Physical Differences Between Paniscus And The Chimpanzee And Chimanzees

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Species is a complex term, and is not as simple as one might think. A biological species can be defined as members of populations that actually or potentially interbreed in nature and produce fertile offspring. The concept of biological species has nothing to do with the similarity of appearance, and is a useful concept to keep in mind when looking at the common chimpanzee (Pan troglodytes) and the pygmy chimpanzee or bonobo (Pan paniscus), which are considered to be the two living species of chimpanzees today. These two species are great apes belong to the genus Pan, and can only be found in the West and Central Africa. There is a range of evidence that supports the existence of two distinct species, including genetic, behavioural and physical. paniscus and P. troglodytes provides evidence supporting the existence of two distinct species. The P. paniscus are smaller and leaner than chimps with black faces and pink lips, while the P. troglodytes are stockier and taller with brown lips and their faces change colour with age. The P. paniscus also has longer head hair that parts slightly down the middle (Boesch, Hohmann, & Marchant, 2002). The skeletal dimensions of each species were compared and significant differences were found in the clavicles, scapulae, pelvises, and in the humerus/femur and femur head/length ratios (Zihlman & Cramer, 1978). These difference show that the P. paniscus and P. troglodytes are physical different, supporting the existence of two distinct species. The physical difference between the two species could be linked to the difference in the habitats of each species, the P. troglodytes spend a lot of their time in the trees, and the P. troglodytes sleeps in the trees, while the P. paniscus spend their time on the
What separates on species from another are reproductive isolating mechanism (RIMs). RIMs can pre-zygotic and post-zygotic meaning they act before fertilisation and after fertilisation. Pre-zygotic RIMs include temporal isolation, behavioural isolation, ecological isolation and mechanical isolation. Post-zygotic RIMs include gametic incompatibility, zygotic mortality, and hybrid sterility just to name a few. The P. paniscus and P. troglodytes show behavioural isolation. The P. paniscus and the P. troglodytes both have different behavioural traits that would separate the species and work as reproductive isolating mechanisms (Boesch, Hohmann, & Marchant, 2002). They also show ecological isolation because they are separated by the Congo River as well as the P. troglodytes spends most of its time in the trees, their habitats do not cross over. This is supported by the research looking at the mitochondria DNA of the P. paniscus populations separated by rivers (Eriksson, Hohmann, Boesch, & Vigilant,

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