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Comment by dash2 | Hacker News Reader

If mirror bacteria could spread and avoid the body's immune defences, why has it not already evolved?

This isn't something that could be caused by a mutation in a single nucleotide or a segment being deleted or inserted, the way normal mutations happen and get passed on. This would be an entirely different set of (mirrored) machinery composing (mirrored) structures from (mirrored) subunits.

Whatever caused life to begin in the first place would maybe be the right place to look to recreate this naturally. If life began again from step 0, but with the opposite chirality, it could then progress forward towards mirrored bacteria.

Because it's too much of a lift at once. To naturally get a mirror E-Coli you'd need a separate planet and billions of years and lots of luck.

It's a mostly-incompatible change to all the machinery all the way down.

I could see "semi-mirror" life evolving step-by-step. There's a few microbes that can eat L-Glucose already (although the enzymes involved seem to be meant for other compounds and just happen to work for it), they just aren't taking advantage of it yet.

That's a far cry from, say, developing reversed DNA and reversed DNA polymerase and all the other transformative and/or structural proteins of the cell.

It's not just about the food/excretions of the hypothetical cell, but about whether its structure and innards are things the rest of the ecology can detect/defend-against/consume.

because as it was never observed to date, it could be assumed it does not exists yet, as the the article makes it sounds like it's very artificial / constructed

I swear I read of pharma companies experimenting with this. The idea that because the molecules are so foreign, the body lacks enzymes to breakdown the product, so the drug gets a much longer half-life than would be typical.

The underlying property is called "chirality" and describes why a left glove and a right glove are meaningfully different from each other even though they have the same topology.

Many things can have chirality: big things like gloves, and small things like drugs. The concept is not alone a danger. The concept of a thing which could take our raw materials, disassemble them, and recompose them in a way that would deny us the use of those resources, that is the stuff of sci fi horror thriller.

It sounds like the first thing that should be done is to contact Hollywood to make a really terrifying movie.

In the sequel Russia will have bred a new generation of opposite-chirality humans and will be racing to colonize space first.

(The big in-joke will be that they all wear the same gloves)

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