[Ginden]

> How far are we away from gene editing that will allow humans to be born with working gills or wings?

Impossible due to physics limits. Human lungs have 57 square meters for extracting oxygen from fluid with 21% volume oxygen. 30°C air-saturated water have 0.5% of oxygen, so working gills for human would need surface area of 2394 square meters.

[rembicilious]

Gills work by continually “filtering” water as is flows through them. Lungs are filled and then emptied according to some pattern of breath. The difference in volume of fluid processed must be significant. Also, can’t gills have a higher surface area to volume ratio than lungs?