Human digestive system digestive system is subject to a wide range of disorders many of which can be congenital. Mouth diseases can also be caused by pathogenic bacteria, viruses, fungi and as a side effect of some medications. Mouth diseases include tongue diseases and salivary gland diseases. A common gum disease in the mouth is gingivitis which is caused by bacteria in plaque. The most common viral infection of the mouth is gingivostomatitis caused by herpes simplex. A common fungal infection is candidiasis commonly known as "thrush" which affects the mucous membranes of the mouth. There are a number of esophageal diseases such
Chimpanzee–human last common ancestor Chimpanzee–human last common ancestor The chimpanzee–human last common ancestor, or CHLCA, is the last common ancestor shared by the extant "Homo" (human) and "Pan" (chimpanzee) genera of Hominini. Due to complex hybrid speciation, it is not possible to give a precise estimate on the age of this ancestral individual. While "original divergence" between populations may have occurred as early as 13 million years ago (Miocene), hybridization may have been ongoing until as recently as 4 million years ago (Pliocene). Speciation from "Pan" to "Homo" appears to have been a long, drawn-out process. After the original divergences, there were, according to