Fossil evidence of photosynthesis gets a billion years older | Hacker News Reader

Fossil evidence of photosynthesis gets a billion years older

arstechnica.com

54 pointsBrajeshwar49 comments

I think TFA's title is wrong; it doesn't (seem to) dispute the age of the first photosynthesizing cyanobacteria. Apparently they have pushed back the age of the earliest "thylakoid membranes", which (on my reading - I didn't find it clear) are required for a cell to incorporate a cyanobacterium.

So perhaps (if I read it correctly) the title should be "Fossil evidence of photosynthetic cells gets a billion years older". But even that is a stronger claim than TFA makes; the presence of thylakoid membranes doesn't mean that the cyanobateria manifesting them were incorporated in photosynthetic cells.

The author seems to make the false assumption that the real "hard" evidence for photosynthesis is fossil-based. And so that this is now the best proof that exists. I'm guessing the article is confused because he's not an expert in the field and probably hasn't looked into it deeply. That's frankly the problem with most pop-science reporting. Even if they wanted to, nobody who writes for a living has the time to actually become an expert in so many different fields. So they write about things they don't understand.

The cyanobacterium itself is a photosynthetic cell. Bacteria are cells. The thylakoid membrane is a structure inside those cells.

You seem to be confusing this with the origin of eukaryotic, chloroplast-based photosynthesis, which is indeed a different question.

You're right: I probably confounded "cells" with eucaryotic cells. My understanding (from school biology half a century ago) is that a strong candidate for the origin of chloroplasts is cyanobacteria, incorporated as guests.

I'm not sure that eucaryotic cells are the only kind of "big" cells that could adopt cyanobcteria as organelles.

Anyway, I wasn't considering bacteria as "cells".

Yeah, the chloroplasts=cyanobacteria thing is pretty near settled these days. :)

NB it's just (one method of) actual evidence that got pushed back, not the hypothesised origin of photosynthesis.

For a very long time it has been pretty certain that oxygenic photosynthesis must be much older than these new fossils, perhaps even one billion years older.

However the evidence has been indirect, due to the increase in abundance of certain oxidized minerals in the more recent rocks.

This new research has shown direct evidence, i.e. fossils that appear to be Cyanobacteria of a kind known to be able of performing oxygenic photosynthesis.

This sounds like the Great Filter is getting pushed further back, making human level cognition elsewhere in the universe potentially even more rare.

What makes human cognition so important? Because you have it?

You are no more special than a mosquito.

Oh come on, a mosquito and an entity capable of imagining and predicting a Higgs boson are equivalent?

Most humans I encounter* are no better than most mosquitos at discussing spin statistics in general, let alone a particular boson.

No 60-day old humans are better than any mosquitos at discussing science in general, let alone spin statistics.

*and I am fortunate to have been in the sort of study groups where, when one young lady uttered "*sigh*" another immediately responded with "sigh star!"

I share your jadedness, but humans at least have the potential to do so, a mosquito is several orders of magnitude away from that. I still have hope that humans can change, mosquitos will never change their behavior.

How do you know mosquitoes never change their behavior?

Last 50 million years. Maybe it’s a freak Poisson distribution tho and they suddenly grow massive brains in the next year

Not jaded, there are just much better ways to distinguish mosquitos and humans than a test which not only tests an accident, instead of an essence, but uses an accident that puts 100% (<1 million physicists/8b people ~= 0%) of humans on the mosquito side.

Some better triage methods:

  <= 500 g
  able to fly unaided
  can navigate by shallow CO2 gradient

Man I’m in awe with everything nature produced and think our life is so disconnected from the real world, but there’s tons of other metrics upon which we beat mosquitoes. It’s not like mosquitoes choose to be in equilibrium with nature, reducing any pressures that contain them they’d happily suck the world dry and then die out last

Are you really trying to argue with a hacker news poster that people are smarter than mosquitos?

One more proof of how weird and unique humans and their behavior are

What Freetail do you think humans are doing?

Look at yourself importance! So what? It’s different, but is it special? What do you know about the consciousness of a mosquito? Nothing! Because you’re not a mosquito! For all we know, they could be saying the same things about themselves as we are saying, about ourselves, that we are somehow special.

We on on the brink of world war and climate collapse and what role did the mosquito play in this? For we know the mosquitoes have gone past comprehending what a Hicks bozon is and decided it’s much easier to forget about it all and just suck our blood as we continue to overpopulate the planet.

Ok I’ve had my fill of internet contrarian philosophers to continue this conversation. If anything were life’s only chance of escaping the death of our star

Again, assuming life only exists on earth. You do not care about humanity, you are afraid of your own mortality so you create these science fictions.

I don’t and am not. But suggesting that mosquitoes communicate about purpose and mortality is silly

You’re not a mosquito so you don’t know. You can’t talk to mosquitoes so you don’t know. That’s a scientific fact.

It’s a creature with 200,000 neurons

OP said nothing about human-level intelligence being important - just that this may mean it's rarer than previously thought.

Seems like you've got an axe to grind, badly enough you go after it where it isn't.

Rare compared to what? We don’t even know what mosquito cognition is so how can we say whether that’s rare in the universe or not? Do you know what it’s like to be a mosquito?

I get the down votes on the previous comment, though, The bias that humans are somehow special and important is so strong it’s hard for us to acknowledge. And I can link that feeling of specialist to the destruction of the environment. And to climate change.

And because I have a different viewpoint than the majority of people here on our existence, does not mean I have an ax to grind, it just means I have a different opinion.

But also it tells us that it takes really long time to develop intelligence. Let's say it takes 10 billion years on average to develop intelligence and we are an early outlier. What we see now is exactly what would be seen by an early outlier.

Intelligence isn’t inevitable nor is it a sure bet to be kept around long term. Its just another phenotype.

It might not even be that good at being an evolutionary advantage. If intelligent life regularly ruins itself within a few tens of thousands of years, then we are nothing more than a strange blip on the timeline.

Which, IMHO, increases the estimated recovery time for burning all of the fossilized fuel.

I see your sentiment, but the logic is a bit flawed. When we drill for hydrocarbons, we have good understanding of the geology of the reservoir; we know what geologic era during which the deposits formed. Finding a bunch of new evidence for Precambrian photosynthesis is great, but it doesn't in any way imply that the bulk of the oil we produce is any older than we already know it to be. Very few precambrian deposits have ever been discovered or produced, though they most certainly are around. My understanding is a lot of the hydrocarbons from that time are thought to have been converted to bitumen and the like.

Not that any of this has any particular relevance. IMO humans have no business trying to plan for things on geologic timescales at this point in our development. Our governments struggle to forecast and act upon 10-20 year time horizons as it is.

I absolutely take your point, and I considered it before posting. But how long it take to evolve precisely the right conditions to create this reservoir-building machine?

> But how long it take to evolve precisely the right conditions to create this reservoir-building machine?

I dont understand the nature of your question. A planet with carbon based life is a reservoir building machine. If you take environmentally available carbon and transform it into fantastically complex molecules through the miracle of biology, these molecules will eventually be buried and break down into a sludge of simpler molecules. The answer to your question here on earth is that as long as there is carbon based life, hydrocarbons in the geology are inevitable.

One thing I always despise about science textbooks Is that they always state theories as facts rather than current theory.

Biology textbook should’ve say “As of today we think that photosynthesis started at so and so date.”

This would do more for science than anything else.

This is a big issue with the "science says ..." attitude that some people have, particularly people who believe themselves to be clever but have no experience actually doing anything resembling science.

I'm not just talking about the "trust the science" mantra that arose during Covid in response to politically-motivated conspiracy theories. That's one instance of a more general phenomenon.

We of course don't really know anything that happened billions of years ago. We have some good ideas about it, and data consistent with those ideas, and a lack of data inconsistent with those ideas. That's all we have, and that's all we will ever have. The ideas and data might improve over time (as well as things like computational techniques for using the data), but until we can actually travel back in time we can't ever know anything beyond that.

It would be better to teach readers that when scientists say a thing is so, it’s always prefaced with “to our current understanding…”

That saves an enormous load of weasel words, while also helping people understand what science actually is.

Edit:

Your comment rubbed me the wrong way, and I think I know why. It presumes people are too dumb to learn how to read things, but they’re not. Fantasy novels don’t preface every sentence like “in this fictional universe, Frodo handed the ring to Samwise. And then, for pretend, let’s say they ate some breakfast.” Readers would loathe that. Yes, we know this is all made-up. It’s a fictional work. It’s implicit in the name.

Well, science works are no different. “Science” implies “current understanding”. That’s fundamental to it. If we discover a better theory of something tomorrow, we’ll adopt future textbooks to describe that as our new model of that thing. You don’t need to weasel every sentence with “today, we think that…” because it’s implicit in the fact that it’s science writing, just like “it didn’t really happen” is implicit in fiction, and “as far as we know…” is implicit in a newspaper. Rather than “fix” those genres, we should educate people on how to read them.

> It presumes people are too dumb to learn how to read things, but they’re not.

Have you talked to average people, out of the HN bubble? They are often too dumb to read at all, period.

Miss me with that, dawg. We’re talking about people smart enough to be reading science content in the first place. Also, my dad was a mortician, and later an insurance salesman, and he’s perhaps the smartest person I’ve ever met. I promise you HN conversations are hardly the pinnacle of intelligent human discourse.

People are objectively not “often” unable to read. Literacy is extremely high, almost universal, in modern developed nations

But then when scientist say "there is 99% chance that asteroid will hit", the other characters says "so there is some wiggle room, lets call it 60% and move on".

Some people need to understand science is never exact. Like you are saying, they should understand it isn't exact.

Then others are like, since it isn't exact, then it isn't real.

I've heard arguments that since Climate Models have some range of error, then it isn't real, "see, there is some uncertainty". Climate change isn't real, because the models have some error. So for these people you need to be more forcefully confident in the predictions since they can't handle the nuance in discussing error ranges.

Alright, I see what you’re saying there, and agree with the premise. I think the right way to fix it is to tell people what science means, rather than re-write all science publications.

I would say we need to teach them about probability, statistics and risk assessment along with “science.”

but I disagree, by changing the wording we are implicitly teaching them what science means.

I think that's all under the science umbrella.

Thing is, changing the wording makes it more tedious to consume for more knowledgeable readers. It's not like we can tweak a few phrases to make it universally better with no drawbacks.

What do you mean by more forcefully confident? Do you mean pretending there's no uncertainty? That will only work as long as every result matches its probable prediction. One can be forcefully confident while acknowledging uncertainty. https://www.goodreads.com/quotes/344623-i-know-what-you-re-t...

If something is 99.9% Certain, then act like it is Certain.

Lot of pedantic STEM people will waffle and be like, "yeah, it isn't 100%, I can't commit", or "I'm not 100% confident".

Then the non-STEM run with it and say it isn't going to happen. "Well, they didn't seem that concerned".

I almost agree with you. However, I’m being a history teacher I’ve discovered that a lot of history books should have been fiction books because they deliberately tried to mislead us and act as propaganda. So the implication does not always match the intent.

Adding the qualification bring some honesty to the writer for the reader. There was a lot of discussion around Covid that was shut down, because people were assuming that the science was, in fact, a truth, and not a theory or even a hypothesis.

Especially for history textbooks. Some of the facts we have tons of evidence for, but others might be known just from a single inscription on a stone somewhere, but both are presented in the same way.

I agree with your sentiment but the article is badly written and misleading. It's not really controversial that there was photosynthesis at the time, it's regarded as widely accepted fact among experts. Also even before the GOE, there was likely anoxygenic photosynthesis, which still exists today in some very primitive organisms. I'm not sure if there's fossil evidence for those going all the way back but to be honest some of that science is questionable to begin with. We're talking about extremely small particles they claim to identify as fossilized bacteria.

There are stromatolite colonies that still exist today, in Australia for example. When students are taught about the history of earth, they're taught such cyanobacteria were among the first if not THE first to produce oxygen en masse through photosynthesis. This was never based on fossil finds but on other evidence. So the paper isn't anything groundbreaking, it's another piece in the puzzle if we accept their images show fossilized thylakoids.

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