D
Dental Formula
the quantity of each type of tooth (incisor, canine, premolar, and molar) in each quadrant of the mouth, counting from the front. The human dental formula is 2.1.2.3. The Old World monkeys and apes also share this dental formula.
Digits
fingers and toes. See pentadactylism.
Displays
visual messages, or body language, used by primates and other animals primarily to communicate anger, fear, and other basic emotions. Displays are a strong indication of an animal's emotional state.
Diurnal
being awake and active during the daylight hours but sleeping during the night time. See nocturnal and crespecular.
DNA
a large organic molecule that stores the genetic code for the synthesis of proteins. DNA is composed of sugars, phosphates and bases arranged in a double helix shaped molecular structure. Segments of DNA in chromosomes correspond to specific genes.
Dominance hierarchies
Primate societies usually have hierarchies-each adult member has a rank. Both males and females have dominance hierarchies. They vary in stability and linearity.