From Sam Edge, Ringwood, Hampshire, UK
If we exclude the panspermia hypothesis, then life on Earth, with key biomolecules utilising only one of two possible mirror-image – or chiral – forms, arose from random “experiments” in which prebiotic molecules became self-replicating and able to adapt (1 March, p 34).
It seems unlikely that only a single instance survived to go on to create all life. If there were multiple instances, then, statistically, some must have had the opposite chirality.
That none of these endured suggests that something in that chirality made them less fit to spread, either due to biochemistry or because the chirality of observed life outperformed them. This implies that if we did manage to create “mirror life”, it too would be less fit and would die out again without artificial support. In the long term, most life on Earth would be unaffected.
