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> Mirror life presents potential dangers. For example, a chiral-mirror version of cyanobacteria, which only needs achiral nutrients and light for photosynthesis

> Mirror life presents potential dangers. For example, a chiral-mirror version of cyanobacteria, which only needs achiral nutrients and light for photosynthesis, could take over Earth's ecosystem due to lack of natural enemies, disturbing the bottom of the food chain by producing mirror versions of the required sugars. Some bacteria can digest L-glucose; exceptions like this would give some rare lifeforms an unanticipated advantage Does this have "great filter" implications? If it confers such a huge advantage for a prokaryote to have the opposite chirality, then it must be very unlikely for prokaryotes to evolve from scratch, as if it wasn't then something would have evolved to take advantage of this. It means that "the evolution of a simple prokaryote" has definitely only happened once.

adrianN 8y ago
I find it pretty unlikely that nothing would evolve to eat the mirror bacteria. edit: it might take some time though. Wood was indigestible for a long time, giving us coal deposits.
- gilleain 8y ago
  Indeed, the premise is just wrong. It's not as if organisms cannot process biomolecules of the other handedness. There are enzymes called 'epimerases' and 'racemases' (https://en.wikipedia.org/wiki/Epimerase_and_racemase https://en.wikipedia.org/wiki/Epimerase_and_racemase) that convert stereocenters. While it's true that a mirror cell wall would be a barrier to being broken down, there's nothing that would fundamentally stop the evolution of a suitable degradation machinery for it.
- macspoofing 8y ago
  >I find it pretty unlikely that nothing would evolve to eat the mirror bacteria. It may be the case that there is no easy jump for existing prokaryotes to handle mirror proteins. However in the 'worst case', predation would simply re-emerge from the original prokaryote via speciation ... but it may take a long time.

adrianN 8y ago

I find it pretty unlikely that nothing would evolve to eat the mirror bacteria. edit: it might take some time though. Wood was indigestible for a long time, giving us coal deposits.

gilleain 8y ago
Indeed, the premise is just wrong. It's not as if organisms cannot process biomolecules of the other handedness. There are enzymes called 'epimerases' and 'racemases' (https://en.wikipedia.org/wiki/Epimerase_and_racemase https://en.wikipedia.org/wiki/Epimerase_and_racemase) that convert stereocenters. While it's true that a mirror cell wall would be a barrier to being broken down, there's nothing that would fundamentally stop the evolution of a suitable degradation machinery for it.
macspoofing 8y ago
>I find it pretty unlikely that nothing would evolve to eat the mirror bacteria. It may be the case that there is no easy jump for existing prokaryotes to handle mirror proteins. However in the 'worst case', predation would simply re-emerge from the original prokaryote via speciation ... but it may take a long time.