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Mirror Life Worries science.org

stiiv3 hours ago

For a great sci-fi treatment of the dangers of mirror life, see Fantastic Four 5-6 (2023) by Ryan North. Yes, that Ryan North, and no, it's not your "typical" comic book.

pavel_lishinan hour ago

I've heard that his Hulk run is also excellent.

Anyway, Peter Watts' Rifters series is another excellent take on the genre, although it's not mirror life per se. (And it's ... not a happy read.)

hermitcrab3 hours ago

Question to any biologists. Do we need to worry about mirror viruses or just mirror bacteria?

Thorondor3 hours ago

A mirror virus would not be able to infect normal cells. Viruses depend on (chiral) host cell machinery such as ribosomes to reproduce.

nakedrobot25 hours ago

Please future humans, do not build mirror life.

Thanks.

card_zero5 hours ago

From the point of view of a newly created colony of opposite-handed bacteria, it would be facing an entire planet of really well established mirror life.

stravant4 hours ago

Ever heard of invasive species?

That's the problem. Mirror life may not be a problem for the biosphere in the long run but it could totally be a problem for humans in the short run.

gus_massa4 hours ago

Mirror species can eat the local species, so they have it easy.

Mirror life can only use the fats and a few amino acids of the normal life. All sugars have chirality so they would need some enzymes to east their own mirrored sugars and another set of enzymes to eat normal sugars. Also, most amino acids have chirality and they would have to reverse them or make their own.

So even if someone waste a few gazillions dollars to make mirror life, it would not be able to eat most normal food.

jlokier4 hours ago

> All sugars have chirality so they would need some enzymes to eat their own mirrored sugars and another set of enzymes to eat normal sugars.

Until mirrored life evolves enzymes to eat non-mirrored sugars, mirrored life will be at a large disadvantage.

But with exposure to our environment, replete with non-mirrored sugars, that sets up a large evolutionary pressure in the direction of finding those enzymes, in addition to the mirrored enzymes they will already have for eating mirrored sugars.

With such evolutionary pressure, it seems plausible mirrored life will evolve those enzymes, even though non-mirrored life appears not to have done so, or at least not retained it. Because there has been no equivalent evolutionary pressure for non-mirrored life to eat mirrored sugars.

If mirrored life does evolve those enzymes, due to that asymmetric evolutionary pressure, then instead of being at a disadvantage, it might give them a temporary advantage over non-mirrored life.

jlokier4 hours ago

[flagged]

blibble5 hours ago

yes it seems unlikely that it would be able to outcompete everything already on earth

if it did I would have thought it would have appeared in the past 5 billion years or so

Symmetryan hour ago

Cyanobacteria reproduce rapidly in sunlight and their numbers are mostly kept in check by viruses. If you bred a species that didn't have any existing viruses there would still be amoebas, flagellates, etc which would use the extra food to reproduced faster and keep the numbers in check, though it would be a big ecological problem. If these couldn't eat them because the new cyanobacteria was mirror life they they'd lock huge amount of carbon from the biosphere as indigestible sugars and starving all other plant life, over the course of maybe a year at the most.

It's possible that humanity could survive by exploiting things like fossil fuels but by default it would be as bad as the extinction that ended the Permian. And certainly most humans would die.

We're protected from this naturally because it takes over a billion years to evolve something as good at reproducing as cyanobacteria from scratch and any biogenisis that were to happen in the modern world would produce something so hapless it would be swiftly out competed for resources. You can't evolve from a regular bacteria to a mirror bacteria, evolution is really bad at making multiple changes at once and this would require changing literally every part of an organism at once.

joecool10293 hours ago

There were large extinction events, prob most notable from this was the great oxygenation event that wiped out most anaerobic life. Other than that I can think of stuff like fungi evolving to break down cell walls.

ejstronge4 hours ago

> if it did I would have thought it would have appeared in the past 5 billion years or so

It may have appeared and been outcompeted. That doesn’t suggest its (artificial) reintroduction would again be outcompeted

XorNot4 hours ago

It does actually, because it implies it fought and lost that battle the first time.

Now, with L-amino life everywhere it would have an even bigger starting problem.

We see this with extremophiles: organisms which can grow in nuclear cooling ponds full extremely badly when transplanted to nutrient rich environments with other, less capable organisms.

clownpenis_fart4 hours ago

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ajuc5 hours ago

Hopefully mirror antibiotics are earlier in the tech tree than mirror life.

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