but also a unique genetic mutation - known as the 'sea nomad gene' - that also aids in their diving ability. They have extra large spleens. The tribe that evolved to stay underwater longer – BBC ...

Gwen is a young girl adopted by a nomad tribe in a desert post-apocalyptic world. When Gwen's friend is kidnapped, she and an old woman called Roseline embark on a trip to bring him back.

That’s largely the case today, but 7,000 years ago the vast desert was an altogether different place: a verdant world of trees and rivers and home to megafauna such as hippos and elephants.