Humans cannot develop gills naturally. Gills are respiratory organs that allow fish and other aquatic animals to extract oxygen from water. They are made up of thin, feathery projections that allow the exchange of gases between the water and the blood.
Humans do not have gills because we are land-dwelling mammals. Our respiratory system is designed to extract oxygen from the air, not from water. Our lungs are made up of alveoli, which are tiny air sacs that allow the exchange of gases between the air and the blood.
It is theoretically possible to develop artificial gills that would allow humans to breathe underwater. However, this would be a very complex and challenging undertaking. The artificial gills would need to be able to extract enough oxygen from the water to meet the needs of a human, and they would also need to be able to remove carbon dioxide from the blood.
There is some research being done on artificial gills, but it is still in the early stages. It is not clear if or when artificial gills that are practical and effective will be developed.
In the meantime, humans who want to explore the underwater world will need to rely on scuba gear or other breathing apparatus.
