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I'm fascinated by this. It took 60 million years after trees evolved for microbes to evolve that could digest them[1]. The resulting strata of undigested tree a
by fredley 9y ago
I'm fascinated by this. It took 60 million years after trees evolved for microbes to evolve that could digest them[1]. The resulting strata of undigested tree are now most of our coal. Now of course, if a tree dies and is left where it fell, it is usually digested entirely in a number of years by microbial life.
What would happen if a microbe evolved that could feed itself from plastic? And what if it got out of the lab? Imagine all the plastic items in the World suddenly as susceptible to rot as wood. It would fundamentally change almost every aspect our existence, in a very short amount of time.
[1]: http://phenomena.nationalgeographic.com/2016/01/07/the-fantastically-strange-origin-of-most-coal-on-earth/ http://phenomena.nationalgeographic.com/2016/01/07/the-fanta...
- k_ 9y agoIt would be awesome if we could unleash something like this in our oceans without doing harm to the ecosystem (would be hard to do more harm that what we are already doing with plastic, but still).
- spodek 9y agoIt would be awesome if we ourselves could interact with the ocean without doing harm to the ecosystem.
- uhhyeahdude 9y agoYes, yes it would. Systems thinking is hard. (Eco)Systems thinking is nearly maddening. Even if one could account for many variables (for an acceptable value of many), one would still have to deal with everything else, which often includes stupidity, irrationality, politics, emotion, villains... Nature makes many errors, but at least it isn't stupid; those errors result in the adaptations that make the world work. This process involves a lot of death, but it works. Or, it did. I am somewhat familiar with ecosystems and environmental restoration, and I don't mean to discourage anyone from positive thinking; in this case, however, I really think people need to try to comprehend the mechanisms before experimenting. I reiterate: systems thinking is hard.
- meric 9y agoThe best way to unleash it in our system without doing harm to the ecosystem is to be patient. There is energy content in the plastic and over 100-200 million years the chance is extremely high Earth’s ecosystem will adapt to the abundance of plastic.
- jon_richards 9y agoThe issue has never been whether the ecosystem will adapt. It has been how well we will. If plastic in the ocean kills/renders toxic all the fish, that will be an issue for us. The ecosystem? It will be fine.
- kjjw 9y agoThe idea that ecosystems are self balacning and always bounce back is discredited science. It’s still a popular idea in mainstream discussion, though.
- deleted 9y ago[deleted]
- 3chelon 9y agoIs it really discredited? What are your sources? I tend to believe (with no actual evidence, since there is none), that the ecosystem will adapt to whatever damage we do to it using the tried-and-tested method of natural selection. Most mainstream conversations about this are entirely anthropocentric and assume we have to be part of that equation. They always assume we're the top of the food chain. But whereas most of us will never be eaten by a tiger, pretty much all of us will be eaten by bacteria one day. Microbial life has been around for far longer, and is far more abundant than we can ever hope to be. I don't think much we can do will fundamentally alter that balance.
- foota 9y agoIt's a hyperbolic example, but I doubt life on Earth would adapt to being engulfed by the sun, for one
- endymi0n 9y agoI had the same exciting thought before it dawned on me that we usually choose plastics for a reason. Imagine water bottles breaking down in the store. Imagine protective coatings of ships breaking down. While I'd be happy for the mess we created in the oceans, I'm unsure if this would just trigger another arms race for more indestructible materials — that would clog the oceans once again.
- chiefalchemist 9y agoWe chose plastics because it was cheaper. Yes, there are other benefits. Unfortunately, no one asked, "If this stuff doesn't decompose, then what?" to assess that risk vs the benefits. Without that answer the use of plastics should have been mitigated a la nuclear fission. Instead, micro bits of plastics are everywhere; the oceans and their ecoayatem are compromised. Etc. For what? Convenience and a few cents?
- acdanger 9y agoI ask myself the same question about our current techno-commercial landscape.
- spodek 9y agoThe main reason is not having to account for externalities. As long as someone else has to pay for cleaning up, why bother thinking about it when you can keep the short-term profits?
- fredley 9y agoMy favourite what if: What if we engineer such bacteria to survive in our gut?
- pbhjpbhj 9y agoManufacturers don't really choose plastic for longevity, they choose it because it's cheap and easy to work with (ie plastic [adjective]). There are already biodegradable alternatives for almost everything but they add a few pence to the cost of a happy meal, say, and aren't a strong enough differentiator at the point of sale for profit-driven companies to care about it. The alternatives don't instantaneously degrade, they usually need proper composting to quickly degrade (high temperatures, aerobic). We've used compostable nappies that when properly composted can degrade fully in a year - they're similar in use (save not releasing "gel balls"), don't appear to have a significantly depleted shelf-life. I don't know why such things aren't mandated TBH.
- Orphis 9y agoAbout 20 years ago, I did a one week internship as a teenager in some lab that worked exactly on this. They were trying to grow and select enzymes that could process different types of oil that frequently occurred in spills. The tricky part was to make sure they only targeted what was in the ocean. You didn't want them to start propagating into the oil tanks in boats, or start processing all the random plastics that make up boats or various infrastructure. I remember on my last day, they had some really good results with some samples that processed some oil really well and were quite excited. I then left, and have no idea if they managed to reproduce the results or not.
- JulianMorrison 9y agoMeh, make them eat all the oil. Civilization could use the kick in the ass to switch to electrics.
- majewsky 9y agoWhen they eat the oil, how do they metabolize it? If they end up producing CO2 like ICEs do, that would not be a productive measure against climate change at all.
- JulianMorrison 9y agoGiven it was going to be burned, that's six of one and half a dozen of the other, except that if the bugs eat it, the humans have to change their behaviour.
- simias 9y agoPlastic pollution has tons of drawbacks but at least it doesn't contribute to global warming since it effectively stores carbon. Having all the plastic in the world start rotting away and releasing carbon into the atmosphere might to a lot of harm. Especially if other petrol byproducts like the bitumen of our roads are concerned. You're right however that if these products start becoming effectively unusable (or less usable) because they now rot it would make alternative solutions a lot more attractive, but we already have so much petrol byproducts in the wild that the transition would be pretty nasty.
- neolefty 9y agoThe organisms would probably need micronutrients as well, such as iron or copper. Advantage: We can control their spread—target them at the Garbage Patches Disadvantage: More expensive to deploy, since you have to also sprinkle fertilizer for the cleanup to be effective.
- Hoasi 9y agoThis could be a great plot for a sci-fi novel.
- adrianN 9y agoIt's been done at least once: https://en.wikipedia.org/wiki/Earth_Maiden_Arjuna https://en.wikipedia.org/wiki/Earth_Maiden_Arjuna
- King-Aaron 9y agoSee also Larry Niven's Ringworld https://en.wikipedia.org/wiki/Ringworld https://en.wikipedia.org/wiki/Ringworld
- fredley 9y agoI've tried to write some short stories on the theme but I'm no writer, I could never get something I was happy with.
- campbellmorgan 9y ago>I could never get something I was happy with You sound like a writer! Keep going
- cooperadymas 9y agoPossibly a slight spoiler, but Andromeda Strain does exactly this. https://en.wikipedia.org/wiki/The_Andromeda_Strain https://en.wikipedia.org/wiki/The_Andromeda_Strain
- JohnL4 9y agoClots blood and eats rubber, but ok.
- adrianN 9y agoWe build lots of durable structures out of wood. I don't think it would be a very serious problem.
- mkj 9y agoLots of modern construction wood is laminated together with plastic. I'm sure people would adapt though.
- vanderZwan 9y agoI expect this would also make the material scientists happy for being given a new challenge.
- sohkamyung 9y agoThe article only mentions the enzyme breaking down polyethylene terephthalate (PET), not other kinds of plastics. So those would be safe from the enzyme. Of course, the enzyme could be engineered to break down all kinds of plastics but I doubt that is biologically possible. It would become like the old joke of the 'acid that can dissolve anything', at which point the question becomes, "So what do you use to contain the acid?" :-)
- TeMPOraL 9y ago> It would become like the old joke of the 'acid that can dissolve anything', at which point the question becomes, "So what do you use to contain the acid?" :-) Tangential: not an acid, but antimatter has similar properties, and you contain it in a magnetic trap ;).
- sohkamyung 9y agoI think not. Magnetic traps can only contain anti-matter ions, not neutral anti-matter atoms or molecules.
- TeMPOraL 9y agoJust a shorthand. Ions are good enough to... dissolve regular matter. Into gamma rays.
- rflrob 9y agoYou can actually use multipole magnets to capture neutral anti-hydrogen. Not that they're trapping a lot of neutral anti-hydrogen, but some. [1] https://en.wikipedia.org/wiki/Antihydrogen#Low-energy_antihydrogen https://en.wikipedia.org/wiki/Antihydrogen#Low-energy_antihy...
- sohkamyung 9y agoThanks for that. I forgot about the spin magnetic moment. Whether this works on other atoms or molecules depends, of course, on how strong this field is.
- lawlessone 9y ago>What would happen if a microbe evolved that could feed itself from plastic? it did. also plastic degrades in UV light and due to weather so it probably wouldn't be that much different to now.
- raverbashing 9y agoInteresting paradox. Either making cellulose is easier than breaking it up (even under the sun/rain/etc) or maybe bacteria "didn't see a reason" to tap that energy source (hence not evolving in that direction).
- m12k 9y agoOr maybe it required a leap of evolution in a direction in which there was no other evolutionary pressure to take the first steps and make subsequent steps smaller and thus more likely? Complex mutations are probably more rare if the environment does not facilitate doing it bit by bit.
- qbrass 9y agoCellulose was hard to break down, so when bacteria found a way to do it, they had no competition for that food source and millions of years worth of it just sitting around to feed on.
- eojrgherkghj 9y agoIt's not so much the cellulose, it's the lignin that makes wood so hard to digest. Fungi resort to producing peroxides instead of attacking it directly with tailored enzymes
- klmr 9y agoThere is no paradox: Plastics have really only been around for less than a century. Modern plastics are all synthetic, and sufficiently distinct to all naturally occurring biopolymers. So bacteria only had ~100 years to evolve this capability. Compare this to the ~60 million years it took to evolve wood-digesting enzymes efficiently. The situation isn’t entirely comparable, since these enzymes wouldn’t have to evolve “from scratch”. Hence why researchers may have found rudimentary capabilities in the wild. But evolving this from the basics to an efficient food source naturally would take a very long time indeed.
- akavel 9y agoUm, the article does actually explicitly mention such a microbe, as that is the origin of the titular enzyme! Do I misunderstand something, or you didn't read the article? It's hard for me to understand the "What would happen if a microbe evolved..." question when the article literally says: "[The] PETase [enzyme] is secreted by a plastic-munching bacterium called Ideonella sakaiensis 201-F6. This bug was discovered in 2016 at a PET-bottle recycling plant in Sakai, Japan."
- sarabande 9y agoI think a more charitable interpretation of the parent comment was that of a doomsday thought experiment/rhetorical question: What would happen if these bacteria evolved to really be able to cause damage one day? The article only briefly remarks: > If these hurdles can be surmounted, though, PETase might make a dent in the scourge of plastic waste.
- goodmachine 9y agoFWIW, this 'doomsday scenario' is roughly the plot of a 1979 Judge Dredd episode (which I remember fondly) - featuring a world in which support bridges were made of 'plasteen' under attack from a novel bacterium: SOMETHING'S EATING IT AWAY The Great Plasteen Disaster https://dreddalert.blogspot.co.uk/2014/01/judge-dredd-great-plasteen-disaster.html https://dreddalert.blogspot.co.uk/2014/01/judge-dredd-great-...
- JohnL4 9y agoAlso, a book published in 1972, _Mutant 59: The Plastic Eaters_. https://www.goodreads.com/book/show/2368220.Mutant_59 https://www.goodreads.com/book/show/2368220.Mutant_59
- cavanasm 9y agoAlso (sort of) the crux of one of my favorite horror manga, Biomeat: Nectar, which is about a genetically engineered animal that eats "garbage" (basically anything but metal, glass, and stone IIRC) and can be harvested for food, but escapes from the garbage plants and starts going after people. They're not microbes though, but more like nightmare fuel looking bugs about the size of a face, with the mouth on the bottom, and they reproduce via budding (like a hydra).
- mseebach 9y ago> Imagine all the plastic items in the World suddenly as susceptible to rot as wood. It would fundamentally change almost every aspect our existence, in a very short amount of time. Hardly. Some usages of plastic would need to be altered, but most would be fine. The conditions in which wood will rot are very specific (the forest floor, basically) and reasonably easy to avoid, surely something similar will be true for rotting plastic. Pre plastics, practically anything, including all kinds of liquids, was stored in wooden barrels.
- Sharlin 9y agoTo be fair, wooden things—were they barrels, ships, or houses—absolutely require protection and maintenance to prevent them from rotting. We became pretty good at that because wood was a crucial raw material for millennia. We haven’t thought about how to protect plastics because we’ve accustomed to plastics not needing protection.
- Moru 9y agoPlastics need protection from a lot of things, cold, heat, sun not to mention physical wear. Some older, cheaper plastics just crubles to dust when you touch them.
- therealdrag0 9y agoIs crumbled plastic part of the micro-plastics we hear about polluting the ocean?
- Kroniker 9y agoYes! In fact most plastic is relative susceptible to UV radiation, which facilitates that "crumbliness" in the ocean.
- kazinator 9y agoThe conditions under which wood rots: untreated + outdoors.
- georgecmu 9y agoThat's a cute story, but the evidence is lacking. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4780611/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4780611/ The Carboniferous−Permian marks the greatest coal-forming interval in Earth’s history, contributing to glaciation and uniquely high oxygen concentrations at the time and fueling the modern Industrial Revolution. This peak in coal deposition is frequently attributed to an evolutionary lag between plant synthesis of the recalcitrant biopolymer lignin and fungal capacities for lignin degradation, resulting in massive accumulation of plant debris. Here, we demonstrate that lignin was of secondary importance in many floras and that shifts in lignin abundance had no obvious impact on coal formation. Evidence for lignin degradation—including fungal—was ubiquitous, and absence of lignin decay would have profoundly disrupted the carbon cycle. Instead, coal accumulation patterns implicate a unique combination of climate and tectonics during Pangea formation. from another article: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4780642/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4780642/ There is a long-invoked but incorrect (9) perception that lycopsid-dominated forests were the main source vegetation of Carboniferous coals because of the abundance and resistance to decomposition of lycopsid periderm (bark) (e.g., refs. 1, 4, and 5). Thus, lycopsid dominance supposedly was essential for formation of the economically important Carboniferous coals. In what initially appears to support this perception, Nelsen et al. (8) use spatiotemporal trends in Phanerozoic organic-rich terrestrial sediments to demonstrate peak North American coal production during intervals when lycopsids dominated Euramerican tropical forests. Most dominant Carboniferous wetland plants, however, produced little wood, and the arborescent lycopsids were no exception (10). The towering lycopsid stature was made possible by unlignified periderm rather than lignin-rich wood. Therefore, they contributed less lignin to peat accumulations than woody plants, which were episodically abundant, although rarely dominant, in Pennsylvanian–early Permian tropical lowland basins (9, 11). Nelsen et al.’s (8) scientific twist to the hypothesized lycopsid–lignin–coal linkage—that is, documenting coincidence in peak coal production and lycopsid dominance, when lignin would have contributed minimally to peat accumulation—weakens the argument that the emergence of lignin synthesis was one criteria for intensified terrestrial organic carbon sequestration in the Carboniferous. Large-scale peat accumulation further requires suppression of organic matter decay, of which woody tissue, in the absence of efficient lignin-degrading fungi, has been considered the source (5). Nelsen et al. (8) challenge this view by documenting fungal and bacterial degradation of Paleozoic lignified tissues and, conversely, evidence for abundant unlignified organic matter in many peats. Nelson et al.’s study, building on decades of paleobotanical research, thus unequivocally demonstrates that pre-Permian lignin resistance to decay, and thus preferential biochemical composition of vegetation, was not the key to high rates of peat accumulation 325–300 Myr ago. Intriguingly, lignin’s legacy in Carboniferous peat accumulation may be moot: Nelsen et al. (8) point out that the evolution of Agaricomycetes fungi, based on reassessment of phylogenomic evidence (7), is permissible as far back as the Devonian (420–359 Myr), thus potentially closing the evolutionary lignin–fungal gap. If correct, then a closer temporal association between the onset of lignin biosynthesis and the evolution of lignin-degrading fungi suggests rapid evolutionary innovation in response to a novel resource. Nelsen et al.’s collective findings (8) further resolve a mass balance conundrum regarding the Carboniferous–Permian atmosphere. In a world with hypothesized abundant lignin, the absence of fungal-mediated degradation, in concert with widespread peat accumulation and burial, would have depleted atmospheric CO2 within a fraction of the proposed ∼120 Myr evolutionary gap. Large-magnitude CO2 degassing from volcanism, for which there is no clear evidence, would be needed to maintain the requisite long-term balance in total CO2 inputs and outputs to and from the atmosphere (1).
- devy 9y ago> Imagine all the plastic items in the World suddenly as susceptible to rot as wood. It would fundamentally change almost every aspect our existence, in a very short amount of time. Absolutely! The first thing came to my mind is the usage of polymers in construction industry (epoxy for joining material, coating for anti-corrosion measures) and the predominant PVC underground sewer lines and plumbing pipes. If those aren't as durable as we previously assumed, the rebuild/replacement is going to be catastrophic. (PS: I had almost had to replace the underground clay/cast iron sewer lines that's been there for 50 years and reaching the end of life for the material at our new home last year. The cost was astronomical and requires many town permits and time to even start the project. Thankfully we didn't have to!)
- dv_dt 9y agoIt's an interesting thought, but perhaps we should consider how susceptible we would actually be. We still build houses from wood, which can rot and be digested, but generally doesn't with a reasonable amount of maintenance. Even if an hyper effective microbe were to spread, the manner of spread is unlikely to be any more effective with respect to dispersion than others that e.g. attack wood.
- vanderZwan 9y ago> It took 60 million years after trees evolved for microbes to evolve that could digest them Go back further in time, and you'll discover that from the moment photosynthesis arrived on the scene and took over as an energy source, until a life-form evolved that could make use of the poisonous oxygen that was a byproduct of it, it took roughly 0.7 billion years[0]. Resulting in many, many cyanobacterial apocalypses in that time. We may have to come up with new (old) material solutions to many things, but on the whole I think that plastic-eating microbes are probably more of an apocalypse-averting scenario than an apocalypse-causing one. EDIT: to put that 0.7 billion years number into perspective, let's look at the age of life on Earth: > The earliest time that life forms first appeared on Earth is unknown. They may have lived earlier than 3.77 billion years ago, possibly as early as 4.28 billion years ago, not long after the oceans formed 4.41 billion years ago, and not long after the formation of the Earth 4.54 billion years ago. The earliest direct evidence of life on Earth are fossils of microorganisms permineralized in 3.465-billion-year-old Australian Apex chert rocks. Sticking to the confirmed existence of life, 0.7 billion years represents 20% of life's history on this planet. With conservative estimates 18%, and assuming it was there from very early on, 16%. Even if life has existed on this planet for as long as Earth itself has, then this still accounts for 15% of the history of life on this planet. Meanwhile, we likely split off from Chimpanzees around 12 million years ago, with modern humans not evolving until about 300-200 thousand years ago (which I still find mind-bogglingly recent), which is somewhere between 0.006 to 0.008%[3]. EDIT2: This makes me wonder if modern bacterial life-forms, if not all modern life-forms that we may consider simple and primitive, may not in fact be incredibly sophisticated compared to their ancestors of billions of years ago. I can imagine that they appear similar due to a particular solution already being stuck in a local optimum (say, shark body plans, or certain leaf shapes) but that on the genetic level the more recent life-forms might have evolved complicated systems of evolvability itself that lets them adapt much faster than before[4]. [0] http://www.patheos.com/blogs/daylightatheism/2009/02/bands-of-iron/ http://www.patheos.com/blogs/daylightatheism/2009/02/bands-o... [1] https://en.wikipedia.org/wiki/Earliest_known_life_forms https://en.wikipedia.org/wiki/Earliest_known_life_forms [2] https://en.wikipedia.org/wiki/Chimpanzee%E2%80%93human_last_common_ancestor#Current_estimates https://en.wikipedia.org/wiki/Chimpanzee%E2%80%93human_last_... [3] https://en.wikipedia.org/wiki/Timeline_of_human_evolution#Homo https://en.wikipedia.org/wiki/Timeline_of_human_evolution#Ho... [4] https://en.wikipedia.org/wiki/Evolvability https://en.wikipedia.org/wiki/Evolvability