> Many fish living in underground caves have lost their eyes through evolution. some have, yes. but in order to get the antibiotic benefit we're looking for, y

> Many fish living in underground caves have lost their eyes through evolution. some have, yes. but in order to get the antibiotic benefit we're looking for, you'd need to have ALL fish having lost their eyes. That's a much higher bar. ( https://en.wikipedia.org/wiki/Blind_fish https://en.wikipedia.org/wiki/Blind_fish seems to be a reasonably comprhensive list ). We also need the antibiotics to be viable again in a reasonable timespan ( a decade or two?), in order to be useful -- not on the timescale that was involved in cavefish eye degeneration.