Great Oxygenation Event: MIT Scientists’ New Hypothesis

[Genady]

Quote

A new hypothesis, proposed by MIT scientists, suggests that oxygen finally started accumulating in the atmosphere thanks to interactions between certain marine microbes and minerals in ocean sediments. These interactions helped prevent oxygen from being consumed, setting off a self-amplifying process where more and more oxygen was made available to accumulate in the atmosphere.

The scientists have laid out their hypothesis using mathematical and evolutionary analyses, showing that there were indeed microbes that existed before the GOE and evolved the ability to interact with sediment in the way that the researchers have proposed.

Great Oxygenation Event: MIT Scientists’ New Hypothesis for One of the Grand Mysteries of Science (scitechdaily.com)

[exchemist]

7 hours ago, Genady said:

Great Oxygenation Event: MIT Scientists’ New Hypothesis for One of the Grand Mysteries of Science (scitechdaily.com)

 I had to go to the paper itself to find out what these POOM species are: https://doi.org/10.1038/s41467-022-28996-0

Seems, as I suspected, they are organic compounds with hydroxyl and carboxylic acid groups on them. These will be polar and presumably able to bond to silicates by H-bonding. The interesting thing is that the paper associates the oxygenation event* with evolution of the enzymes that catalyse such partial oxidation, suggesting it was this evolutionary step that led to it.

*I'm pleased the article called it the Great Oxygenation Event rather than the alternative Great Oxidation Event. I always find the latter misleading, as it was really, from the planet's point of view, a reduction event, leading as it did to free oxygen everywhere! 

 

[studiot]

11 minutes ago, exchemist said:

 I had to go to the paper itself to find out what these POOM species are: https://doi.org/10.1038/s41467-022-28996-0

Seems, as I suspected, they are organic compounds with hydroxyl and carboxylic acid groups on them. These will be polar and presumably able to bond to silicates by H-bonding. The interesting thing is that the paper associates the oxygenation event* with evolution of the enzymes that catalyse such partial oxidation, suggesting it was this evolutionary step that led to it.

*I'm pleased the article called it the Great Oxygenation Event rather than the alternative Great Oxidation Event. I always find the latter misleading, as it was really, from the planet's point of view, a reduction event, leading as it did to free oxygen everywhere! 

 

Good points. +1

Especially as the original posted source website is one that shows dangerous, possibly illegal, crap like this on the same page.

[exchemist]

12 minutes ago, studiot said:

Good points. +1

Especially as the original posted source website is one that shows dangerous, possibly illegal, crap like this on the same page.

Well this is off-topic of course, but I do know "Voltex" is a well-worn scam, exploiting ignorance about power factors and wattless current. I suspect "Voltax" is the same schtick. Websites seem to have little control over whose ads pop up. I complained about Voltex ads on another science forum and the admin told me they had no way to stop them. So I wouldn't blame the website, except insofar as it accepts ads in the first place.

Edited March 15, 2022 by exchemist

[Genady]

1 hour ago, exchemist said:

 I had to go to the paper itself to find out what these POOM species are: https://doi.org/10.1038/s41467-022-28996-0

Seems, as I suspected, they are organic compounds with hydroxyl and carboxylic acid groups on them. These will be polar and presumably able to bond to silicates by H-bonding. The interesting thing is that the paper associates the oxygenation event* with evolution of the enzymes that catalyse such partial oxidation, suggesting it was this evolutionary step that led to it.

*I'm pleased the article called it the Great Oxygenation Event rather than the alternative Great Oxidation Event. I always find the latter misleading, as it was really, from the planet's point of view, a reduction event, leading as it did to free oxygen everywhere! 

 

This hypothesis is more subtle than the one of direct pumping oxygen into atmosphere by cyanobacteria. I was surprised to learn that the latter is not as settled as I thought.

[exchemist]

6 minutes ago, Genady said:

This hypothesis is more subtle than the one of direct pumping oxygen into atmosphere by cyanobacteria. I was surprised to learn that the latter is not as settled as I thought.

Indeed. What always impresses me about these things is how one sets about getting any sort of handle on events that long ago, that involve life. 

[studiot]

16 minutes ago, exchemist said:

Indeed. What always impresses me about these things is how one sets about getting any sort of handle on events that long ago, that involve life. 

Our knowledge of oxygen processes in the atmousphere, land and oceans is, not surprisingly, far greater for the past half a billion years than for the previous nearly 4 billion years.
We know today that there have been non organic processes associated for instance with the sulphur cycle in that most recent period.
One fact has been determined is that the enzyme Rubisco, originally from the cyanobacteria nearly 3 billion years ago, is still used by plants today.

 

https://en.wikipedia.org/wiki/RuBisCO

Edited March 15, 2022 by studiot

[joigus]

1 hour ago, studiot said:

Our knowledge of oxygen processes in the atmousphere, land and oceans is, not surprisingly, far greater for the past half a billion years than for the previous nearly 4 billion years.
We know today that there have been non organic processes associated for instance with the sulphur cycle in that most recent period.
One fact has been determined is that the enzyme Rubisco, originally from the cyanobacteria nearly 3 billion years ago, is still used by plants today.

 

https://en.wikipedia.org/wiki/RuBisCO

Very interesting thread and comments...

RuBisco is the single most abundant protein on the biosphere. I would be surprised that it didn't have to do with major oxygenation events in the past. But the origins of this oxygenation event may be buried in complexity.

[CharonY]

2 hours ago, joigus said:

RuBisco is the single most abundant protein on the biosphere. I would be surprised that it didn't have to do with major oxygenation events in the past. But the origins of this oxygenation event may be buried in complexity.

Not sure I follow. RuBisco is sensitive to oxygen (or rather, oxygen and CO2 both compete for the binding site) and increasing oxygen levels lower the effectiveness of carbon fixation. Or do you mean their abundance increased in response to oxygenation...?

[exchemist]

2 hours ago, joigus said:

Very interesting thread and comments...

RuBisco is the single most abundant protein on the biosphere. I would be surprised that it didn't have to do with major oxygenation events in the past. But the origins of this oxygenation event may be buried in complexity.

As I read it, this paper does not challenge the primacy of photosynthesis in generating free oxygen. What it suggests is that the suddenness of the 2 oxygenation events can perhaps be explained by a positive feedback effect by which, once partial oxidation enzymes evolved, binding to marine sediments of partially oxidised metabolic byproducts would accelerate the rate of burial of organic matter. This would reduce the competition among the various oxygen-consuming processes, encouraging more free oxygen. And the more of that there was, the more organic matter would be partially oxidised and so the more efficient that burial process would be, and so on. Until there was so much partially oxidised material (i.e. so much chemical detritus from life processes) that, even though a lot of it was bound to minerals it nevertheless could take up enough oxygen for a balance to be reached, but at a far higher free O2 level than before.    

Or something like that - I have only skimmed it.

(By the way, Rubisco always makes me think of Shredded Wheat................😁)

[joigus]

6 hours ago, CharonY said:

Not sure I follow. RuBisco is sensitive to oxygen (or rather, oxygen and CO2 both compete for the binding site) and increasing oxygen levels lower the effectiveness of carbon fixation. Or do you mean their abundance increased in response to oxygenation...?

No, I'm sure I made a mistake there. RuBisco is about Calvin-Benson cycle, right? Producing sugars. 😅 Thanks for catching me.

 

6 hours ago, exchemist said:

As I read it, this paper does not challenge the primacy of photosynthesis in generating free oxygen. What it suggests is that the suddenness of the 2 oxygenation events can perhaps be explained by a positive feedback effect by which, once partial oxidation enzymes evolved, binding to marine sediments of partially oxidised metabolic byproducts would accelerate the rate of burial of organic matter. This would reduce the competition among the various oxygen-consuming processes, encouraging more free oxygen. And the more of that there was, the more organic matter would be partially oxidised and so the more efficient that burial process would be, and so on. Until there was so much partially oxidised material (i.e. so much chemical detritus from life processes) that, even though a lot of it was bound to minerals it nevertheless could take up enough oxygen for a balance to be reached, but at a far higher free O2 level than before.    

 

OK. Thank you. I'm dabbling on chemistry/biochemistry, so some of the details went over my head, but I think I got the gist of it.

Were those oxygenation events really that sudden? The banded iron formation suggests some kind of periodicity in that massive oxidation of the oceanic iron. Could a picture that you just sketched be compatible with some kind of periodicity?

The closest I know from my past study of differential equations is the periodicity in populations that appears in models of competing species, like the Volterra model, which is about a predator-prey dynamics. Does a pattern like that make any sense at all in biochemistry of the oceans? I address this mainly to @CharonY and @exchemist, but feel free to answer other members, of course.

6 hours ago, exchemist said:

(By the way, Rubisco always makes me think of Shredded Wheat................😁)

Calvin-Benson always reminds me of underwear 😆

[studiot]

In fact this work seems to be a development of the work of Berner (reference 45 in the paper) and Canfield (reference 1 and the paper)