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New fossils push back the indisputable origin of life

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  • shunyadragon
    replied
    Originally posted by lee_merrill View Post
    I agree that it's unlikely that life could originate near a hydrothermal vent, and yet if life originated in the Hadean era, it's unlikely to have developed on land! Given all the meteorite bombardment that occurred shortly afterward.

    Source: Reasons to Believe

    Around 3.8 billion years ago, a gravitational perturbation in the early solar system sent asteroids towards Earth. Some estimates have the earth experiencing over 17,000 impact events during this time. This event, called the late heavy bombardment (LHB), was originally regarded as a sterilization event. If so, then any life present on Earth prior to the LHB would have been obliterated. That being the case, again, it appears as if complex microbial ecologies appeared on Earth suddenly, within a geological instant.

    Recently, some planetary scientists have challenged the notion that the LHB was a sterilization event. They argue that life on the planet’s surface would have been destroyed, but life in some environments, such as hydrothermal vents, could have survived. In other words, there would have been refugiums on Earth that served as “safe houses” for life, ushering it through the LHB.

    Yet the latest discovery by the Australian scientists doesn’t fit this scenario. The Isua stromatolites formed at the earth’s surface in a shallow water environment. In fact, the research team generated data that effectively ruled out stromatolite formation near hydrothermal vents. But if the refugium model has validity, the Isua fossils should have formed in a high-temperature milieu.

    Source

    © Copyright Original Source



    Blessings,
    Lee
    There is no evidence that life began in the Hadean Period, because The evidence for life is in the Archean where there are spreading zones, initial evidence of contenents and sedimentary rocks. Stop looking for rabbits in Hadean rocks, which do not exist. Despite the meteorite bombbardments life did eventually form by natural processes by the evidence.

    Leave a comment:


  • shunyadragon
    replied
    Originally posted by lee_merrill View Post
    But the Late Heavy Bombardment presents a problem to this scenario! See my response to rogue06...

    Blessings,
    Lee
    More Creationist speculation. There is absolutely no evidence that any of the bombardments destroyed everything from the Archean to Proterozoic. There is still evidence for life in these periods,

    Can you present evidence that your speculative Creationist speculations are true.

    Still waiting . . .

    Leave a comment:


  • lee_merrill
    replied
    Originally posted by shunyadragon View Post
    This speculation does not address the facts of abiogenesis origins of life. When continental formation began with crustal spreading zones, oceans forming and sedimentary deposits the conditions were right for abiogenesis to take place. There were millions of years in this time frame for life to begin. The only criteria is the environmental conditions must be present.
    But the Late Heavy Bombardment presents a problem to this scenario! See my response to rogue06...

    Blessings,
    Lee

    Leave a comment:


  • rogue06
    replied
    Originally posted by lee_merrill View Post
    I agree that it's unlikely that life could originate near a hydrothermal vent, and yet if life originated in the Hadean era, it's unlikely to have developed on land! Given all the meteorite bombardment that occurred shortly afterward.
    Cosmic impacts take place at sea as well.

    Leave a comment:


  • lee_merrill
    replied
    Originally posted by rogue06 View Post
    Of course there are competing theories about life first arising from shallow ponds and hot springs, IIRC, largely because such locations would be rich in nitrogen which ancient seas might have been low on.
    ...

    So be careful of doing battle with the very sort of evidence that caused the shift from deep sea vents as if this were something new and unexplained. You can quickly find yourself combatting straw men if you end up battling an idea that is losing support.
    I agree that it's unlikely that life could originate near a hydrothermal vent, and yet if life originated in the Hadean era, it's unlikely to have developed on land! Given all the meteorite bombardment that occurred shortly afterward.

    Source: Reasons to Believe

    Around 3.8 billion years ago, a gravitational perturbation in the early solar system sent asteroids towards Earth. Some estimates have the earth experiencing over 17,000 impact events during this time. This event, called the late heavy bombardment (LHB), was originally regarded as a sterilization event. If so, then any life present on Earth prior to the LHB would have been obliterated. That being the case, again, it appears as if complex microbial ecologies appeared on Earth suddenly, within a geological instant.

    Recently, some planetary scientists have challenged the notion that the LHB was a sterilization event. They argue that life on the planet’s surface would have been destroyed, but life in some environments, such as hydrothermal vents, could have survived. In other words, there would have been refugiums on Earth that served as “safe houses” for life, ushering it through the LHB.

    Yet the latest discovery by the Australian scientists doesn’t fit this scenario. The Isua stromatolites formed at the earth’s surface in a shallow water environment. In fact, the research team generated data that effectively ruled out stromatolite formation near hydrothermal vents. But if the refugium model has validity, the Isua fossils should have formed in a high-temperature milieu.

    Source

    © Copyright Original Source



    Blessings,
    Lee

    Leave a comment:


  • shunyadragon
    replied
    Originally posted by lee_merrill View Post
    Well, they say now that the origin of life probably happened in the Hadean era:

    Source: Nature

    A sophistication of life by 3,700 Ma is in accord with genetic molecular clock studies placing life's origin in the Hadean eon (>4,000 Ma).

    © Copyright Original Source


    So the origin of life would probably be in the oceans (near smokers?), where the large quantity of water would tend to dilute any reactions.

    Source: Reasons to Believe

    Yet the latest discovery by the Australian scientists doesn’t fit this scenario. The Isua stromatolites formed at the earth’s surface in a shallow water environment. In fact, the research team generated data that effectively ruled out stromatolite formation near hydrothermal vents. But if the refugium model has validity, the Isua fossils should have formed in a high-temperature milieu.

    Source

    © Copyright Original Source


    Also, we may note that reducing the timeframe for the origin of life by 220 million years doesn't leave much time for the origin of life! And having life originate in the Hadean era is going to be more difficult.

    Blessings,
    Lee
    This speculation does not address the facts of abiogenesis origins of life. When continental formation began with crustal spreading zones, oceans forming and sedimentary deposits the conditions were right for abiogenesis to take place. There were millions of years in this time frame for life to begin. The only criteria is the environmental conditions must be present. The boundary between the Hadean and the Archean is not that exact. The conditions described are representative of the Archean.

    There are no known rock formation dated in the Hasean. The formations described in this research are Archean.

    As with other threads there is a problem with your speculation to justify an ID Creationist belief not science.
    Last edited by shunyadragon; 07-11-2021, 11:06 AM.

    Leave a comment:


  • rogue06
    replied
    Of course there are competing theories about life first arising from shallow ponds and hot springs, IIRC, largely because such locations would be rich in nitrogen which ancient seas might have been low on.

    For instance, here's the abstract from a paper on just that subject Nitrogen Oxide Concentrations in Natural Waters on Early Earth (the entire paper is available by clicking on the hyperlink) from 2019.


    Abstract

    A key challenge in origins-of-life studies is estimating the abundances of species relevant to the chemical pathways proposed to have contributed to the emergence of life on early Earth. Dissolved nitrogen oxide anions ( ), in particular nitrate ( ) and nitrite ( ), have been invoked in diverse origins-of-life chemistry, from the oligomerization of RNA to the emergence of protometabolism. Recent work has calculated the supply of from the prebiotic atmosphere to the ocean and reported steady state [ ] to be high across all plausible parameter space. These findings rest on the assumption that is stable in natural waters unless processed at a hydrothermal vent. Here, we show that is unstable in the reducing environment of early Earth. Sinks due to ultraviolet photolysis and reactions with reduced iron (Fe2+) suppress [ ] by several orders of magnitude relative to past predictions. For pH = 6.5–8 and T = 0–50 C, we find that it is most probable that [ ] <1μM in the prebiotic ocean. On the other hand, prebiotic ponds with favorable drainage characteristics may have sustained [ ] ≥1μM. As on modern Earth, most on prebiotic Earth should have been present as , due to its much greater stability. These findings inform the kind of prebiotic chemistries that would have been possible on early Earth. We discuss the implications for proposed prebiotic chemistries and highlight the need for further studies of kinetics to reduce the considerable uncertainties in predicting [ ] on early Earth.



    And here's a nice piece on both the history and current state OOL research from Nature last year: How the first life on Earth survived its biggest threat -- water: Living things depend on water, but it breaks down DNA and other key molecules. So how did the earliest cells deal with the water paradox? where the researchers posit even shallower water:

    The emerging evidence has caused many researchers to abandon the idea that life emerged in the oceans and instead focus on land environments, in places that were alternately wet and dry. The shift is hardly unanimous, but scientists who support the idea of a terrestrial beginning say it offers a solution to a long-recognized paradox: that although water is essential for life, it is also destructive to life’s core components.


    So be careful of doing battle with the very sort of evidence that caused the shift from deep sea vents as if this were something new and unexplained. You can quickly find yourself combatting straw men if you end up battling an idea that is losing support.
    Last edited by rogue06; 07-10-2021, 06:21 PM.

    Leave a comment:


  • lee_merrill
    replied
    Originally posted by shunyadragon View Post
    OK. Good science. This fits the beginning of life with the formation of spreading zones, continental drift, early continents, oceans and sediment deposits. Now what?
    Well, they say now that the origin of life probably happened in the Hadean era:

    Source: Nature

    A sophistication of life by 3,700 Ma is in accord with genetic molecular clock studies placing life's origin in the Hadean eon (>4,000 Ma).

    © Copyright Original Source


    So the origin of life would probably be in the oceans (near smokers?), where the large quantity of water would tend to dilute any reactions.

    Source: Reasons to Believe

    Yet the latest discovery by the Australian scientists doesn’t fit this scenario. The Isua stromatolites formed at the earth’s surface in a shallow water environment. In fact, the research team generated data that effectively ruled out stromatolite formation near hydrothermal vents. But if the refugium model has validity, the Isua fossils should have formed in a high-temperature milieu.

    Source

    © Copyright Original Source


    Also, we may note that reducing the timeframe for the origin of life by 220 million years doesn't leave much time for the origin of life! And having life originate in the Hadean era is going to be more difficult.

    Blessings,
    Lee

    Leave a comment:


  • shunyadragon
    replied
    Originally posted by lee_merrill View Post
    The first fossils of life are now at 3.7 billion years ago, about 220 million years earlier than the previous early fossils.

    Source: Nature

    Here we report evidence for ancient life from a newly exposed outcrop of 3,700-Myr-old metacarbonate rocks in the ISB that contain 1-4-cm-high stromatolites-macroscopically layered structures produced by microbial communities. The ISB stromatolites grew in a shallow marine environment, as indicated by seawater-like rare-earth element plus yttrium trace element signatures of the metacarbonates, and by interlayered detrital sedimentary rocks with cross-lamination and storm-wave generated breccias. The ISB stromatolites predate by 220 Myr the previous most convincing and generally accepted multidisciplinary evidence for oldest life remains in the 3,480-Myr-old Dresser Formation of the Pilbara Craton, Australia. The presence of the ISB stromatolites demonstrates the establishment of shallow marine carbonate production with biotic CO2 sequestration by 3,700 million years ago (Ma), near the start of Earth's sedimentary record.

    Source

    © Copyright Original Source



    Blessings,
    Lee
    OK. Good science. This fits the beginning of life with the formation of spreading zones, continental drift, early continents, oceans and sediment deposits. Now what?
    Last edited by shunyadragon; 07-09-2021, 05:25 PM.

    Leave a comment:


  • New fossils push back the indisputable origin of life

    The first fossils of life are now at 3.7 billion years ago, about 220 million years earlier than the previous early fossils.

    Source: Nature

    Here we report evidence for ancient life from a newly exposed outcrop of 3,700-Myr-old metacarbonate rocks in the ISB that contain 1-4-cm-high stromatolites-macroscopically layered structures produced by microbial communities. The ISB stromatolites grew in a shallow marine environment, as indicated by seawater-like rare-earth element plus yttrium trace element signatures of the metacarbonates, and by interlayered detrital sedimentary rocks with cross-lamination and storm-wave generated breccias. The ISB stromatolites predate by 220 Myr the previous most convincing and generally accepted multidisciplinary evidence for oldest life remains in the 3,480-Myr-old Dresser Formation of the Pilbara Craton, Australia. The presence of the ISB stromatolites demonstrates the establishment of shallow marine carbonate production with biotic CO2 sequestration by 3,700 million years ago (Ma), near the start of Earth's sedimentary record.

    Source

    © Copyright Original Source



    Blessings,
    Lee

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