The chimpanzee, also simply known as the chimp, is a medium-sized great ape species found in the forests and savannas of equatorial Africa. It has four confirmed subspecies and a fifth proposed one. When its close relative, the bonobo, was more commonly known as the pygmy chimpanzee, this species was often called the common chimpanzee or the robust chimpanzee. The chimpanzee and the bonobo are the only species in the genus Pan. Evidence from fossils and DNA sequencing shows that the two species are humans' closest living relatives.