I never thought of mirror bacteria before, but now I think it may get even worse.
They will survive somewhere on Earth and then start evolving
Even if they cannot survive inside the human body (due to the adaptive immune system as J Bostock suggested), I strongly believe they can survive somewhere on Earth. This is because some bacteria photosynthesize their own energy and do not need chiral molecules from any other creature to survive. A mirror bacteria of them will have no disadvantages, but be completely safe from bacteriophages.
They may evolve poisons against lifeforms with the opposite chirality
They will adapt to normal life, and normal life will adapt to them, but large animals like humans evolve very slowly and won’t adapt to them fast enough.
As they compete against normal bacteria, fungi and protists, they might evolve various kinds of deadly poisons designed to kill all lifeforms with the opposite chirality. Microorganisms are known for using chemical warfare to kill their competitors: Penicillium fungi evolved penicillin in order to kill all kinds of bacteria. Penicillin only kills bacteria and does not hurt eukaryotes like fungi or humans. This way the Penicillium fungi avoids poisoning itself.
The mirror bacteria might evolve deadly poisons against all lifeforms with the opposite chirality, without having to worry about poisoning themselves due to the chirality difference. This lack of self-poisoning may allow the poisons evolve faster and be more potent. It’s very hard to evolve a new poison and evolve resistance to your own poison at the same time, because evolution cannot plan ahead. If a new poison attacks a fundamental part of all lifeforms, the organism making it will kill itself before it can evolve any resistance. Unless it’s one of the mirror bacteria.
Chiral molecules include the amino acids which make up all proteins, and the lipid bilayer which cover all cells, so the mirror bacteria’s poisons have an unprecedented range of potential targets.
If the mirror bacteria become extremely widespread, their “antimirroral” poisons designed to fight competing microbes may also become widespread, and kill humans as a side effect. As collateral damage.
Alternatively, they might also evolve to directly infect large animals and kill humans.
I think the poison scenario may be worse because they can kill from a distance. Even if you sanitize entire cities with mirror antibiotics, poison from outside might still arrive due to the wind. Anyone with allergies knows the air is filled with spores and other biology.
Optimism
We can prepare for the risk before it happens. Not only can we make mirror antibiotics but “antimirroral” chemicals much stronger and less specific than antibiotics, which targets all mirror proteins etc. Well adapted mirror bacteria may survive far higher concentrations of “antimirrorics” than humans, but humans can pump out far higher concentrations of “antimirrorics” than the mirror bacteria, so we may win the fight if we prepare.
I also like your space lab idea, it allows us to empirically test how dangerous mirror life is without actually risking extinction. Not all risks can be empirically tested like this.
If there is an equilibrium, It will probably be a world where half the bacteria is of each chirality. If there are bacteria of both kinds which can eat the opposite kind, then the more numerous bacteria will always replicate more slowly.
Eukaryotes evolve much more slowly, and would likely all be wiped out.
I don’t know about microscopic eukaryotes, but yes the risk is that slow-evolving life (like humans) may be wiped out.
I agree the equilibrium could be close to half mirror bacteria, though in my mind a 1:10 ratio is “close to half.” The minority chirality has various advantages. It is less vulnerable to bacteriophages (and possibly other predators). It encounters the majority chirality more frequently than the majority chirality encounters it. This means the majority chirality has very little evolutionary pressure to adapt against it, while it has lots of evolutionary pressure to adapt to the majority chirality. The minority chirality will likely produce “antimirrorics” much more, until the two sides balance out (within an environment).
It probably won’t be exactly half, because normal chirality life does start off with way more species. It might evolve better “antimirrorics” or better resistance to them. The mirror bacteria will lack the adaptions to survive in many environments, though if it evolves quickly it might survive in enough major environments to become a severe risk.
Why it may get even worse
I never thought of mirror bacteria before, but now I think it may get even worse.
They will survive somewhere on Earth and then start evolving
Even if they cannot survive inside the human body (due to the adaptive immune system as J Bostock suggested), I strongly believe they can survive somewhere on Earth. This is because some bacteria photosynthesize their own energy and do not need chiral molecules from any other creature to survive. A mirror bacteria of them will have no disadvantages, but be completely safe from bacteriophages.
They may evolve poisons against lifeforms with the opposite chirality
They will adapt to normal life, and normal life will adapt to them, but large animals like humans evolve very slowly and won’t adapt to them fast enough.
As they compete against normal bacteria, fungi and protists, they might evolve various kinds of deadly poisons designed to kill all lifeforms with the opposite chirality. Microorganisms are known for using chemical warfare to kill their competitors: Penicillium fungi evolved penicillin in order to kill all kinds of bacteria. Penicillin only kills bacteria and does not hurt eukaryotes like fungi or humans. This way the Penicillium fungi avoids poisoning itself.
The mirror bacteria might evolve deadly poisons against all lifeforms with the opposite chirality, without having to worry about poisoning themselves due to the chirality difference. This lack of self-poisoning may allow the poisons evolve faster and be more potent. It’s very hard to evolve a new poison and evolve resistance to your own poison at the same time, because evolution cannot plan ahead. If a new poison attacks a fundamental part of all lifeforms, the organism making it will kill itself before it can evolve any resistance. Unless it’s one of the mirror bacteria.
Chiral molecules include the amino acids which make up all proteins, and the lipid bilayer which cover all cells, so the mirror bacteria’s poisons have an unprecedented range of potential targets.
If the mirror bacteria become extremely widespread, their “antimirroral” poisons designed to fight competing microbes may also become widespread, and kill humans as a side effect. As collateral damage.
Alternatively, they might also evolve to directly infect large animals and kill humans.
I think the poison scenario may be worse because they can kill from a distance. Even if you sanitize entire cities with mirror antibiotics, poison from outside might still arrive due to the wind. Anyone with allergies knows the air is filled with spores and other biology.
Optimism
We can prepare for the risk before it happens. Not only can we make mirror antibiotics but “antimirroral” chemicals much stronger and less specific than antibiotics, which targets all mirror proteins etc. Well adapted mirror bacteria may survive far higher concentrations of “antimirrorics” than humans, but humans can pump out far higher concentrations of “antimirrorics” than the mirror bacteria, so we may win the fight if we prepare.
I also like your space lab idea, it allows us to empirically test how dangerous mirror life is without actually risking extinction. Not all risks can be empirically tested like this.
If there is an equilibrium, It will probably be a world where half the bacteria is of each chirality. If there are bacteria of both kinds which can eat the opposite kind, then the more numerous bacteria will always replicate more slowly.
Eukaryotes evolve much more slowly, and would likely all be wiped out.
I don’t know about microscopic eukaryotes, but yes the risk is that slow-evolving life (like humans) may be wiped out.
I agree the equilibrium could be close to half mirror bacteria, though in my mind a 1:10 ratio is “close to half.” The minority chirality has various advantages. It is less vulnerable to bacteriophages (and possibly other predators). It encounters the majority chirality more frequently than the majority chirality encounters it. This means the majority chirality has very little evolutionary pressure to adapt against it, while it has lots of evolutionary pressure to adapt to the majority chirality. The minority chirality will likely produce “antimirrorics” much more, until the two sides balance out (within an environment).
It probably won’t be exactly half, because normal chirality life does start off with way more species. It might evolve better “antimirrorics” or better resistance to them. The mirror bacteria will lack the adaptions to survive in many environments, though if it evolves quickly it might survive in enough major environments to become a severe risk.