PM.

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  • TheLurch
    replied
    Originally posted by Teallaura View Post
    The problem persists because humans be humans - there's always the potential for skew/error when people design anything, including experiments. But the exacerbation I suspect occurs in computer modelling wouldn't be at issue.

    Beyond that I don't want to tackle epistemological questions outside specifics - you touched on the same several posts ago.
    Hope you're feeling better.

    Specifics are kind of what i'm asking for. I accept that any science is liable to error - it's done by humans, after all. But you keep saying "skew" is a risk, and you keep calling experiments like this designed, and i'm asking for specifics: what exactly could be skewed when an experiment is (to give a hypothetical) just starting with a bunch of chemicals that we've observed on comets? What's the element of design in doing that?

    Leave a comment:


  • shunyadragon
    replied
    Originally posted by Teallaura View Post
    Which defeats your postulate. One cannot use design to disprove design.
    There is no effort to disprove Intelligent Design by science.

    Science does not prove nor disprove anything. The Discovery Institute for Intelligent design has failed to provide any falsifiable hypothesis to support Intelligent Design.

    Still waiting . . .
    Last edited by shunyadragon; 10-03-2019, 08:14 PM.

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  • Teallaura
    replied
    Originally posted by shunyadragon View Post
    The introduction of intelligence is human intelligence. Science is descriptive using theories, hypothesis, and models to simulate natural process based on the nature and limits of the Laws of Nature. The only intelligence involved in science is human intelligence.
    Which defeats your postulate. One cannot use design to disprove design.

    Leave a comment:

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