How the ghost shark lost its stomach

Lack of digestive organ in fish and other animals linked to genes

LOOK MA, NO STOMACH  A ghost shark  manages just fine, thank you, without the highly acidic digestive zone known as a stomach. And now scientists have a better understanding, from a genetic perspective, why the fish and other animals lack the organ.

Kelvin Aitken/VWPics/Associated Press

 

Animals from lungfish and ghost sharks to platypuses have lost their acid-making stomachs over evolutionary time, and researchers have now traced the genetic changes behind these stomach upsets.