The gorilla is the largest of the primates. The males average 5 ft 8 in (1,73 m). high and may exceed 6 ft (1,83 m), and the females are about a foot (30 cm) less.An adult gorilla male may weigh 400—450 lb (181—204 kg) but in a zoo he tends to get fat and may weigh 100 lb (45 kg) more.
The closest relatives of gorillas are chimpanzees and humans.
The adult gorilla male develops a silvery white back.
The gorilla also has a large sagittal crest (a bony crest on the top of the skull) to which the jaw muscles packed with connective tissue are attached. This gives a helmet-like effect to the head. The nostrils are broad and the ear is small, in contrast with that of the closely related chimpanzee. The chest is broad and the neck short and muscular. The hands and feet are broad and strong, the great toe being less widely separated from the other toes than in the rest of the apes.
Gorillas are divided into two species and either four or five subspecies.
A gorilla walks normally on all fours, with knuckles to the ground, in a semierect posture because the arms are longer than the legs. Adult gorillas seldom climb trees.
There are three very well-marked races. The western gorilla lives in lowland rain forest, from sea level to about 6000 ft, in the Congo (Brazzaville), Gabon, Equatorial Guinea, Cameroun, extreme southwest of Central African Republic, and in the extreme southeast of Nigeria. The eastern lowland gorilla is found in a similar habitat in the eastern Congo (Kinshasa), ascending the mountains in the Central African Lakes region to about 8 000 ft. There are no gorillas in the vast lowland forest area between the ranges of these two races, and it is somewhat of a mystery why this should be. Finally, the mountain gorilla is found between 9000 and 12000 ft in the Virunga Volcanoes and Mt Kahuzi. All eastern gorillas are blacker than western, with larger jaws and bigger teeth; mountain gorillas are distinguished, in addition, by their comparatively short arms, long silky hair, and strikingly manlike feet.
Human genes differ only 1.6 percent on average from their corresponding gorilla genes in their sequence.
