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by jonplackett 1106 days ago
Weirdly, there was actually a period of history where this was normal.

During the Carboniferous period 300 million years ago trees just fell over and lay there because nothing had evolved to decay them yet.

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

4 comments

That didn't sound too right for me (but my biology knowledge is dated at this point) so I read the relevant section from that page. It concludes wiht:

"""The delayed fungal evolution hypothesis is controversial, however, and has been challenged by other researchers, who conclude that a combination of vast depositional systems present on the continents during the formation of Pangaea and widespread humid, tropical conditions were responsible for the high rate of coal formation."""

It's interesting to think just how much went on before trees with lignin showed up. Flowers are also relatively recent - 150mya.

Yeah the snippet of the wikipedia page that you link is citing the paper that put the final blow to the fungal lignin breakdown hypothesis. It points out (the last point is particularly strong):

* there is evidence for partial lignin breakdown in existing deposits, so we know it was a thing back then

* if it were just lignin breakdown, then we'd see orders of magnitude more deposits. that is, if you look at the per year deposit rate, you'll see only a small fraction of lignin being deposited.

* a large fraction of deposits doesn't even contain lignin, often below or above deposits with lignin, but without there being a different rate of depositions between them.

(copying my earlier comment https://news.ycombinator.com/item?id=34654837 )

In general, it's mind-blowing to travel back in Earth's history and realize there were tens or hundreds of millions of years where strategies that are commonplace today had never been tried before (or they'd tried too early and failed). It makes one wonder, what will be the strategies of future life which no creature has yet evolved? Can we even imagine it?
I think it's almost guaranteed that bacteria eating plastics will proliferate globally at some point, we've put so much of this stuff in the environment and it's just free energy ready to be consumed if your digestive system knows how.
And suddenly plastics won't be the sterile, durable wonders that they are. We are living in The golden age of plastics, folks.
Things degrade wood too, doesn't make it useless.
Wood in today's society needs chemical treatment or physical isolation before we use it a construction material.
Wood is useless for sterile applications because it harbors bacteria and such. Think dentist, doctor, chemistry labs, industrial processes, food manufacturing and packaging, chemical storage, etc etc. All Plastic.
I don't think they'll get through metal and certainly not glass for a long time.
I think metal is already a target of microbial corrosion:

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

I've definitely already heard of plastic-eating bacteria. They already have bugs eating it now too

https://www.theguardian.com/environment/2021/dec/14/bugs-acr...

I used to entertain this idea but I'm somewhat skeptical such a thing could proliferate, there is just not that much plastic relative to the other sources of energy an animal can evolve towards. I'd be interested to hear otherwise though.
There is tons if it some places though
You don't need a ton everywhere. You just need enough in a few places for long enough.
Where did the Tupperware go?!

Will we have to develop antibacterial plastics to combat this for stuff we don’t want eaten, yet?

Funny. Just the other day I read an article about where Tupperware has gone.

https://text.npr.org/2023/06/01/1178876648/tupperware-busine...

Maybe we can just add some broad-spectrum antibiotics into the standard plastic mix.
And make all bacteria known to men immune?
Check out cronenberg's recent movie, crimes of the future, seems relevant haha
it's also mind blowing to know that there are things which really haven't changed in over a billion years, yet still do just fine. How did my bio prof say it? "Bacteria are like the race cars of the biological world. They don't win by having the best strategy, they win by rate of duplication and acquisition."
Clearly I don't know much about race cars because that makes no sense to me, lol
I should have mentioned he was an F1 fan.
Are there species of bacteria that are substantially unchanged in a billion years?
Morphologies of cyanobacteria show that fossils from billion+ years ago show little change. https://en.wikipedia.org/wiki/Stromatolite
No way to know for sure. But many bacteria today look very similar to what little bit of maybe fossils we might have.
Natural selection are now slower than artificial ones except on the microbial levels.

So maybe extinctions after extinctions for animals that are visible to us, and then bunch of new superbugs.

And grass is even younger - just ~100-65mya! (depending on the source - not sure if it's narrowed down in papers)
This is good news. The idea of the delayed fungal evolution hypothesis was this:

"Before trees grew wood that was unable to rot and so became coal but after fungus came now wood is ruined and it's impossible to make coal again."

Understanding that coal formation is a reversible process and that a new agent didn't permanently ruin the process, is a sigh of relief.

So coal is actually renewable?
On multi-hundred million year timespans.
You know it would be very cool if someone made an UE5 demo that was just a forest with a dozen or so options to change the date and see which types of vegetation appear and disappear.
Presumably flowers proliferated due to insect pollinators?
Did they make big fallen tree piles? What a time that could have been for any species interested in burrows, bushwhacking, or forts.
My brain loves to pretend that this is what happened for millions of years, but the truth is that it turns into dust and "dirt." Things still weather and get broken. Even stone turns to sand. But it takes longer than we're currently used to and the particles don't get processed. But this same event that the parent linked led to all our coal as well as an important niche that modern fungi hold today (they existed back then, but couldn't process the lignin. Interesting thing, there's a term called "evolutionary radiation" and this was one of the largest periods of time for this, but it is not related to the radiation in the context of Chernobyl.
Isn't that the major origin of coal deposits?
And when that huge pile of trees finally started to burn, we got our first case of rapid global warming from burned carbon. The second one is done by humans right now.
Actually, burning of trees helped reduce CO2 over the long term. That's because burning is incomplete and produces charcoal. Charcoal doesn't decay, so when it is buried it semi-permanently takes carbon out of the biosphere. Over extended time, this would draw down atmospheric CO2. Some coal deposits from that period have a significant fraction of charcoal in them.
IIRC, that's lignite coal?
I don't think so? The charcoal would remain identifiable as the coal is matured by burial and heating (perhaps not all the way to anthracite).
Ah true. It'd be more of a structural thing I guess.
This doesn’t sound right. Iirc there have been many periods in earth’s history warmer than today, and carbon was part of the climate feedback for all of them, but this is the first time that warming is coming from direct forcing via co2.
This is definitely not the first time temperatures have risen due to direct co2 levels. Last time was only about 3 million years ago.
Are you sure? Because my understanding is, in the past what has happened is that some other force causes a bit of warming, and then the oceans heat up, which causes co2 to bubble out, which then causes more warming, which causes more co2 to bubble out, and so on. So co2 is an active part of the picture but it wasn’t the independent variable, so to speak. Whereas now we’re mining fossil carbon and squirting it directly into the atmosphere, which is new.

And climate scientists are very smart and have worked out how much the added co2 amplified the original warming, and have been able to work out how much warming you would get by doubling co2 levels, which appears to be around 3 degrees C.

It’s very similar. We’re just the ‘other force’ that is kicking it off this time, and we’re a bit more efficient than most.
Hmm, I don’t think you read what I wrote very carefully. I’m making a very specific and rather technical point about the feedback loops in the climate.

Basically the amount of co2 that the ocean can have dissolved in it is a function of temperature and the relative co2 concentration of the air. When the temperature of the water increases it can hold less co2. Just like when soda gets warm and isn’t pressurized, it gets flat.