Gastric acid in vertebrates.
Gastric secretion of hydrochloric acid appears to be unique to vertebrates and is almost ubiquitous in all fishes, amphibians, reptiles, birds and mammals. Comparative anatomy and physiology suggest that gastric acid has evolved approximately 350 million years ago. The similarity of the acid-secreting mechanism across all classes of vertebrates implies a major advantage for selection, but the evidence regarding its precise purpose remains inconclusive.
Koelz
H R
HR
Dept. of Medicine, Stadtspital Triemli, Zurich, Switzerland.
D000818:Animals; D005075:Biological Evolution; D004063:Digestion / Q000502:physiology; D005399:Fishes; D005744:Gastric Acid / Q000378:metabolism*; D005753:Gastric Mucosa / Q000378:metabolism; D006801:Humans; D013270:Stomach / Q000033:anatomy & histology; D014714:Vertebrates / Q000502:physiology*