How does one demonstrate that something doesn’t exist today? Even sillier, how does one demonstrate that a particular condition never existed?
You’re confusing the average concentration in the Earth’s crust with the concentration found in a particular mineral structure that results from the slow precipitation and build-up when hydrothermal fluids mix with sea-water on the ocean floor.
The concentration of calcium in my tap water is very low, in an absolute sense. Much lower than the average concentration in the Earth’s crust (about 4.2% according to google), but I still get limescale in my sink. Guess what the concentration of calcium is in those deposits?
Once again you’re confused. They buy 98% pure nickel salt, then mix it with water and a few other reactants to a final concentration of 5mM simply in order to get a precipitate to form:
Precipitation of Fe(Ni)S at the Interface in a Gas-Driven Y-Shaped Microfluidic Reactor.
Aiming to coincide with fluid compositions in previous work (5, 30, 31), and as detailed in SI Appendix, Table S1, we prepared an alkaline vent-simulant fluid containing Na2S (100 mM), K2HPO4 (10 mM), and Na2Si3O7 (10 mM) in deaerated water. The counterpart ocean analog fluid contained FeCl2 (50 mM) and NiCl2 (5 mM). The two fluids were introduced at the inlets of a Y-shaped borosilicate microfluidic reactor (Fig. 1B).
Of course sea water or hydrothermal fluids don’t contain those concentrations of iron or nickel sulfide either. That’s not the point. They’re not trying to re-create the speed at which such a mineral precipitates. That takes centuries. They’re just trying to get the barrier to form in the first place because, once formed, it is hypothesized to have interesting properties.
We split each reactor run into two consecutive stages, the first for deposition of the Fe(Ni)S precipitates at the interface between the two fluids and the second (referred to as “postprecipitation” below) for attempting the reaction between CO2 and H2 (or other reagents, as detailed where relevant). Confluence of the ocean and vent analogs over 15 to 60 s in the precipitation stage yielded a 30- to 60-µm-wide precipitate at the interface between the two fluids, visible under a digital 200× optical microscope (Fig. 1B, Center ). Removing metals from the ocean side following precipitation prevented the precipitate from growing to the point of occluding the reactor channel.
There wouldn’t need to be 98% pure nickel salt on the early Earth to get an iron-nickel-sulfide mineral where the local concentration is higher than 0.01%. But the researchers don’t have decades or centuries to wait for the slow accumulation and build-up of an iron-nickel precipitate when the fluids meet on the ocean floor. The point is to re-create the iron-nickel-sulfite-containing inorganic barrier also found in real hydrothermal vents, to see if the barrier can act as a membrane.
Think about how many elements are trace elements, in that their average concentration in the Earth’s crust is very low, but they’re nevertheless found in ores and deposits where their local concentration is very high. The average iron concentration is only 5.5% as you quote, but is found locally in ores and deposits at percentages much higher than that. Famously the banded iron formations that resulted from oxygenation of Earth’s oceans.
There are nickel containing minerals, such as Pentlandite, where nickel is found locally at concentrations as high as 34%: Pentlandite Mineral Data
By your above displayed thinking that should be impossible, right?
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Blockquote Because it’s not about anyone’s feelings. It’s about the evidence that you and Tour ignore
I didn’t ignore any evidence for any OOL hypotheses. The popular hypotheses all assume that life emerges from natural environmentally controlled chemical reactions something for which there is plenty of proposals, no real evidence. No one denies that the basic building blocks of life can be found in nature, just like the basic building blocks of all our modern technology can be found in the natural world as well.
Building blocks are not sufficient to explain the existence of either our technologies or the cell. To build our technology we need to be able to extract materials from nature, segregate them for processing, refining manufacture and transport. Of course we also need intelligent agents to actually create the tech and manage all of the above processes. This is a civilizational endeavor that may some day be fully automated.
Cells face all of the same challenges as our collective civilization and accomplish the same feats in a fully autonomous manner. Cells extract, refine, manufacture and transport all of the materials necessary for their survival on an ongoing and adaptive basis. Understanding how cells solve these problems is a huge computational challenge, while replicating these processes is a bigger computational challenge one well beyond the reach of mindless geochemical processes.
You asked for a testable origin of hypothesis but I would just like to see OOL theorists test that actual hypothesis that unguided natural processes can cause cells to emerge. If someone thinks that iron based metabolism emerged in the sea why not test iron silicates as actually existed in nature as opposed to pure iron. Never stop reactions artificially let them go unabated and see what happens. Why not use realistic concentrations of reagents, etc? I think such honest research would help everyone understand what natural processes are actually capable of as opposed to synthetic chemists.
We have an actual natural example of alkaline deep sea vents at Lost City and I the rocks that formed it are called olivine as explained below:
Blockquote The vents are formed by a process known as serpentinization. Seabed rock, in particular olivine (magnesium iron silicate) reacts with water and produces large volumes of hydrogen. In the Lost City, when the warm alkaline fluids (45–90°C and pH 9–11) are mixed with seawater, they create white calcium carbonate chimneys 30–60m tall
Olivine is a common mineral in the earth’s crust that is less than .05 percent Nickel by weight. More importantly it is a silicate. Pentlandite in nature is has the highest Ni composition in surface and mantle rocks usually found in silica poor as explained here:
Blockquote
pentlandite , a nickel and iron sulfide mineral, the chief source of nickel. It is nearly always found with pyrrhotite and similar minerals in silica-poor rocks such as those at Bushveld, S.Af.; Bodø, Nor.; and Sudbury, Ont., Can. It has also been found in meteorites
If the goals is to simulate nature why not actually nature? Alkaline vents as explained above form from rocks with small concentrations of Ni but lots of Mg, Si, Ca and Fe. So why not limit tests to realistic concentrations of those reagents? If it doesn’t work and it hasn’t that is a valid result.
While that is actually false, it also amounts to a vacuous argument from ignorance.
Did you know that there’s a branch of research in the origin of life trying to determine what sorts of processes could have given rise to cells, and how something analogous to replication and evolution could have occurred even before cells?
Well now that you’ve committed that assertion to text it must be true.
They are in the process of doing that very thing. Finding out what sorts of processes could operate in nature, where, and what might result from them.
I have no idea what you’re referring to, but are you aware that researchers are testing the catalytic properties of naturally occurring iron bearing minerals? Not just “iron silicates”. There are many types of naturally occuring iron mineral deposits, and iron is not just distributed evenly and only as part of silicates.
I’m sorry but you read like someone who gets all their information from James Tour. Painfully ignorant of what is going on in the field, of what actually exists in nature, and what scientists who work in the OOL field are actually doing. One of which is to actually talk to geologists, physicists, and astronomers, to try to determine the early evolution of Earth’s geology and environments.
Another misconception foisted upon you by James Tour is this idea that scientists who have studied closed systems (an enclosure like a flask doped with some basic chemicals is cooked/sparked continously for a long time) aren’t aware that those same closed systems produce tar when they just keep running.
One of the problems (well recognized by everyone working in the field) with the Miller Urey experiment and similar experiments of the type, was that the system could not exchange materials with the surroundings, so the same molecules just kept reacting with each other becoming ever more complex.
But nature doesn’t contain closed systems in that way, in which products can enter initially, then the source is shut off and nothing can leave and products are just fed back on themselves in an endless cycle. In open systems under continuos flow and dilution, like they exist in nature, there are circumstances where they don’t produce tars because excess products can wash away, and there is a continued feed-stock of simpler building blocks.
Scientists are already working to set up such systems that more appropriately mimic natural conditions. Open systems with fluctuating conditions that run for much longer periods of time, while being capable of exchanging materials with their “surroundings”. For example by allowing products to flow in, serially dilute resulting systems, but also leave and carry away products.
Allow me to introduce you to the idea of a controlled experiment, one in which the experimenter sets up two or more situations which vary only by a single factor or degree of a factor, then observes the outcome. This is essential to basic science because it allows the experimenter to establish cause. If you don’t do that, you wind up with an uncontrolled (or “observational”) experiment - this allows the experimenter to observe associations but not to establish cause.
That’s why we don’t just throw stuff at a wall and see what happens - it might be interesting, but it’s a really bad way to sort out the details
of what actually happens.
PS: It is sometimes possible to observe “natural experiments”, where it may still be possible to determine cause from observational data. How this works is not very relevant to this discussion, except to note that controlled experiments are a much more efficient way to determine cause that throwing stuff at the wall.
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First of all can you please provide a direct response to my correction of your misapprehension of the use of a 98% pure NiCl2 salt? I’d like to know if you even understood the point that the purity of the salt, as bought, is not relevant to the composition of the fluid they later produce? I mean, I really hope you understand that, if I want to create a simulacrum of salt water as found in the oceans(not that this was their goal either, but I digress), with it’s ~3.5% salt concentration, I can buy pure salt and just dissolve 35g of it in 1L water to a final concentration of 3.5%, right? Do I need to buy it at 3.5% to begin with, or am I allow to buy it pure and mix it to that final concentration?
You are confusing the rock material that reacts with seawater to produce hydrogen in the process of serpentinization, with the composition of the hydrothermal chimney itself. The compositon of the hydrothermal chimney is partly a product of both the minerals dissolved in the surrounding sea water, and the particular geology underlying the specific hydrothermal field.
In Lost City, the chimney walls are made primarily of Calcium Carbonate)(CaCO3). Not silicate.
The Strýtan alkaline hydrothermal field in Iceland is depositing Magnesium silicate minerals(MgSiO2) instead of calcium carbonates like in lost city. It’s an alkaline hydrothermal vent but isn’t even hosted by a serpentinizing system.
Fossil hydrothermal chimneys have been discovered that consist of iron sulfides. One of the products of serpentinization is iron-nickel bearing minerals such as awaruite:
Formation and petrology
Serpentinization is a form of low-temperature (0 to ~600 °C) [5] metamorphism of ferromagnesian minerals in mafic and ultramafic rocks, such as dunite, harzburgite, or lherzolite. These are rocks low in silica and composed mostly of olivine ((Mg2+, Fe2+)2SiO4), pyroxene (XY(Si,Al)2O6), and chromite (approximately FeCr2O4). Serpentinization is driven largely by hydration and oxidation of olivine and pyroxene to serpentine group minerals (antigorite, lizardite, and chrysotile), brucite (Mg(OH)2), talc (Mg3Si4O10(OH)2, and magnetite (Fe3O4).[2] Under the unusual chemical conditions accompanying serpentinization, water is the oxidizing agent, and is itself reduced to hydrogen, H2. This leads to further reactions that produce rare iron group native element minerals, such as awaruite (Ni3Fe) and native iron; methane and other hydrocarbon compounds; and hydrogen sulfide.[1][6]
Are you aware the composition of the Earth’s oceans, and the constituents of alkaline hydrothermal fluids, are not and have not always been the same? And they’re not the same all over the world even now? The concentration of Ni, for example, is thought to have been some fourty(40) times higher in the early Archean eon(~400 nM), than it is now(~9 nM), while the concentration of Iron went from somewhere in the 50uM to nM range, a drop of four orders of magnitude from then to now.
The type of alkaline fluid that emanates from the hydrothermal field, and it’s mineralogical composition, is heavily dependent on both the oceanic concentrations and the underlying geology that hosts it.
They are. There isn’t any reason to think there’s something unrealistic about the Nickel content of the precipitate used to create the inorganic barrier.
You did. You ignored the evidence for metabolism-first hypotheses. Completely. You launched a completely groundless attack on the method of a single paper, completely ignoring the evidence, as @Rumraket thoroughly documented.
Building blocks are not the focus of metabolism-first hypotheses. You’re ignoring them; blathering about “building blocks” demonstrates that you obviously lack the most basic understanding of them.
See, you’re again ignoring OOL hypotheses by assuming that cells were the first step. You are obviously working only from IDcreationist hearsay, not evidence.
More of the same. You’re also demonstrating that you don’t understand the difference between scientific hypotheses and theories, SOP for IDcreationists who are only familiar with hearsay.
One painfully obvious reason is because redox conditions were very different then. Life itself changed them. More ignorance.
You haven’t shown that they are not realistic. You’re sneaking your conclusion into your premise.
I don’t see a speck of honesty in your ignorant, arrogant, evidence-free attacks on science.
Apparently not, but he still considers himself sufficiently informed to offer criticism.
I predict that no response is forthcoming.
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BlockquoteFirst of all can you please provide a direct response to my correction of your misapprehension of the use of a 98% pure NiCl2 salt?
I’m sorry I didn’t make my point clearer, it was poorly written. The nickel salt that they added to their experiments represents the amount of nickel that is dissolved in the the ocean. In our modern ocean Ni is present at in incredibly small traces as shown in the link below 2 ppb or less.
So as you correctly pointed out in your post Ni levels were 40 times higher during the Archean Eon than they are today, so about 80 ppb, but in this experiment the researchers pumped 5,000,000 ppb, or said another way a concentration of Ni 62, 500 times higher than would have existed in the Archean ocean, if we assume a primordial ocean wherein the Ni concentration it 40 times the high end of nickel concentrations found naturally in ocean water today.
I understand that the concept of wanting to speed up reactions but why not increase concentrations by 50 times, or even 500 times what would have been found in nature? That would have definitely increased the chances of creating measurable condensates. but that’s not what they did. So I don’t think an. experiment that uses concentrations of Ni 2.5 million times what exists in the ocean today is actually showing us what could have occurred in nature.
That’s not a direct response. It doesn’t address your focus on the purity.
I said it was poorly written, I should have focused on the actual concentrations in the water not the purity of the reagents. One can definitely use pure reagents to make realistic sea water, so it not the reagents is the problem it’s the composition of the solution that isn’t realistic. Which is not how I explained the problem in my earlier post.
Then it wasn’t “poorly written,” it was just plain wrong.
It’s not a problem, because you have no idea what the composition of ancient sea water was, and more importantly, how it varied around the globe.
Meaning your earlier post was just plain wrong. Why all the silly tapdancing?
I’m not tap dancing, the focus on purity was a mistake, but the broader point that the concentrations weren’t realistic is still very relevant. These points are not all or nothing.
Again, you have zero evidentiary basis for claiming anything to be realistic or unrealistic.
It’s almost as ridiculous as your claim that Tour mentioning lipids somehow meant that he had addressed metabolism-first hypotheses.
BlockquoteIt’s not a problem, because you have no idea what the composition of ancient sea water was, and more importantly, how it varied around the globe.
That is a good point, it’s also worth pointing out that I don’t have any vested interest in constraining environmental conditions at the OOL. For example some researchers have pointed to evidence that life may have first appeared on during the Hadean Eon when the global ocean was alkaline. Since I don’t believe that planets create cells anyway, what the specific environment was were it happened isn’t an issue for me. Still what evidence are you aware of that nickel concentrations were 2.5 million times higher during the Hadean? Just the fact that the alkaline vent hypothesis needs such concentrations is evidence of its limitations.
There’s a LOT of ego visible to me.
I doubt that the first life was cellular, so your belief is just vapid.
They didn’t have to be higher everywhere, as @Rumraket clearly explained.
I see no evidence that it needs them.
The fact that you were so unaware of metabolism-first hypotheses that you claimed that Tour’s mentioning lipids somehow addressed them is evidence of your dependence on hearsay and avoidance of evidence.
To be honest I think you actually didn’t understand what the 98% pure salt was used for(you didn’t just write poorly), but I’m glad to see that at least you now understand how pure that salt was when bought isn’t relevant to the experiment they go on to perform.
Because it’s not relevant to the question they are addressing, which isn’t whether an Fe(Ni)S bearing precipitate can form from hadean sea water. But whether a precipitate maintaining a sufficiently steep pH gradient, containing those atoms, can reduce CO2 with H2. That’s the question they seek to address. If you read the paper you’ll see the fluid the use to make the barrier actually also contains silicate.
And your question doesn’t even make sense, as I have a hard time believing you’d not complain if they still used a concentration of Ni 50 or 500 times the average of what it was in archean sea water.
Incidentally we already know serpentinization produces Fe(Ni)S bearing minerals such as mackinawite, and that such minerals are found in hydrothermal systems.
Mackinawite occurs in serpentinized peridotites as a hydrothermal alteration product, in meteorites, and in association with chalcopyrite, cubanite, pentlandite, pyrrhotite, greigite, maucherite, and troilite.[3]
Edit:
Apparently the source of Ni in the Fe(Ni)S minerals isn’t thought to come only from the surrounding ocean, but also the process of serpentinization of Ni-bearing minerals in the underlying geology of the hydrothermal system itself.
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No, I simply knew that most of the Nickel in seawater is already bonded to Hydrogen and so it isn’t available to react with additional H2 released at the vents, That’s why I focused on the percentage Nickel present in rocks as the only source of pure Ni.
However after I read your post I agreed with your point that one could have used pure Ni to make realistic seawater so I wrote as much. There probably were trace amounts of nickle compounds floating in the water not impacting the reaction, so adding more of them would have been pointless. The real problem is the concentration of the pure Ni not the fact that they used it in their solution.
Still there’s has been no evidence presented that the water in the vent had Ni concentrations millions of times what exists today. One way to achieve that effect would be to claim that the rocks were disintegrating at a rate millions of times what happens in alkaline vents today. Of course that would collapse the vent chimney too fast for the OOL hypothesis to work.
Ni in sea water bonded to hydrogen? How did you get that idea? The common ions of both are positively charged. You’re not making any sense here.
The percentage of nickel “present in rocks”, whatever that is supposed to mean, isn’t the only source of “pure Ni” and it isn’t clear why it would need to be pure anyway. The point is that it precipitates out and forms a part of the vent structure on the ocean floor when the venting fluid meets the ocean because it’s solubility is highly sensitive to sudden changes in temperature and pH.
The hypothesis is that the vent chimney, probably mostly made of Silicate or Carbonate rocks, still has inclusions of various types of metal sulfides. The chimney structure provides a barrier that can function as a semi-permeable membrane that allows certain small ions, or an electrical current, to pass through it, such as H+. Protons and electrons. Such that there is a pH (proton) gradient across it. The vent structure is then thought to have inclusions of iron, nickel, and other metal sulfides and minerals. These act as catalysts. Even if the metal concentrations in both the sea water and the hot venting alkaline fluid ultimately are very low, the conditions that occur when these two fluids mix (hot alkaline fluid mixes with colder more acidic sea water), is thought to be conducive to the formation of these minerals. The sudden drop in temperature and pH causes the dissolved minerals to precipitate out and form a structure where the local concentrations in that structure are much higher than it is in the vent fluid.
The oceanic or venting fluid doesn’t need to have millions of times higher concentration for those minerals to precipitate out. All that does is that it affects the rate at which the mineral builds up. At higher concentrations more precipitates out at some given interval of time, so the vent grows faster.
You’re making this much too complicated than it actually is.
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Your right it’s nickle hydrates not hydrides that makes up most of the nickle found in seawater. Hydrides don’t really make sense.