Chimps: Human's Closest Relatives

Chimpanzee sometimes also called as chimp is actually name of the two living species of ape kept in the genus Pan. Congo River forms the boundary between the habitats of these two species. These two species are the Common Chimpanzee and the Bonobo. Chimpanzees are placed along with gorillas, humans and orangutans in the family Hominidae. They evolved about 6 million years ago and are the closest relatives of humans. The two Pan species are believed to have split about 1 million years ago.

A lot of fossil records about humans are available but the fossil record of chimpanzee was not known before 2005. The existing populations of these animals in the West and Central Africa do not overlap the Human fossil sites namely east Africa. The fossils of these animals have been recovered from Kenya. It indicates that both humans and chimpanzee populations dwelled in the Rift Valley of East Africa during the Pleistocene. The male attains a height of 1.7 m and may weigh up to kg while female is somewhat smaller. The arms are long and are about one and a half times longer than the body height. The arms are even longer than the legs. The Bonobo is somewhat shorter and thinner than the common chimpanzee but has longer limbs. Both species use their long arms for climbing on trees. When on ground they use their knuckles to walk and the locomotion is known as knuckle walking.

Chimpanzees are better adapted for walking on ground as compared to the orangutans as their soles are broad and toes are shorter. Both the species can walk upright on their two legs while holding any object in the arms. Bonobo walks more perfectly on the two legs as compared to the chimp. The fur coat is dark in colour, face, fingers, palms of the hands, and soles of the feet are hairless and chimps lack tail. The exposed part of the skin especially of the face, hands and feet may be pink to dark in colouration. Jaws are somewhat protruding. The brain is about half the size of human brain. The testicles are somewhat as compared to the body size. This can be attributed to the polyandrous nature of their mating behaviour. They attain sexual maturity at the age of 8-10 years of age with an average lifespan of 40 years. Some chimps have been found to live for about 60 years when kept in captivity.

Both the species have slight variations in their external appearance but their social and sexual behaviours have marked differences. The common chimp has an omnivorous diet with a troop hunting which is led by alpha male showing highly complex social relationship. On the other hand bonobo are frugivorous in their diet with egalitarian, nonviolent, matriarchal, sexually receptive behaviour. Chimps live in multi-male and multi-female groups known as communities. There is a dominant male known as alpha male. This male controls all the activities of the group. Female groups also have hierarchy controlled by a female. The females prefer an alpha male for mating. They are known to make tools in order to gather food and social displays. They are also capable of showing sophisticated hunting strategies requiring cooperation, influence and rank; they are status conscious, manipulative and capable of deception; they can learn to use symbols and understand aspects of human language including some relational syntax, concepts of number and numerical sequence. They communicate through vocalizations, hand gestures, and facial expressions. They have sharp memories. Chimps, gorillas and orangutans show laughter like displays in response to physical contact, such as wrestling, play chasing, or tickling. The males are highly aggressive and can even kill other chimps.