From the UNIVERSITY OF CINCINNATI
Ancient rocks hold evidence for life before oxygen
Somewhere between Earth’s creation and where we are today, scientists have demonstrated that some early life forms existed just fine without any oxygen.
While researchers proclaim the first half of our 4.5 billion-year-old planet’s life as an important time for the development and evolution of early bacteria, evidence for these life forms remains sparse including how they survived at a time when oxygen levels in the atmosphere were less than one-thousandth of one percent of what they are today.
Recent geology research from the University of Cincinnati presents new evidence for bacteria found fossilized in two separate locations in the Northern Cape Province of South Africa.
“These are the oldest reported fossil sulfur bacteria to date,” says Andrew Czaja, UC assistant professor of geology. “And this discovery is helping us reveal a diversity of life and ecosystems that existed just prior to the Great Oxidation Event, a time of major atmospheric evolution.”
The 2.52 billion-year-old sulfur-oxidizing bacteria are described by Czaja as exceptionally large, spherical-shaped, smooth-walled microscopic structures much larger than most modern bacteria, but similar to some modern single-celled organisms that live in deepwater sulfur-rich ocean settings today, where even now there are almost no traces of oxygen.
In his research published in the December issue of the journal Geology of the Geological Society of America, Czaja and his colleagues Nicolas Beukes from the University of Johannesburg and Jeffrey Osterhout, a recently graduated master’s student from UC’s department of geology, reveal samples of bacteria that were abundant in deep water areas of the ocean in a geologic time known as the Neoarchean Eon (2.8 to 2.5 billion years ago).
“These fossils represent the oldest known organisms that lived in a very dark, deep-water environment,” says Czaja. “These bacteria existed two billion years before plants and trees, which evolved about 450 million years ago. We discovered these microfossils preserved in a layer of hard silica-rich rock called chert located within the Kaapvaal craton of South Africa.”
With an atmosphere of much less than one percent oxygen, scientists have presumed that there were things living in deep water in the mud that didn’t need sunlight or oxygen, but Czaja says experts didn’t have any direct evidence for them until now.
Czaja argues that finding rocks this old is rare, so researchers’ understanding of the Neoarchean Eon are based on samples from only a handful of geographic areas, such as this region of South Africa and another in Western Australia.
According to Czaja, scientists through the years have theorized that South Africa and Western Australia were once part of an ancient supercontinent called Vaalbara, before a shifting and upending of tectonic plates split them during a major change in the Earth’s surface.
Based on radiometric dating and geochemical isotope analysis, Czaja characterizes his fossils as having formed in this early Vaalbara supercontinent in an ancient deep seabed containing sulfate from continental rock. According to this dating, Czaja’s fossil bacteria were also thriving just before the era when other shallow-water bacteria began creating more and more oxygen as a byproduct of photosynthesis.
“We refer to this period as the Great Oxidation Event that took place 2.4 to 2.2 billion years ago,” says Czaja.
Early recycling
Czaja’s fossils show the Neoarchean bacteria in plentiful numbers while living deep in the sediment. He contends that these early bacteria were busy ingesting volcanic hydrogen sulfide — the molecule known to give off a rotten egg smell — then emitting sulfate, a gas that has no smell. He says this is the same process that goes on today as modern bacteria recycle decaying organic matter into minerals and gases.
“The waste product from one [bacteria] was food for the other,” adds Czaja.
“While I can’t claim that these early bacteria are the same ones we have today, we surmise that they may have been doing the same thing as some of our current bacteria,” says Czaja. “These early bacteria likely consumed the molecules dissolved from sulfur-rich minerals that came from land rocks that had eroded and washed out to sea, or from the volcanic remains on the ocean’s floor.
There is an ongoing debate about when sulfur-oxidizing bacteria arose and how that fits into the earth’s evolution of life, Czaja adds. “But these fossils tell us that sulfur-oxidizing bacteria were there 2.52 billion years ago, and they were doing something remarkable.”
###
FUNDING
This work was supported by the National Geographic Society-Waitt Grant Program and the NASA Astrobiology Institute.
Czaja’s paper, “Sulfur-oxidizing bacteria prior to the Great Oxidation Event from the 2.52 Ga Gamohaan Formation of South Africa,” was published in Geology, a journal of the Geological Society of America.
That fossil is about 0.2mm across. Can someone explain – how do they know this is a fossil of a bacteria, and not just a mineral deposit that looks like that ? Fossils of complex life are obvious – but what is it about microscopic fossils like these that prove they are from bacteria and not just a random mineral formation ?
I don’t think that’s millimeters
OK, I see it now.
I always thought that it was well known that all of earth’s oxygen was produced by pre-oxygen creatures; some sort of blue green algae; unless that’s a different story.
So if that is true, then it stands to reason that there was some life before oxygen.
Please send grant funds, so I can list some other things we already know.
G
The micrometre (International spelling as used by the International Bureau of Weights and Measures;[1] SI symbol: μm) or micrometer (American spelling), also commonly known as a micron, is an SI derived unit of length equaling 1×10−6 of a metre (SI standard prefix “micro-” = 10−6); that is, one millionth of a metre (or one thousandth of a millimetre, 0.001 mm, or about 0.000039 inch).[1] The symbol μm is sometimes rendered as um if the symbol μ cannot be used, or if the writer is not aware of the distinction.[citation needed]
The micrometre is a common unit of measurement for wavelengths of infrared radiation as well as sizes of biological cells and bacteria and is also commonly used in plastics manufacturing.[1] Micrometres are the standard for grading wool by the diameter of the fibres; wool finer than 25 μm can be used for garments, while coarser grades are used for outerwear, rugs, and carpets.[2] The width of a single human hair ranges from approximately 10 to 200 μm. The first and longest human chromosome is 10μm in length.
Stewart Pid, good to see you here. I usually encounter you jousting with that verbal diarrhea artist JC on the Weather network garbage.
Actually it is 0.00003937 inch.
G
PS: it is NOT 10,000 Angstrom Units.
George, I’m not so sure. The next major unit downward is the nanometer (10^-9 meter) which is a factor of a thousand smaller than a micron, and the Angstrom unit is a tenth of a nanometer. So, by this accounting, 1 micron = 10,000 A.
“Fossils of complex life are obvious”
Some more info here
Microscopic life forms are pretty complex too.
I wonder the same thing gzk. What is the resolution of the medium that the fossil is in. How can the fossil contain any detail of the ‘complex’ nature of the bacteria?
I am no micro fossil expert, but this kind of seems like confirmation bias. People seeing what they want to see. Maybe I’m crazy.
Yes Jeff – that’s exactly what I thought. I hope I’m wrong, and I’d like to see some good detail on exactly how they managed to determine those structures are biological in origin and not mineral. There probably is a good, detailed answer, which I hope someone can explain.
Haven’t read the article, but the press release says the fossils were found in chert. Chert is a glass-like silica mineral that can sometimes preserve very fine detail of organic structures in the beds where it forms — cell walls, cell nuclei, other internal structures of ancient lifeforms. A substantial percentage of our (quite skimpy actually) detailed knowledge of vary ancient life comes from fossils preserved in chert. Here’s a link to the Wikipedia article https://en.wikipedia.org/wiki/Chert. Caveat — Paleontology papers often include large amounts of conjecture. Sometimes it is later substantiated. Sometimes it doesn’t stand up to scrutiny. However, paleontologists seem much less prone to call folks names when their assumptions are questioned than, for example, climate scientists.
According to the scale bar on the lower right, that feature is about 200 micrometers in diameter = 0.2 mm. That is huge for a bacterium. The usual modern bacterium is about 0.5 micrometer diameter, or 400x smaller than the pictured feature. The typical cell from a modern advanced organism is about 10 micrometers diameter, some 20-times smaller than the pictured.
It’s hard to imagine a bacterium that big.
A couple of other questions. What was that bacterium using as an oxidation source? If it’s oxidizing H2S to produce sulfate, it needs an oxidant. What is that oxidant in an anoxic (oxygen-free) environment? In ancient days, the terrestrial surface was loaded with reduced iron. There wouldn’t have been much free nitrate (a candidate for terminal metabolic oxidant).
Second, typically, anaerobic bacteria are sulfate-reducing. That is, they use sulfate as their terminal oxidant and produce H2S as a waste product — the oppositely directed metabolism of what they are saying here for that ancient bacterial metabolism.
Finally, “then emitting sulfate, a gas that has no smell.” Sulfate is not a gas. It’s a doubly charged anion.
Remember, though, oxidation doesn’t necessarily need oxygen. Chemists have decided to use “oxidation” and “reduction” to refer to a broad range of reactions where electrons are transferred. So any time you hook up a battery to a circuit, you’re causing an oxidation reaction to take place, and most of those don’t depend on oxygen in the system.
Pat Frank,
Yes, it’s big for a bacterium. But consider how large some eukaryotic unicellular organisms can grow.
https://www.sciencedaily.com/releases/2015/01/150129160728.htm
Summary: Biologists used the world’s largest single-celled organism, an aquatic alga called Caulerpa taxifolia, to study the nature of structure and form in plants. It is a single cell that can grow to a length of six to twelve inches.
Karllembke, I am a chemist and I understand all of that. They need a terminal metabolic oxidant. Apparently they chose nitrate. It’s hard to believe terminal nitrate for an ancient anoxic earth full of reduced iron. I’d have guessed sulfate as a terminal oxidant in ancient anaerobes, but the paper doesn’t allow that.
Chimp, bacteria are prokaryotes. I didn’t know any that get larger than 1 micron.
However, I’ve now searched “giant bacteria” in Google Scholar, and found a 2007 Nature paper that described “Thiomargarita”, a sulfur oxidizing bacterium which “is currently the largest known bacterium, with average cell diameters between 100 and 400 μm (some cells grow as large as 750 μm)…” The scale bar on this image of Thiomargarita (left) is 100 microns.
So, apparently a 200 μm bacterial fossil is not unreasonable.
Pat Frank
November 30, 2016 at 3:23 pm
Of course they’re prokaryotes. My point is that viruses are mostly smaller than prokaryotes (bacteria and archaea), while prokaryotes are smaller than eukaryotes. You’re right about the normal range of prokaryotes, but quite a few are giant, like Thiomargarita, about which I commented previously.
Until the discovery of Gram-negative Thiomargarita namibiensis in 1999, Epulopiscium fishelsoni (“epulo” for short) was the largest known bacterium. It’s a Gram-positive bacterial symbiont of surgeonfish. The species ranges from 200 to 700 μm in length.
Well ordinary minerals just don’t show any grain boundaries; only biologiums can have structure.
g
Yup. The fossil is clearly not a geologic structure in the chert, but biological in origin.
The definition of chert is “a fine-grained silica-rich microcrystalline or cryptocrystalline sedimentary rock that may contain small fossils”. It is also described as “a hard, dark, opaque rock composed of silica (chalcedony) with an amorphous or microscopically fine-grained texture, (which) occurs as nodules (flint) or, less often, in massive beds”.
At least NASA are spending some money on actual research !
Yeah, it is called ANAEROBIC.
https://en.wikipedia.org/wiki/Anaerobic_organism
it would be interesting if they could find an anaerobic method based on these pre oxygen life forms to propel space craft. Could open up low weight fuels. Refueling stations on asteroids and the like.
We might not need “fuel” at all. Just a source of electricity.
http://newatlas.com/cannae-reactionless-drive-space-propulsion/33210/
The problem is not fuel. It is that space propulsion work by utilizing Newton’s Third Law, for every action there is an equal and opposite reaction. (I can’t show the math because I don’t know how to do subscripts in this format). Ultimately, you must throw a lot of mass out the back in order to move at any reasonable speed.
This constraint holds even when you use so called ion engines that use electricity, which may be generated by solar panels or nuclear methods, to accelerate ions of some type such as Cs or Xe.
As for “reactionless” drives. No one has built one yet. And there is no theory of why one should work at all.
The faster you throw the stuff out the back, the less stuff you need to throw.
Supposedly the Cannae Drive does violates this principle. I suspect it in fact does not violate the principle but works in a manner in accordance with it, or derives its forces (thrusts) from electromagnetic methods. NASA is still testing this device to determine how it provides the small thrusts it does. It very well may turn out that it only works in the presence of a magnetic field or that it will be due to an experimental measurement error much like the vaunted “Cold Fusion”. Time an replication will tell. That’s what we call real science: Guess and test, and test, and test….
Also Walter, the rocket propulsion is a consequence of conservation of momentum. (p=mv)
Nobody ever gives a damn about the energy. (E=(1/2)mv^2).
Guess where virtually all of the energy goes in an ion rocket.
G
No problem finding systems to propel you once you are out of a gravity well like Earth or Mars.
Getting out of the well is the problem.
That’s why with current technology getting to the surface of Mars is not much of a problem.
Getting off the surface is another story.
At the moment for a manned [humanned /peopled?] mission it’s a one way trip
The main problem, at least in life forms, is that metabolic reactions that don’t use oxygen are not terribly efficient. I think anaerobic metabolism of glucose yields some four molecules of ATP converted from ADP. The citric acid cycle, which needs oxygen to run, converts 16 ADP into ATP, meaning four times as much energy is available from the same amount of fuel oxidized.
(If I were home, I could crack open a book. Or if I cared to spend the time on Wikipedia, I could maybe verify the numbers, and even pull up the name of the anaerobic pathway which I’m blanking on.)
karllembke
November 30, 2016 at 12:10 pm
Which is why multicellular life awaited a more oxygen-enriched environment, and the pace of evolution accelerated with even more molecular oxygen available.
To the anaerobes living over two billion years ago, oxygenation of the earth was initially a catastrophe, leading to poisoning of their environments and mass extinction. But eventually life recovered and went on to evolve greater complexity, leading to multicellular eukaryotes, ie fungi, animals and plants.
so the asteroids are off limits for strip mining too. leave it in the ground.
The deep oceans still teem with life that requires neither oxygen or sunlight. link Considering the strange biological communities that live in the vicinity of hydrothermal vents, it unsurprising that life evolved before atmospheric oxygen. link
If I recall correctly, the relatively high levels of oxygen in the atmosphere is due to the development of photosynthesis as a metabolic process.
Yes, and to this day, most oxygen arises from single cell organsims. Which by Occam’s Razor, most carbon sink potential is by single cell photosynthesis.
Why all the tree worship in CAGW acolyte circles?
…so it is unsurprising life evolved before atmospheric oxygen.
What is surprising? That many people thought all life depends on oxygen.
But I wonder about this. From a certain point of view, the oxygen created from photosynthesis is also consumed by metabolism, so how much extra can there be? One might suppose that the net addition of oxygen corresponding to the production of a plant’s cellular matter from CO2 and H2O, and that would be it. The rest is an endless cycle. (Growth of plant balanced by decay of dead plant?)
Now, it turns out that water is quite easily dissociated by UV radiation, forming O2, OH, H2 and so forth. This process should be occurring when the levels of oxygen are low. When oxygen rises, it absorbs UV and forms ozone, which absorbs more UV, shutting down the UV-hydrolysis process. To what extent did this mechanism operate to transform the chemistry of our atmosphere? If it did operate, what does that imply about the length of time for the process to occur?
Michael,
Bear in mind that it took a good while for unicellular eukaryotes and their fungal and animal descendants to evolve to metabolize the free oxygen.
The first were cyanobacteria (blue/green algae) that formed clumpy coral like heads along the coastlines spewing out poisonous oxygen! I suppose if any environmentalists existed then we might call them blues or aquas, and they would be all enraged by the O2 pollution.
Oxygen in the atmosphere would have prevented life from evolving on earth.
G
George,
Even today there are plenty of anoxic environments in which anaerobic life could have arisen and evolved. There would have been more when O2 levels were much lower, as they remained for over a billion years after the Great Oxygenation Event/Catastrophe.
Oh, bosh. If there were no oxygen in the atmosphere, there would be nothing to prevent UV from shining directly on water and generating oxygen from the splitting of the water molecules.
You can made sulfate from hydrogen sulfide oxidizing by (gaseus) oxygen. What those bacteria is claimed to use? And the reagent is not oxidizing by oxygen?
There are bacteria that use sulphide and produce sulphate and bacteria that do it back. But you can’t make free energy both ways.
It would be interesting to see whole cycles.
Sorry my typos. To make sulfate from sufide you need some more powerful oxidizer than sulfate, like hydrogen peroxide. But how you get that in oxygen defiency environment? Bacteria use only existing chemical potential.
How do cyanobacteria generate O2 from H2O and CO2? Same problem.
Hydrogen peroxide is the main reaction product of ionizing radiation passing through water. It has been identified since the 70s or earlier as the mechanism for biological damage resulting from radiation exposure.
This is my problem too. How can you oxidise without access to oxygen?
Are they also generating – say – methane by stripping oxygen out of CO2 and water?
Oxygen was plentiful in the microbes’ environment. It just wasn’t gaseous O2, but bound up in H2O and other compounds.
Photosynthesizing organisms use H2O and CO2 to make sugar, releasing gaseous molecular oxygen in the process. The oxygen they produce and release into the air comes from water rather than carbon dioxide. So there is a similar step in the processes of sulfur-oxidizing bacteria.
Oxygen need not be molecular. Many minerals are oxides. I believe that there would be many sources of oxygen available. The cosmos is the source of almost all the elements in the periodic table. One can therefore conclude, based on this theory, that the earth contains nearly the same quantity of heavy elements as it did 2.5 billion years ago.
Mr. Layman here (with a water/wastewater treatment background).
An anaerobic organism still requires oxygen but obtains it from its food. Dissolved oxygen can kill it.
A facultative organism requires oxygen but can obtain it from its food or its environment.
An aerobic organism can only obtain its oxygen from its environment.
Chimp November 30, 2016 at 10:59 am
The hydrogen to oxygen ratio of the end products of photosynthesis is identical to that of water. The carbon to oxygen ratio is contrary to that of CO2. This makes it appear that the entire water molecule is put to use, while only the carbon is retained from CO2.
Do you know of any testing to verify which oxygen gets released? Perhaps water containing only O18 could be used to grow something and then the O2 released could be captured and tested.
SR
Stevan,
We know the source of the O2 released during photosynthesis because we now understand in some detail the whole complicated process, both its light and dark reactions. During photosynthesis, oxygen is produced from the photolysis of water, which occurs when light is used to split water into hydrogen (electrons and protons) and oxygen.
Photosystem II (PS II) is an extremely complex, highly organized transmembrane structure within photosynthetic chloroplasts that contains a reaction center (P680), a water-splitting complex, chlorophylls and carotenoid pigments, pheophytin (a pigment similar to chlorophyll), and two quinones. PS II uses the energy of sunlight to transfer electrons from water to a mobile electron carrier in the membrane called plastoquinone.
The step H2O → P680 is performed by the water-splitting complex (also called the oxygen-evolving complex), a poorly understood structure embedded within PS II. The complex catalyzes a reaction that splits water into electrons, protons and oxygen: 2H2O → 4H+ + 4e− + O2.
The electrons are transferred to special chlorophyll molecules (embedded in PS II) that are promoted to a higher energy state by the energy of photons.
Hope this helps.
Chimp November 30, 2016 at 10:59 am
Oxygen was plentiful in the microbes’ environment. It just wasn’t gaseous O2, but bound up in H2O and other compounds.
Photosynthesizing organisms use H2O and CO2 to make sugar, releasing gaseous molecular oxygen in the process. The oxygen they produce and release into the air comes from water rather than carbon dioxide
===============
Chimp, your reply at 4:14 pm does not address the subject of my response at 3:47, where I questioned your claim that the O separated from H2O was released to the atmosphere in the photosynthesis sugar making process. Going into detail on the photolysis part does not speak to whether that oxygen was released, or incorporated into sugar during the synthesis part of photosynthesis.
SR
The oxygen that’s released into the atmosphere from photosynthesis comes from water molecules.
Stevan,
The O2 freed from H20 is indeed released as a waste byproduct of photosynthesis.
All the oxygen in sugar comes from CO2 in a number of steps, in this overall balanced equation, starting with six carbon dioxide molecules and six water molecules, in which a molecule of glucose (C6H12O6) and six diatomic oxygen molecules (derived from H20) result:
6CO2 + 6H2O —-sunlight energy—> C6H12O6 + 6O2.
I could explain every step in the manufacture of sugar in chloroplasts from water, carbon dioxide and the energy of photons, but this cartoonish site IMO provides enough detail:
http://www.howplantswork.com/2009/02/16/plants-dont-convert-co2-into-o2/
Hope it helps.
Stevan,
This site goes into more detail. Please go to the section on the dark reactions (light-independent) to see how hydrogen (separated from oxygen) is attached to carbon dioxide molecules to make glucose:
http://www.rsc.org/Education/Teachers/Resources/cfb/Photosynthesis.htm
I’d copy and paste the section, but dunno if the diagrams would show up.
The short version is that photosynthesis uses light energy to split H from H20 and attaches an H atoms thus derived onto CO2 molecules to make the sugar (carbohydrate) glucose and oxygen molecules composed of atoms which previously were bound with hydrogen in water.
Chimp December 2, 2016 at 11:42 am:
6CO2 + 6H2O —-sunlight energy—> C6H12O6 + 6O2
It is not possible to release 6 O2 molecules from just 6 H2O molecules. Even if every O derived from water was released, 6 more Os from the CO2 would also have to be released. Nothing you have posted supports your claim that the released O2 does not come from the CO2, but from the H2O.
SR
karllembke December 2, 2016 at 11:59 am
Thank you for info that actually addresses the subject under discussion. I looked into the experiments by Samuel Ruben and Martin Kamen, and at first glance their data does seem to support the concept that all released O originated with water molecules.
However, their experiments do not explain how the 6 oxygen atoms bonded to Hydrogen on the left side of this equation could provide the 12 oxygen atoms on the right side released as O2:
6CO2 + 6H2O —-sunlight energy—> C6H12O6 + 6O2
SR
Stevan,
Everything I have said supports the fact that the O2 released into the water or air during photosynthesis comes from water, as do the links I provided.
The first link answered your question about isotopic experiments. In 1941, Ruben, et al. used heavy oxygen (18O) to find out where the oxygen atoms went in photosynthesis. They fed plants water containing 18O, but because it is not a radioactive isotope of the most common form of oxygen, 16O, they relied on a mass spectrometer to determine the fate of the 18O. The 18O was found in the oxygen gas produced by the plant, but was not found in the sugars formed during photosynthesis.
This and other scientific experiments have provided clear evidence that the oxygen produced by photosynthesis is derived from water.
Melvin Calvin conducted experiments such as you suggested, using a radioactive isotopic tracer (14C) to work out how photosynthesis happens. He won the Nobel Prize for his experiments. The Calvin Cycle is named in his honor. He too discovered that the O2 released during photosynthesis comes from water alone.
http://www.globalchange.umich.edu/globalchange1/current/lectures/kling/energyflow/PSN_primer.html
While it’s a complex series of steps, what basically happens in photosynthesis (details in the links I provided) is that in a light reaction, energy from the sun splits two hydrogen atoms from the oxygen atom in water molecules. The oxygen atom thus liberated combines with another free oxygen atom to form a diatomic O2 molecule and is expelled as waste from the chloroplast.
In the dark reactions, two things happen (in a long series of complex steps). One is that six CO2 molecules are joined together, and the other is that two hydrogen atoms are attached to each of the carbon dioxide molecules in this chain. This new, large molecule of glucose thus has six carbon atoms and six oxygen atoms from six CO2 molecules and 12 hydrogen atoms from six water molecules, with diatomic oxygen molecules left over from split water molecules.
I can see why you think that the equation doesn’t balance, since the oxygen molecules don’t add up based upon water alone, assuming equal numbers of starting water and carbon dioxide molecules. But in the real world, plants have unequal numbers of the two molecules than go into making glucose. So the fact is that the oxygen in CO2 stays with the carbon atoms in sugar, while the oxygen atoms from water are expelled. Photosynthesis is not an efficient process.
I read the abstract:
http://geology.gsapubs.org/content/44/12/983.abstract
They compare their bacteria to Thiomargarita:
https://en.wikipedia.org/wiki/Thiomargarita_namibiensis
It seems that nitrate is nitrate for Thiomargarita.
Is there any plausible way make nitrate without oxygen in atmosphere? Can those researchers tell or may they need study more chemistry?
Sorry It seems that nitrate is nitrate = It seems that oxidizer is nitrate
NO-3 = Nitrate. 3 oxygen atoms to each nitrogen
broken down to many other nitrous/nitric and oxygen compounds
Thiomargarita namibiensis is a gram-negative coccoid Proteobacterium, found in the ocean sediments of the continental shelf of Namibia. It is the largest bacterium ever discovered, as a rule 0.1–0.3 mm (100–300 µm) in diameter, but sometimes attaining 0.75 mm (750 µm).
The largest known virus is Megavirus chilensis, with a capsid diameter of 440 nm and hair cover of 75 nm. (A nanometer is 1/1000 of a micron or µm.)
Sulfate isn’t a gas, it’s an anion.
So the largest known virus is Megavirus chilensis, but it hasn’t been discovered yet. The largest one that HAS been discovered is Thiomargarita namibiensis, which uses sulfur instead of NaCl around the rim of the glass. Tastes and smells like rotten eggs.
g
Megavirus is a virus, and it has been discovered. I’ve seen it myself.
Thiomargarita is not a virus. It’s a very large bacterium. Bacteria are usually much larger than viruses, although they do overlap in size at the high and low ends.
Quite correct. I find it difficult to understand where the oxygen needed to oxidize sulfide to sulfate is coming from, given that these bacteria were living in an anaerobic environment.
Oxygen was a waste product of these organisms. We are thriving in their ‘pollution.’
Not only that but oxygen is a highly corrosive gas. If there had been an environmentalist movement, they would have worked for a treaty banning oxygen.
We wouldn’t even be here if there had been oxygen in the atmosphere.
G
Gee, George…Were you there to see it not happen? Let up on the dogma.
Probably from the water contained the rock layers they lived in.
H2O
The oxygen came from water. Even today underwater geothermal vents release tremendous amounts of sulfides into the sea, which these bacteria consume.
Don’t confuse atmospheric or dissolved free oxygen with oxygen containing compounds like water. The biochemistry of anerobic bacteria is complex. But only an energy source (including from chemical potential) is needed. The rest is enzymes.
It is a tiny rock, the same size as some strange things alive today. No evidence that it was ever alive.
Goodness, the state of academia today…
Just because you are unaware of particular analytical methods does not mean they don’t exist
level 1 expert – knows it without studying
level 2 expert – has studied the issue, does not know it all
level 4 expert – has been doing related work and knows what is unknown
level 5 – emeritus, knows it from old books, should study, could learn new things
Hey Alex,
I have a great deal on some fossilized bacteria for you, how many would you like?
Michael Moon,
There is abundant evidence that it was alive. Why would you make that false assertion without reading the paper? Its full text is free:
http://geology.gsapubs.org/content/44/12/983.full
No there isn’t. A little round rock could have been formed many, many ways, Credulous Chimp.
Obviously life existed before oxygen. Just where do they think the oxygen came from?
No one knows. No one knows where things started. It’s not possible.
Why do you claim things started? You don’t know if existence should be time-dependent.
Anyway, we do know first life forms at the Earth could not depend on free oxygen.
Hugs—I don’t know if existence should be time-dependent, no. Nor do I claim that. Allow me to rephrase:
No one knows when things started or if things started at all. Our understanding of time is limited and time may work in ways we don’t understand. There could have always been “something” and thus no start. Time may not apply to everything. In other words, we really don’t know much.
I would disagree that the first life forms on Earth could not depend on free oxygen. Again, we can’t know that. We think it’s true and seems logical to many at this point.
Reality check,
We do know where the oxygen came from, and that life arose or arrived on earth in environments practically free of gaseous, molecular oxygen, ie O2. Of course there was lots of oxygen, but it was bound up in compounds with hydrogen, nitrogen, sulfur and carbon, etc.
Photosynthesizing organisms like cyanobacteria evolved and released this oxygen as molecular gas. At first iron absorbed the free oxygen by rusting, creating the red bands found around the earth in rocks of the right age. Then it got released into the atmosphere, causing the Great Oxygen Catastrophe, which poisoned many of the organisms living at that time.
I would simply point out that oxygen compounds with hydrogen, nitrogen, and carbon are very chemically active. Some of them (e.g., nitrates, chlorates, sulfates) are oxidizers of a most literal variety (at least, that’s the way they work in rocket propellants). Some insects synthesize hydrogen peroxide within themselves.
Oxygen compounds with metals (mineral oxides) are much harder to dissociate.
Star dust is the stuff from which EVERYTHING exists.
Free oxygen atoms exist in space. It’s merely that the valence of oxygen provides a very strong connections with most other atoms it encounters so we find that much of the O2 has already combined with a willing neighbor.
The Kaapvaal Craton is also home to the huge Vredefort impact structure.
Interesting, but little more than an unprovable theory about something we can never know.
Reality check,
This discovery is not an “unprovable theory”. It’s some observations, the most convincing explanation for which is that the structures are fossil sulfur-oxidizing bacteria.
I’d urge you to read the paper to find all the evidence in favor of this interpretation of the observations.
“It’s some observations, the most convincing explanation for which is that the structures are fossil sulfur-oxidizing bacteria.”
It’s some imaginings, like the rest of Evolution Siants . . I’m convinced ; )
John Knight,
It’s not imaginings. It’s observations and deduction therefrom, leading to testable, falsifiable predictions, ie science.
On what basis are you convinced that evolution isn’t a fact, besides the falsehoods of your cult? How do you feel about the theory of universal gravitation, the oxygen theory of combustion, the atomic theory of matter, the germ theory of disease, the theories of relativity and quantum mechanics? All the same as the theory of evolution, scientific facts, ie observations, with a body of theory explaining them.
Chimp,
“On what basis are you convinced that evolution isn’t a fact…”
The term ‘evolution’ just means change over time . . which (in dork-speak ; ) I consider to be “a fact”. What I was referring to is the imaginary stuff, like imagining amphibians gradually turning into reptiles, which obviously has only been imagined, not observed. Which doesn’t mean (necessarily, to me) that it didn’t happen, just that it hasn’t been observed. As in, it ain’t science.
Chimp, I’ve had that conversation, and you’re not going to get very far. 🙂
You’re dead-on right, though. The earliest evidence for the emergence of life dates back to a couple of hundred million years after the end of the Hadean, about 3.8 billion years ago. Well-preserved bacterial fossils are dated back to nearly 3.5 billion years ago, and were already evolutionarily advanced.
For example, “[T]he earliest isotopic indications of the existence of organisms fractionating carbon in ∼3.8 Ga rocks from the Isua greenstone belt in Greenland are tenuous. Well-preserved microfossils and microbial mats (in the form of tabular and domical stromatolites) occur in 3.5–3.3 Ga, Early Archaean, sedimentary formations from the Barberton (South Africa) and Pilbara (Australia) greenstone belts. They document life forms that show a relatively advanced level of evolution.” quote taken from F. Westall Early Life on Earth: The Ancient Fossil Record in “Astrobiology: Future Perspectives” P. Ehrenfreund, et al., eds, Kluwer 2005.
John Knight,
Of course “amphibians” evolving into “reptiles” has been observed. It’s not imaginary, but a fact, supported by all available evidence.
The transition from “amphibian” tetrapods dependent upon water, or at least very moist environments, to reproduce into amniotes which lay shelled eggs, permitting the colonization of drier habitats, is visible in the Carboniferous Period fossil record, in embryological development, in the anatomy, genomes and biochemistry of animals alive today and in every other relevant line of evidence.
There is no evidence whatsoever against the observation, ie fact, that tetrapods evolved into amniotes.
As I said, all you have against this scientific fact is the preaching of your false cult. In the Bible, the earth is immobile and flat, with four corners in some passages but possibly a disk in others, with the sun moving over it through doors, with a solid vault over it, from which hang the stars, with windows through which rain and snow fall from their storehouses, the levers of which are operated personally by God, Who walks on the vault or dome. It is an entirely pre-scientific assemblage of documents, even in the New Testament, which is remarkable, given how far advanced pagan science was in the first and second centuries AD.
Pat,
We now have evidence of life from the Late Hadean in zircons 4.1 billion years old:
http://www.sciencemag.org/news/2015/10/scientists-may-have-found-earliest-evidence-life-earth
I know that creationists are impervious to reality, reason and evidence, but in the interest of upholding the scientific integrity of this blog, I’ll persist in trying to educate them. Otherwise climate alarmists can more easily make their case that skeptics also doubt the fact of evolution.
“Of course “amphibians” evolving into “reptiles” has been observed.”
Only in people’s imaginations, not in the space-time continuum . . obviously.
I fear for my civilization . .
John,
Yes, it has been observed. You don’t need a human to be present at the time an event happened for it to be observed. Astronomers look back in time all the time. You don’t need to witness a car wreck to infer what happened. A sonar operator doesn’t need to see an enemy sub to know it’s there. Copernicus had not observed the earth going around the sun when he correctly inferred that it does so.
The transition you cite is an unavoidable inference based upon all possible evidence, and the total lack of any evidence against it.
It might help if you had ever bothered to study the topics upon which you deem yourself qualified to comment. The transition from tetrapod to amniote is well recorded in Carboniferous rocks, for starters. It is best observed in fossils from Nova Scotia and old Scotland, then conjoined in the minor supercontinent Euramerica.
Only misguided religious prejudice against reality can convince a person that all the scientific evidence and observation in the world is somehow wrong.
Chimp November 30, 2016 at 3:45 pm
John Knight,
Of course “amphibians” evolving into “reptiles” has been observed. It’s not imaginary, but a fact, supported by all available evidence.
=================
Chimp, a curious fact about amphibians is that none extant have scales, while all reptiles do (including turtles). Amphibians are presumed to have evolved from bony fish, which have always had scales. The evolutionary scenario is:
bony fish (always scaled ) –>amphibians (now scaleless)–>reptiles(always scaled)
Three possibilities present themselves:
1. Amphibians lost their scales, then early reptiles re-evolved scales. This raises question of co-evolution.
2. Early amphibians retained scales, reptiles evolved from scaled amphibians, then amphibians lost scales. This raises question of why amphibians all lost scales when no fishes have, even those sharing amphibian’s habitat.
3. At the beginning, scaleless and bony fishes existed, scaleless and scaled amphibians existed, scaled reptiles existed. (Nothing can be said about the possibility of scaleless reptiles)
#1 has serious difficulties.
If there were fossils of early scaled amphibians perhaps we could safely select #2.
There are such fossils: https://en.wikipedia.org/wiki/Temnospondyli
BUT…”Experts disagree over whether temnospondyls were ancestral to modern amphibians (frogs, salamanders, and caecilians), or whether the whole group died out without leaving any descendants.”
So, Chimp, it is not the case that, as you say “Of course “amphibians” evolving into “reptiles” has been observed. It’s not imaginary, but a fact, supported by all available evidence.”
There is evidence available that does not support that evolutionary hypothesis.
# 3 is also supported by available evidence.
It seems that creatures exhibit all sorts of characteristics that vary along a spectrum. Many attempts have been made to establish a temporal sequence, and as many changes in that order have been made, because the past is not observable, nor testable. I can speculate that marine mammals evolved this way: mink -> otter -> seal -> walrus -> narwhal. This type of speculation is all cladistics is.
Chimp, your statement “There is no evidence whatsoever against the observation, ie fact, that tetrapods evolved into amniotes” is not only proven wrong, the statement itself is a bogus argument because no hypothesis stands on the basis of a lack of negative evidence.
SR
Chimp, at 3:45 PM
This thread is too bulky to navigate, so I will make some short remarks.
“In the Bible,” what you say is complete nonsense…and you know it. I am speaking as a 40-year specialist in aerospace engineering. Very interesting passage from Job 26:7, “He stretches out the north over empty space. He hangs the earth on nothing.” This is a glimpse of our present understanding of Earth as a complete body in space, supported on nothing, hanging as so to rotate, the north pole over a desolation. Very surprising to find this in literature that was embedded in an ambient culture of a static cosmogony.
Essentially, all of modern science has been the product of Christian investigators, and whoever was not Christian was at least Jewish. Just read the list of names.
You fancy yourself an expert, but I wonder if you are acquainted with an understanding of stochastic thermodynamics, which pretty much rules out spontaneous generation of order. The Darwinian process boils down to the dual propositions that (a) mutation by radiation damage (b) confers a fully-effective biological advantage that exceeds the differences of natural variation. Not credible on its face. Radiation damage has never been shown to be a blessing (unless you are willing to accept the hormesis hypothesis). Changes smaller than natural “noise” are not noticeable as a signal and will make no difference to the life of the organism. It is communication theory, and genetics is all about communication.
There are other forms of evolution, such as Lamarckian, which involve the idea of accumulated “learning” through generational experience. I’m not a defender, but the point is that Darwinism is not “evolution,” any more than a Ford is all automobiles.
Stevan Reddish
November 30, 2016 at 6:22 pm
You could not possibly be more wrong. You are wrong in every detail, so naturally in your completely unsupported conclusion.
Perhaps you don’t know what the English word “scale” means when applied to fish as opposed to reptiles. The scales of fish are not biochemically the same as the scales of reptiles. The skin of reptiles evolved in response to the arid environments of land. The scales or scutes of reptiles (and bird feathers) are made of alpha and beta keratin, and are formed from the epidermis, contrary to fish, in which the scales are formed from the dermis.
Here are the actual evolutionary relationships among the mammalian groups you mentioned. Mink and otters are closely related members of the Family Mustelidae in the Suborder Caniformia (dog, bear, mustelid and pinniped line as opposed to cat/hyena line) of the Order Carnivora. Seals (both eared and earless) and walrus are members of the same suborder and order, but in the clade Pinnipedia, which includes the Superfamilies Otarioidea (walrus, fur seals and sea lions) and Phocoidea (true seals, ie earless). Narwhals however are members of the Infraorder Cetacea of the Order Artiodactyla (including ruminants), and as such only very distantly related to the Carnivora. Not only anatomy but genetics show these relationships.
There is no evidence whatsoever in favor of creationism and all the evidence in the world, from every possible source, in support of the observed fact of evolution.
Chimp November 30, 2016 at 3:50 pm
….Otherwise climate alarmists can more easily make their case that skeptics also doubt the fact of evolution.
And also:
“Only misguided religious prejudice against reality can convince a person that all the scientific evidence and observation in the world is somehow wrong.”
===========
Chimp, You argue for evolution in the same way as alarmists argue for CAGW.
SR
Michael J. Dunn
November 30, 2016 at 6:40 pm
Clearly you have not studied modern biblical scholarship. The passage from Job which you cite has been elucidated by the discovery of the Ugaritic texts. The “north” to which you refer is actually Mount Zaphon, modern Jebel Aqra, which lies at the northern end of the Levant coast. It is opposed in the OT to Mt. Zion in the southern Levant, ie Palestine.
I know perfectly well that every statement I made about the literal text of the Bible is correct. Your aerospace background is neither here nor there.
Same goes for biology, which just as clearly you have never studied. Modern evolutionary theory is neither exclusively Darwinian nor Lamarckian. It is simply based upon observations of reality. Darwinian evolution is an easily demonstrable fact. Natural and sexual selection indubitably occur, but there are other evolutionary processes that Darwin and Wallace couldn’t have discovered because they didn’t know how inheritance works. Much evolution is not “directional”, ie darwinian under selection, but “stochastic”, ie resulting from statistical processes such as reproductive isolation, genetic drift, the founder’s principle, etc. Modern evodevo theory can be seen as in some sense “Lamarckian”, but again, far removed from Lamarck’s incorrect conjectures.
It never ceases to amaze me that people without any education in, experience with or understanding of biology feel fit to comment thereupon. I don’t presume to comment on aerospace engineering. Please refrain from commenting out of total ignorance on biology until you have at least taken an undergrad degree in the subject. Otherwise you simply make a laughingstock of yourself. Same goes for biblical commentary. (My undergrad minor was in classical languages, so I’ve studied the NT in Greek and learned Hebrew as a lad, so have also read the OT in the original.) Thanks.
“There is no evidence whatsoever in favor of creationism…”
Of course there is, it’s called genetic coding.
JohnKnight
November 30, 2016 at 7:11 pm
The genetic code is unambiguous evidence in favor of the fact of evolution.
If you knew anything at all about the genomes of organisms, which obviously you don’t, you’d know that genetics, along with every other line of evidence, show evolution to be an incontrovertible fact, like gravity and the earth going around the sun.
If however you truly believe that genetics somehow shows the fact of evolution not to be valid, by all means please trot out the reasons for your holding this delusion.
“The genetic code is unambiguous evidence in favor of the fact of evolution.”
Not to me, O believer in magical things . .
Michael.
Funny that you should mention Job, which includes so many of the prescientific concepts in the Bible which I cited, such as the immobility of the earth and the storehouses of precipitation, rather than the orbiting and earthquake-wracked earth and the hydrological cycle as understood by science:
Job 38 (New International Version):
1Then the Lord spoke to Job out of the storm. He said:
2“Who is this that obscures my plans
with words without knowledge?
3Brace yourself like a man;
I will question you,
and you shall answer me.
4“Where were you when I laid the earth’s foundation?
Tell me, if you understand.
5Who marked off its dimensions? Surely you know!
Who stretched a measuring line across it?
6On what were its footings set,
or who laid its cornerstone—
7while the morning stars sang together
and all the angelsa shouted for joy?
8“Who shut up the sea behind doors
when it burst forth from the womb,
9when I made the clouds its garment
and wrapped it in thick darkness,
10when I fixed limits for it
and set its doors and bars in place,
11when I said, ‘This far you may come and no farther;
here is where your proud waves halt’?
12“Have you ever given orders to the morning,
or shown the dawn its place,
13that it might take the earth by the edges
and shake the wicked out of it?
14The earth takes shape like clay under a seal;
its features stand out like those of a garment.
15The wicked are denied their light,
and their upraised arm is broken.
16“Have you journeyed to the springs of the sea
or walked in the recesses of the deep?
17Have the gates of death been shown to you?
Have you seen the gates of the deepest darkness?
18Have you comprehended the vast expanses of the earth?
Tell me, if you know all this.
19“What is the way to the abode of light?
And where does darkness reside?
20Can you take them to their places?
Do you know the paths to their dwellings?
21Surely you know, for you were already born!
You have lived so many years!
22“Have you entered the storehouses of the snow
or seen the storehouses of the hail,
23which I reserve for times of trouble,
for days of war and battle?
24What is the way to the place where the lightning is dispersed,
or the place where the east winds are scattered over the earth?
25Who cuts a channel for the torrents of rain,
and a path for the thunderstorm,
26to water a land where no one lives,
an uninhabited desert,
27to satisfy a desolate wasteland
and make it sprout with grass?
28Does the rain have a father?
Who fathers the drops of dew?
29From whose womb comes the ice?
Who gives birth to the frost from the heavens
30when the waters become hard as stone,
when the surface of the deep is frozen?
31“Can you bind the chainsb of the Pleiades?
Can you loosen Orion’s belt?
32Can you bring forth the constellations in their seasonsc
or lead out the Beard with its cubs?
33Do you know the laws of the heavens?
Can you set up God’se dominion over the earth?
34“Can you raise your voice to the clouds
and cover yourself with a flood of water?
35Do you send the lightning bolts on their way?
Do they report to you, ‘Here we are’?
36Who gives the ibis wisdomf
or gives the rooster understanding?g
37Who has the wisdom to count the clouds?
Who can tip over the water jars of the heavens
38when the dust becomes hard
and the clods of earth stick together?
39“Do you hunt the prey for the lioness
and satisfy the hunger of the lions
40when they crouch in their dens
or lie in wait in a thicket?
41Who provides food for the raven
when its young cry out to God
and wander about for lack of food?
JohnKnight
November 30, 2016 at 7:30 pm
That’s because you are totally, completely and utterly ignorant of the genetic code, Oh credulous believer in magical supernatural beings.
But, please, elucidate how you out of such ignorance, imagine that the genetic code shows the undeniable fact of evolution not to exist.
This should be highly amusing.
“That’s because you are totally, completely and utterly ignorant of the genetic code…”
Saw it in your imagination, so you know it’s a fact, eh, Evo justice warrior? ; )
John,
Not my imagination, but in the genetic codes of all the organisms whose genomes have been sequenced.
You asserted without any evidence whatsoever that the genetic code supports creationism. Kindly put up or shut up. Let’s see how you imagine that genetics supports creationism. The fact is that genomics not only supports the fact of evolution, but shows it plainly. Evolution can be observed in molecular detail thanks to genetics. The changes over time which have been inherited can be seen.
You’ve been shown many such observations here, but refuse to learn from them. Why do humans and other placental mammals still have (broken) genes to make yolk, for instance, when we don’t use yolk? The yolk sacs of our developing embryos don’t contain yolk. Since our embryos are nourished by their mothers, they don’t need yolk, so the genes for making it have degraded over time to such a degree that they’re no longer functional.
Why do tarsiers, Old World monkeys, New World monkeys and apes, including humans, have broken genes for making vitamin C, but not other primates, ie lorises and lemurs? Like most other animals, they can make their own vitamin C, but we members of the primate Suborder Haplorrhini all share the derived trait of being unable to produce this essential chemical. Clearly, the last common ancestor of the haplorrhini lost the ability to make vitamin C, but the last common ancestor of all primates still retained it. (Guinea pigs and the Indian fruit-eating bat are also incapable of making vitamin C, but their genes are broken in different places.)
Every year we find out more about genetics. Molecular clocks can now be fine tuned to the mutation rates in different lineages, providing ever more precise and accurate estimates of divergence times. Clocks can be checked against rocks, ie the fossil record.
This recent study found divergence dates of humans with our African ape kin farther back in time than some previous estimates. But the new dates comport with fossil evidence, which shows that humans and chimps diverged at least before seven million years ago and gorillas a minimum of ten million.
http://www.pnas.org/content/113/38/10607.full
“Abstract:
“Events in primate evolution are often dated by assuming a constant rate of substitution per unit time, but the validity of this assumption remains unclear. Among mammals, it is well known that there exists substantial variation in yearly substitution rates. Such variation is to be expected from differences in life history traits, suggesting it should also be found among primates. Motivated by these considerations, we analyze whole genomes from 10 primate species, including Old World Monkeys (OWMs), New World Monkeys (NWMs), and apes, focusing on putatively neutral autosomal sites and controlling for possible effects of biased gene conversion and methylation at CpG sites. We find that substitution rates are up to 64% higher in lineages leading from the hominoid–NWM ancestor to NWMs than to apes. Within apes, rates are ∼2% higher in chimpanzees and ∼7% higher in the gorilla than in humans. Substitution types subject to biased gene conversion show no more variation among species than those not subject to it. Not all mutation types behave similarly, however; in particular, transitions at CpG sites exhibit a more clocklike behavior than do other types, presumably because of their nonreplicative origin. Thus, not only the total rate, but also the mutational spectrum, varies among primates. This finding suggests that events in primate evolution are most reliably dated using CpG transitions. Taking this approach, we estimate the human and chimpanzee divergence time is 12.1 million years, and the human and gorilla divergence time is 15.1 million years.”
These are just some of the ways in which the genetic code shows the fact of evolution.
Put, please, by all means present the evidence from the genetic code which you suppose supports the lie of creationism. Thanks.
Phylogenetic tree for ten primates, from the article linked above:
http://www.pnas.org/content/113/38/10607/F1.expansion.html
http://www.pnas.org/content/113/38/10607/F1.medium.gif
Stevan Reddish
November 30, 2016 at 6:55 pm
I don’t argue for evolution. It’s a fact which requires no argument, ie an observation. I simply state some of the evidence for the inescapable conclusion that evolution has happened and is happening all the time.
CAGW by contrast is not an observation, ie a scientific fact, so the conjecture relies totally upon tendentious argument.
Please explain how you can possibly equate the incontrovertible fact of evolution with the politically motivated, repeatedly falsified hypothesis of catastrophic, man-made global warming.
All the evidence in the world shows evolution to be a fact. If you imagine you have evidence to the contrary, please present it. All the evidence in the world shows CAGW not to exist.
Stevan Reddish
November 30, 2016 at 8:03 pm
You have no points.
I’ve already dismissed the semantics that you imagine mean something, out of total ignorance.
“Similarities of form” aren’t the basis of evolutionary relationships, as you apparently believed out of total ignorance of biology. Why did you mention those supposed similarities in the first place, if you didn’t imagine that they meant something, which they don’t?
That reptilian scales have a dermal papilla shows the fact of descent with modification, which means that your inept attempt to show whatever creationist lies that you intended to show are false. Fish skin evolved into “amphibian” skin, which evolved into reptilian skin. Thanks for showing yet again the reality of evolution, for which there is all the evidence in the world and nothing against it.
You fail to understand the differences between the earliest “amphibians”, ie tetrapods, and subsequent, more derived amphibians. The earliest tetrapods didn’t live in the same environments as their “fish” ancestors. They moved onto the land.
Modern amphibians are highly derived tetrapods. They’ve lost a finger on their hands, ribs and a lot of other adaptations of their tetrapod ancestors.
Fish scales, again, are not the same as reptilian scales. Modern amphibians are highly derived from the last common ancestor of reptiles and modern amphibians. Carboniferous tetrapods were the ancestors of both modern amphibians and reptiles. They weren’t like modern amphibians in their skins and the other ways which you so ignorantly imagine.
You really need to study biology and paleontology. I can’t educate you completely in a blog comments section.
I realize now that when explaining the history of life on earth to people without any biological knowledge, I have first to define terms.
As with “scales”, I can now see that you also misunderstand “amphibian”. The first tetrapods were indeed “amphibians” in that they needed water in order to reproduce. But otherwise they were very different from modern amphibians, is lissamphibians, which are small and highly specialized. Being descended from large lobe-finned fish, the first tetrapods were big, but “amphibian” in the sense that they needed moisture in order to reproduce.
Modern amphibians, ie lissamphibians, are descended from the first tetrapods, as are reptiles (including birds) and mammals, but they’re highly evolved. They’re small, they breathe through their skin, they lack ribs and have only four fingers on their hands, but five on their feet.
In the Carboniferous Period, the tetrapod line leading to modern amphibians diverged from that leading to reptiles (and birds) and mammals, ie the amniotes, vertebrates which lay eggs in dry environments. The mammal (synapsid) line soon diverged from the reptile (diapsid) line.
I hope this helps clear up your misunderstandings. Please study biology before presuming to comment upon it, as I don’t comment on aerospace engineering. Thanks.
Chimp November 30, 2016 at 6:51 pm
I am indeed aware that my hypothetical marine mammal sequence of evolution fails upon examination of the details. I was pointing out that similarities of form do not confirm evolution.
I am also aware of the differences between reptilian scales and fish scales, though the differences are not as great as you state. From the same source: “All reptilian scales have a dermal papilla underlying the epidermal part.”
Did you overlook the part where I stated a possible scenario: “Amphibians lost their scales, then early reptiles re-evolved scales.” I believe this is the scenario you support.
Evolutionary theory states that morphologies that are beneficial are retained. I asked the question: why did those amphibians living in the same environments as fish not retain the scales they inherited from fish?
I also implied : If scales were beneficial for reptiles, why didn’t amphibians living in the same environment retain their scales?
As for your explanation of why reptiles needed scales (arid environment), if reptiles evolved from amphibians, wouldn’t they have been in the same environment? Is a crocodiles environment different from that of supposed early amphibians? Or of “later” frogs and toads? Though dinosaur bones are found in areas that are desert today, they were not deserts when the dinos were alive.
Are you going to address my points or point out a dino that lived in a desert?
SR
Nature does not support the scenario which you assert falsely I support.
I answered your questions but my reply has disappeared. So here goes again.
You confuse modern amphibians with their tetrapod ancestors (“amphibian” in that some still lived in water and that they all needed water to reproduce) and imagine that reptiles evolved from creatures like modern amphibians. They didn’t.
Modern amphibians and reptiles evolved from common ancestors, but went their separate ways. The earliest tetrapods were large and robust, as indeed were their lobe-finned fish ancestors. They had ribs, unlike small, modern amphibians. The first amniotes were also small, but they adapted to the increasingly drier environment by developing shelled eggs and thicker skin. Meanwhile in the modern, lissamphibian line, skin was getting thinner so that adults could respire through it in their moist environments.
The Carboniferous suffered an ice age, which caused the previous coal swamps to dry out. Amniote (reptile and mammal ancestors) evolution responded to environmental changes in their Euramerican habitat. Ancestral lissamphibians stayed in moister conditions.
Lots of dinos lived in deserts, but of course the dinos came along a long time after their first amniote ancestors.
Chimp December 1, 2016 at 9:51 am
“You confuse modern amphibians with their tetrapod ancestors (“amphibian” in that some still lived in water and that they all needed water to reproduce) and imagine that reptiles evolved from creatures like modern amphibians. They didn’t.
Modern amphibians and reptiles evolved from common ancestors, but went their separate ways. The earliest tetrapods were large and robust, as indeed were their lobe-finned fish ancestors. They had ribs, unlike small, modern amphibians. The first amniotes were also small, but they adapted to the increasingly drier environment by developing shelled eggs and thicker skin. Meanwhile in the modern, lissamphibian line, skin was getting thinner so that adults could respire through it in their moist environments.”
Chimp, you seem to be repeating what you were taught, without a thought to how or whether it applies to the subject at hand.
You tell me not to assume that reptiles evolved from modern amphibians (not that I said they did), because the early amphibians from which amniotes evolved were “large and robust”. Then you say those first amniotes were also small like modern amphibians.
You are not responding to what I say, but merely regurgitating dogma. This is one reason why I said earlier that you argue using the same methods as warmists. I don’t see any point to further discussion.
SR
Stevan Reddish
December 4, 2016 at 11:31 pm
I’m not regurgitating dogma but reporting on what has been observed, by myself included, and try to explain it to you, while disabusing you of your misconceptions.
I’ll try again. You are confused in imagining that the ancestral “amphibians” had skin like modern amphibians. They didn’t. Here is what happened.
The first tetrapods were “amphibians” in that some lived in water and all required moist conditions in which to reproduce. But unlike modern lissamphibians, they were large, with full ribs, unlike today’s small amphibians.
These tetrapods were the ancestors of both amniotes (mammals and reptiles, including birds) on the one hand and lissamphibians on the other. While some tetrapod lineages remained large and robust, others adapted to changing and new environments by getting smaller.
One line of the smaller tetrapods evolved increasingly “reptilian” features, leading eventually to amniotes. Their skin became thick and scaly, the better to live in dry habitats. Another line of smaller tetrapods developed lissamphibian features. Their skin became smooth, the better to respire in wet environments.
You seem to imagine that ancestral tetrapods had skin like modern amphibians, which they didn’t. It was more like the skin of the fish from which they evolved. So one line of their smaller descendants evolved thicker, scaly (in the reptilian way) skin, while another evolved thinner skin.
Hence, the problem which you imagined based upon “scales” doesn’t exist.
This isn’t dogma, it’s reality, as observed in the fossil record, in embryology, biogeography, biochemistry, the genomes of animals living today and every other line of evidence. It’s scientific fact.
The transition to amniotes from tetrapods is well recorded. We know when and where (Euramerica) it happened. The transition from tetrapods to lissamphibians is less well recorded, since the earliest amphibians were small and lived in environments not conducive to preservation. There are few fossils of them from the Late Carboniferous and Permian Periods, but they’re more plentiful in Triassic rocks. Molecular clocks however show that they must have evolved at about the same time as their amniote kin, ie in the Carboniferous.
Misleading. Sulphur eating bacteria exist abundantly everywhere, not just in deep oceans. They are even used in hydrometallurgical treatment of sulphide ores. They were discovered in the 1950s at Kennecott eating up the copper sulphide in the tailings and releasing soluble copper sulphate which turns run-off water bright blue.
Cleverly, they began collectiing the garbage in Salt Lake City, incinerating it down to tin cans and scrap iron which they dumped into the blue effluent and which instantly turned the iron into copper metal. Tin cans used to be “tinned’ so they also recovered the tin. I visited Bingham Canyon and copper deposits in Sw USA in early 70s. You could put your geological hammer in blue puddles on the open pit floors and coat them with gleaming copper.
Making these ubiquitous bugs rare and restricted to deep oceans and ancient times is the kind of thing these folks do to make themselves more clever. Moreover they don’t want to queer up their weak thesis on the reason for the big oxygenation of earth by having these sulphuric acid making bug s so commonplace.
Quite so. The first oxygenation event (iron ore forming, the great rusting) followed the evolution of shallow water photosynthesizing cyanobacteria. The fossilized mats of these colonies are called stromatolites and can be found in Australia. Phytoplankton are thought to have evolved later, and played the major roll in the Cambrian oxygenation event ~500 mya.
Australian stromatolite fossils date from 3.4 billion years ago. This year, similar fossil bacterial slime mats were found in Greenland, from 3.7 Ga.
http://www.sciencemag.org/news/2016/08/hints-oldest-fossil-life-found-greenland-rocks
Indeed. I once had a couple of very pretty fossils of Devonian cephalopods preserved as Iron Pyrite (Fe2S-“Fools Gold”) reduced to white powder by thiobacteria that apparently traveled by air from who-knows-where to the boxes where the specimens were stored.
Pity!
I subscribe to the proposition that knowledge is inversely proportional to the number of questions we have no answers for. When reading any scientific article I convert words like assume and theorize to guess. Often my Thesaurus and Dictionary get quite a work out. The title of the article is bogus. There are far too many guesses and qualifications. Also, these examples are found in only two locations. Their rarity makes them suspect. Looking the same does not make them the same.
Reminds me of the mineral deposits in the “Mars Rock” that some folks at NASA GSFC were calling biological and Bill Clinton went on TV to explain to the World his new findings, instead of explaining his “rendezvous” with a White House Intern and a cigar.
Those are tiny nanobes, if fossils of organisms. The South African fossils are of enormous bacteria.
These are maybe what we should be looking for on Mars.
I thought it was an aerial view of Burning Man.
“Life before oxygen”?
What types of nuclear reactions then happened to break larger atoms down to the size of oxygen?
Big Bang?
Was there “life” before it?
Abiogenesis after it?
Lots and lots of questions. Lots and lots of theories supporting each other to fit observations into the desired answers.
A pitfall of science. I admire men and women who remain honest in the field.
(Money, politics, ideology have not made it easy.)
Oxygen is made in stars. It’s the third most common elements in the universe, after hydrogen, helium. It’s not made by breaking down larger atoms but by nucleosynthesis in main sequence stars.
You seem confused about chemistry. The article refers to the time before there was plentiful free molecular oxygen, the gas O2, in the air and oceans of earth. For the first two billion years of earth history (and more), almost all oxygen here was locked up in compounds like water and carbon dioxide.
Life as we know it needs oxygen, but happily, as noted, it is abundant in the universe. At the time of the formation of our solar system, stars had been making oxygen for billions of years.
Hope that answers some of your questions. Nucleosynthesis is not a theory. It’s a fact. This stuff isn’t made up to get the desired answers. Physics, chemistry and biology aren’t like bogus “climate science”.
So it’s fusion and not fission? Oxygen is made in stars? I’ve heard that theory. You say it’s a fact. Who observed it? Who took the measurements? How did it get from a star to a planet?
We have no past observations. We have current observations.
I’ll repeat my comment with edits.
(In Ben Stein’s Expelled a famous atheist said that he thinks aliens brought “life” to Earth. Maybe they brought Oxygen too?)
@Chimp
November 30, 2016 at 4:14 pm: Good exposition, Chimp. Life needs energy, electrons supply it down a ‘gradient’. Oxidants are ‘electron carriers’, able to supply them for that process. Oxidised hydrogen can be H2O or H2S for instance, because Sulphur does the same job in the relative unavailability of oxygen. Photosynthesis via the levers of enzyme catalysts and the power of light, gets the electrons into Adenosine diphosphate-triphosphate ATP where it can form sugars from CH2O, the fuel of life.
We could expect, as inferred, that energetics would favour the ‘aerobic’ system when it evolved. But ‘Anaerobia’ is still there, in the game.
Brett,
Yup. From early chemosynthetic organisms to photosynthetic bacteria isn’t a huge leap.
A mentor named John Ellistion has a new text in publication, decades of research into the part played by colloidal processes in rock and ore formation. It is likely to be a paradigm changer.
One observation is that some colloidal textures now seen in rock can be spherical, with interior features of similarity to others nearby. Caution is needed when deciding if a texture is colloidal or replacement/biological.
Not saying it applies to this paper, just injecting caution.
Geoff.
Darn, that is John Elliston. The i was an auto insert nuisance.
Geoff.
Michael J Dunn said,..
“Oh, bosh. If there were no oxygen in the atmosphere, there would be nothing to prevent UV from shining directly on water and generating oxygen from the splitting of the water molecules”.
It didn’t happen though.
The oldest oxygen producers were probably stromatolites [cyanobacterial sheets] and were possibly around 3.7 billion years ago. It wasn’t until about 2.45 billion years ago that oxygen reached “significant ” levels in the atmosphere
But it should have happened, because nitrogen is not a significant absorber of UV. And I don’t expect that the solar spectrum was deficient in UV at that time. “It didn’t happen though.” You were there to see it not happen? It is just interesting to me that if a scientific fact or implication does not fit into a “consensus” narrative, it is regarded as nonexistent.
The implication is that such a mechanism may have “speeded-up” the accumulation of oxygen in the atmosphere, in addition to or prior to any organic contributions. As far as I am concerned, it may still be ongoing.
Oxygen produced by whatever chemical, physical or biological process prior to the banded iron formations would have been in small enough quantities from the environment to absorb it into compounds. Only after the iron rusted did the oxygen bubbling from all those photosynthetic organisms get released into the water and thence the air.
Should and did are different
UV may have produced oxygen but there is not much evidence of oxygen in the atmosphere until around 2.5 billion years ago, and even then not a lot. What oxygen that was produced seems to have been soaked up by marine carbonate sediments and banded iron formations
https://en.wikipedia.org/wiki/Banded_iron_formation
http://www.hou.usra.edu/meetings/abscicon2015/pdf/7335.pdf
Atmospheric O2 didn’t reach approximately contemporary levels until around 500 million years ago
UV may still be producing O2 from water but at such insignificant levels it is totally masked by biological production.
Since the Cambrian Period, oxygen concentrations have fluctuated between 15% and 35% of atmospheric volume. It was low enough in the Cambrian and Ordovician that human visitors to those periods would need oxygen tanks. But it spiked dangerously high during the Carboniferous Period, when wild fires could rage across whole continents and giant predatory dragonflies patrolled the coal swamps.
But even in the Cambrian, O2 was greatly elevated over the vast majority of geologic time:
https://en.wikipedia.org/wiki/File:Oxygenation-atm-2.svg
A cartoon of mine seems apropos here …
http://www.maxphoton.com/before-nuts/
Love it.
Although some prokaryotes benefited from more oxygen, along with their eukaryotic younger but bigger kin.