What delayed Earth's oxygenation?

What delayed Earth's oxygenation?

Powering a massive biosphere on Earth, photosynthesis is the light-mediated reaction that converts carbon dioxide and water to carbohydrates and oxygen. About 2.3 billion years ago, this reaction led to a dramatic oxygenation of Earth's atmosphere.

Evidence exists for oxygen-releasing photosynthesis evolving much earlier—perhaps as early as 3 billion years ago. However, the we take for granted today has existed for only about 10 percent of Earth's 4.5-billion-year history. Why did oxygenation of the occur so much later than the evolution of oxygen-releasing photosynthesis?

"The striking lag has remained an enduring puzzle in the fields of Earth history and ," says Christopher Reinhard, an assistant professor in the School of Earth and Atmospheric Sciences (EAS).

Reinhard, former EAS postdoctoral researcher Kazumi Ozaki, and collaborators have proposed a solution to the puzzle. Their findings, published in Nature Communications, suggest that in the oceans of early Earth, oxygen-releasing photosynthesizers could not compete effectively with their primitive counterparts.

Modern photosynthesizers consume water and release oxygen. Primitive ones instead consume dissolved iron ions—which would have been abundant in the oceans of early Earth. They produce rust as a byproduct instead of oxygen.

Using experimental microbiology, genomics, and large-scale biogeochemical modeling, "we found that that use iron instead of water are fierce competitors for light and nutrients," says Ozaki, the paper's first author and now an assistant professor in the Department of Environmental Science at Toho University, in Japan. "We propose that their ability to outcompete oxygen-producing photosynthesizers is an important component of Earth's global oxygen cycle."

The study is part of Reinhard's research goal to understand how the evolution of the photosynthetic biosphere controlled the composition of Earth's atmosphere. "We want to understand the timing of major biological innovations and their impact on the chemistry of Earth's oceans and atmosphere. We consider these principles to be central in understanding our own evolutionary origins and the search for life beyond our solar system."

"Our results contribute to a deeper knowledge of the biological factors controlling the long-term evolution of Earth's atmosphere," Ozaki says. "They offer a better mechanistic understanding of the factors that promote oxygenation of the atmospheres of Earth-like planets beyond our solar system." The results "yield an entirely new vantage from which to build theoretical models of Earth's biogeochemical oxygen cycle," Reinhard adds.


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Ammonium fertilized early life on Earth: study

More information: Kazumi Ozaki et al. Anoxygenic photosynthesis and the delayed oxygenation of Earth's atmosphere, Nature Communications (2019). DOI: 10.1038/s41467-019-10872-z
Journal information: Nature Communications

Citation: What delayed Earth's oxygenation? (2019, July 12) retrieved 22 July 2019 from https://phys.org/news/2019-07-earth-oxygenation.html
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Jul 12, 2019
This sounds like the banded iron layers are clearly caused by iron fixing life.

Jul 12, 2019
well, one more reason for the lack of SF fantasy worlds
if this Earth, in the best possible of stable Stellar environments
spent 90% of it's existence dominated by Anoxygenic photosynthesis?

per the research behind this article, Earth's biome was dominated by iron consuming Anoxygenic bacteria using photosynthesis
that resulted in rust
which trapped the oxygen they produced

what are the odds for any other similar pairings to Sol-Earth achieving the cycle of CO2/Water/Oxygen photosynthesis biosphere?

if it ain't broke? why change it?
no need for evolution for the microbugs, grown fat & sassy chewing iron & pooping rust!

with the addition of billions of years of bombardments by space junk
endlessly resupplying the Earths crust with iron & phosphates

this article is doleful news for anyone waiting for aliens bearing us the Wisdom of the Ancients
keep in mind... the far-ranging aliens are going to be pissed if we do not leave them any monkeys to fuck!

Jul 12, 2019
Using H2O and CO2 to make hydrocarbons is pretty straightforward, break off the hydrogen and carbon and connect them, releasing the oxygen.
How the hydrocarbons are made out of iron is puzzling to say the least.
And the article was absolutely silent on that particular of the discovery.

As for the banded iron deposits, iron dissolves in water without oxygen, add oxygen and it precipitates into the rust deposits known as banded iron layers. The iron is not used, it is just there and absorbs the oxygen, which definitely is the result of photosynthesis.

Either the major portion of this research was just skipped entirely or there is less to the story.

Jul 12, 2019
From the abstract

...competition for light and nutrients in the surface ocean between oxygenic phototrophs and Fe(II)-oxidizing, anoxygenic photosynthesizers (photoferrotrophs) translates into diminished global photosynthetic O2 release when the ocean interior is Fe(II)-rich. These results provide a simple ecophysiological mechanism for inhibiting atmospheric oxygenation during Earth's early history. We also find a novel positive feedback within the coupled C-P-O-Fe cycles that can lead to runaway planetary oxygenation as rising atmospheric pO2 sweeps the deep ocean of the ferrous iron substrate for photoferrotrophy.

It sounds like the photoferrotrophs with their primitive feeding habits literally ate themselves out of house and home. The surface sunlight zone, or Epipelagic Zone, only supported the critters for a limited time and it's possible some of the organisms may have evolved to become regular phototrophs themselves, I wager.

Jul 12, 2019
The rhetorical question in the title assumes that scientists know well how things were billions of years ago. Nothing could be further from the truth. It is 99.99% a fantasy. All built upon the crumbling foundation of the evolution lie. Please move on to more serious topics.

Jul 12, 2019
lol .. u so smart !! ..lol

Jul 12, 2019
The rhetorical question in the title assumes that scientists know well how things were billions of years ago. Nothing could be further from the truth. It is 99.99% a fantasy. All built upon the crumbling foundation of the evolution lie. Please move on to more serious topics.


What has radiometric dating got to do with evolution, you superstitious, uneducated clown?

Jul 12, 2019
Theorizing how the Earth formed into its current state is serious Bart. It helps connect the dots in understanding biogeochemical processes that may also be happening on other worlds. When the next generation of space telescopes set their sights on planets in other star systems, we'll have a lot more observable celestial bodies in which to consolidate our speculative theories on planet formations and life in general.

Jul 12, 2019
etherair, i think i understand the points you are making in your comments
i suspect we are looking at different sets of evidence
much of it based on conjecture

it is possible that there have been a lot more overlap of evolutionary processes than nice, neat OCD0apprived categories would suggest.

example, if today, a major Global catastrophe should shatter the present Earth's crust?
& far into the future curious sophonts evolve to reinvent the Scientific Method & begin exploring the history of their Earth?
before their futurist biosphere developed?

only to discover from our time period, the remains of ocean bottom smokers & shoreline
stromatolites from various ages?

how much accurate understanding of our geologic period would you expect of those future researchers?

my understanding of the Oxygenation "The Great Murder"
occurred an estimated two billion years ago +/- take a guess

- cont'd -

Jul 12, 2019
- cont'd -

which contradicts the conclusion of this article that it occurred approx 400 million years ago

so there is a lot of room to debate this subject
until conclusive proof can be tech verified, confirmed from ,multiple sources & peer-reviewed

etherair, i do have to disagree about your conclusion that this article failed for not explaining the historical deposits of coal & petrochemicals

per this article, the researchers claim that the epoch of global domination by iron-to-rust photosynthesizing bacteria ended about 400 million _+/-years ago

the Carboniferous Era ran into the Permian Age est 300 to 200 mill years ago
so it occurred well within the Free Oxygen Age
& after the time period specified by this research

Jul 12, 2019
Google states:

By volume, dry air contains 78.09% nitrogen, 20.95% oxygen, 0.93% argon, 0.04% carbon dioxide, and small amounts of other gases.

I think what the article is implying is that it took from 4.5 billion years ago to 450 million years ago to attain the above stated volume of atmospheric oxygen. And that oxygen producing oceanic organisms evolved 3 billion years ago, but for around 700 million years after their appearance they were outcompeted for nutrients by the rust producing oceanic organisms.

At the 2.3 billion year mark, there just wasn't enough iron in the ocean to sustain the rust producing organisms reproduction cycle and oxygen producing organisms began to claim the oceans.

Jul 13, 2019
I am not necessarily being a crank just for fun.
The finding seem based on models that do not reflect known facts of the past composition of the oceans.
Continuing to force facts to fit theories after it is obvious they do not is bad science. Nothing wrong with new ways to look at things, but having them match reality is a real plus.
Iron consuming lifeforms are in existence. hemoglobin is just chlorophyll with an iron atom replacing the magnesium at the center, the only difference between the two. But the iron allows transport of oxygen while magnesium transports hydrogen.
But saying iron based life dominated early oceans is a stretch not accounted for with current known facts.

Interesting for sure, but serious?

Jul 13, 2019
I am not necessarily being a crank just for fun.
The finding seem based on models that do not reflect known facts of the past composition of the oceans.

What part of the models do you disagree with? That anoxygenic photosynthesis existed at the time in question is known and discussed in the paper. The paper also makes the case that the Chlorobium phaeoferrooxidans used in the study would have a similar counterpart in the primitive oceans, so their hypothesis would seem to at least be possible. This isn't my field, though, so I may be missing something. What part of the paper are you disagreeing with?

Jul 13, 2019
Seems like a credible model.

Using H2O and CO2 to make hydrocarbons is pretty straightforward, break off the hydrogen and carbon and connect them, releasing the oxygen.
How the hydrocarbons are made out of iron is puzzling to say the least.
And the article was absolutely silent on that particular of the discovery.


That is not part of the discovery; you must understand the context of the science as well (using, say, helpful ELINTs or reviews). Metabolism converts energy (which is what the paper deals with) and nutrients (which is known metabolism, most commonly glycogenesis and the Calvin cycle https://en.wikipe...n_cycle; the Chlorobi they studied use the RTCA cycle however: "These autotrophs fix carbon dioxide using the reverse tricarboxylic acid (RTCA) cycle" https://en.wikipe...bacteria ).

- tbctd -

Jul 13, 2019
- ctd -

The finding seem based on models that do not reflect known facts of the past composition of the oceans.


A claim notably without evidence, or even sense: why would they do that and why would the peer reviewers let them? The abstract mentions "... we combine experimental microbiology, genomic analyses, and Earth system modeling ..." and they explain a well known observation: "The striking lag has remained an enduring puzzle in the fields of Earth history and planetary science". The BIFs you mention attest to the amount of iron that early oceans contained.

You seem more of a troll that want to spit on the carpet and yell in our ears than a crank that want to crank out an 'idea'.

Jul 13, 2019
what are the odds for any other similar pairings to Sol-Earth achieving the cycle of CO2/Water/Oxygen photosynthesis biosphere?
@rrwillsj We do not and cannot know the odds because we currently have a sample of "1". The odds of microbial life in the universe resulting in photosynthesis might range from 1 (i.e. just Earth) to thousands, millions, billions or even trillions. We simply have no idea.

We also have no idea if photosynthesis and oxygen are even required for life to evolve to a somewhat advanced stage (e.g. multicellular life but not necessarily intelligent). Anaerobic bacteria do not require oxygen, even today, and they do just fine. Aerobic organisms are more flexible and efficient but we have only Earth's anaerobic microbes to compare them against.

What about RNA, DNA, necessity of water as a solvent and carbon as the basis of life? We have no idea if any of these are or need to be essential elements of life beyond Earth.

Jul 14, 2019
Multiverses are peer reviewed, so is string theory, as was slavery.
The lag is real, but attributing it to what appears to be a very minor anomalous cell line is a stretch. The delay is explained both easily and better with current theories and statistically prevalent lifeforms.
Very rarely are entire lines of research overturned, much more common is refinement.
Did iron eating organisms have an influence on early life? Odds are good.
Was an iron consuming organism the prime mover of early life and creator of the very composition of the Earth? Odds are much poorer.

The idea of spitting on carpets did not occur to me. Am I just not paranoid enough about the motives of others? I keep assuming sincerity, misguided at times but not deliberately deceptive.
Science and religion, really, there is a difference. Religion is personal and science just is.
Folks getting personal about science sometimes confuses me.

Jul 14, 2019
torbjorn
i do not agree with your description of etherair as a troll
i do not agree with etherair's description of himself as a cran
to me, based on these few comments of his?
i am of the opinion that he has a limited, narrow view of this subject

so not a troll not even a crank
as he is honestly admitting he doesn't understand the conjectures of this article
or how that correlates with the knowledge base he does have

torbjorn, the cranks & trolls you usually deal with do not ask honest questions nor accept correction oferror

now i am being a cranky troll
because i consider the conclusion's to this research to be bad news for the different versions of the panspermia mythology
also i corrected etheraair's misinterpretation of why the article writer's did not mention the Carboniferous Age

to paraphrase my comments
"we are all blindmen trying to describe an elephant by feeling different parts of it's body"

then each of us insisting that the part we felt describes the entire animal...

Jul 14, 2019
Sahstar
i appeove that you were willing to admit that there are many potential parts to this puzzle that are still missing
that there we have not yet found evidence for life anywhere but here on Earth

then you blow it all up making fabulist claims for "what must be!"
why?
why? must life be spread across the Universe?
much less this small corner of our galaxy?

why do you insist that reality must agree with your wishes?

just wanting it doesn't make it true
those gifts under the yuletide tree were not actually delivered by a corpulent elf.

you were intellectual explaining how much data we are still missing.

you were emotional when you insist that your speculations have to come true because it is what you want to have fulfilled

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