Papio is a genus; all baboons belong to the genus Papio. Previously, Gelada, Mandrill and Drill were also grouped into the same genus but they now have their own separate genera. Gelada belongs to the genus Theropithecus while Mandrill and Drill belong to the genus Mandrillus. Gelada, Mandrill, and Drill are still colloquially referred to as baboons.
Currently the genus Papio has 5 recognized members. There are disagreements among scientists whether Hamadryas baboons are a separate species while the other four are subspecies or they all represent 5 different species of the same genus. You will see that Hamadryas baboons are listed as either Papio hamadryas or Papio hamadryas hamadryas.
Based on the biological species concept, I consider all 5 members of the genus Papio to be a subspecies of Papio hamadryas because they can reproduce and produce virile offspring hybrids. The closer the range of two baboon species, the higher the frequency of interbreeding is. This zone is sometimes call the hybrid zone. According to the ecological species concept, however, I consider all 5 members of the genus Papio to be 5 different species. So, depending on what your species concept is, there are different ways to classify them. How would you classify them and why?
The 5 Papio species are:
- Chacma Baboon, Papio ursinus (found in southern Africa).
- Guinea Baboon, Papio papio (found in the far western Africa).
- Hamadryas Baboon, Papio hamadryas (found in the Horn of Africa and south-western Arabia).
- Olive Baboon, Papio anubis (found in the north-central African savanna).
- Yellow Baboon, Papio cynocephalus (found in south-central and eastern Africa).