The chimpanzee lives in groups that range in size from 15 to 150 members, although individuals travel and forage in much smaller groups during the day. It is larger and more robust than the bonobo, weighing 40–70 kg (88–154 lb) for males and 27–50 kg (60–110 lb) for females and standing 120 to 150 cm (3 ft 11 in to 4 ft 11 in). The chimpanzee is covered in coarse black hair, but has a bare face, fingers, toes, palms of the hands, and soles of the feet. Evidence from fossils and DNA sequencing shows that Pan is a sister taxon to the human lineage and is humans' closest living relative. The chimpanzee and the closely related bonobo are classified in the genus Pan. It has four confirmed subspecies and a fifth proposed subspecies. The chimpanzee ( Pan troglodytes), also known simply as chimp, is a species of great ape native to the forest and savannah of tropical Africa. Anthropopithecus troglodytes ( Sutton, 1883).Troglodytes troglodytes (Blumenbach, 1776).The cookie is set by the GDPR Cookie Consent plugin and is used to store whether or not user has consented to the use of cookies. The cookie is used to store the user consent for the cookies in the category "Performance". This cookie is set by GDPR Cookie Consent plugin. The cookie is used to store the user consent for the cookies in the category "Other. The cookies is used to store the user consent for the cookies in the category "Necessary". The cookie is set by GDPR cookie consent to record the user consent for the cookies in the category "Functional". The cookie is used to store the user consent for the cookies in the category "Analytics". These cookies ensure basic functionalities and security features of the website, anonymously. Necessary cookies are absolutely essential for the website to function properly. The findings of the study also challenge the assumption that a chimp-like hand was the starting point of the chimpanzee-human LCA.
These results support the hypothesis that the long thumb to fingers ratio of the human hand was acquired convergently with other highly dexterous anthropoids. Their results show the more recent, convergent evolution of finger elongation in chimpanzees and orangutans and comparatively little change between humans, human ancestors and gorillas. The researchers measured the hand proportions of humans, living and fossil apes as well as fossils of human ancestors including Ardipithecus ramidus and Australopithecus sediba, to understand the step wise evolution of the hand. This is one of the most distinctive traits of humankind compared to apes and is often cited as one of the reasons for the success of the species however there are competing theories on how the human hand evolved over time. Human hands exhibit a long thumb in relation to the fingers. These findings indicate that the structure of the modern human hand is largely primitive in nature, rather than the result of selective pressures in the context of stone tool-making. Human hand proportions have changed little from those of the last common ancestor (LCA) of chimpanzees and humans.
The work is done by Stony Brook University’s Sergio Almecija, Jeroen Smaers and William Jungers. Two days ago, Nature published a paper “The evolution of human and ape hand proportions,”a study that discovers that human hands may be more primitive than chimp’s. A study about the evolution of the human shows there has been relatively little change in its proportions.