Orangutans (Pongo spp.) Fact Sheet: Taxonomy & History

Taxonomic debate

• Some researchers believe that the Pongo is too different morphologically and behaviorally from humans to include it in Hominidae, and prefer to use Pongidae.
• Most orangutan taxonomists now view Bornean and Sumatran orangutans as two distinct species, rather than merely subspecies of Pongo (Brandon-Jones et al. 2004)
  • Sumatran and Bornean orangutans show differences in genetic makeup, morphology, ecological adaptations (Groves 2001) (Steiper 2005)
  • A study by Nater et al. (2017) indicates there is a third species of orangutan, the Tapanuli orangutan, Pongo tapanuliensis
    • Genetically isolated from Sumatran and Bornean species
    • Morphologically distinct
• Bornean orangutans are now further divided into 3 distinct subspecies (Singleton et al. 2004)
  • See review in Goossens et al. (2009)
• However, some researchers consider the Borneo's and Sumatra's populations as subspecies of Pongo (Courtnay et al. 1998) (Muir et al. 2000)

**Note: Taxonomic changes in light of this study are being evaluated by taxonomic scientists. As of December 2017, the IUCN recognizes three species of orangutan: Pongo abelii, P. pygmaeus, and P. tapanuliensis.

Common names in various languages

• Orangutan, Orang hutan, Mawas, Mawih, Kihau

• Looking at distribution of fossil hominids over space and time, researchers Grehan & Schwartz (2009), analyzed physical characteristics of living and fossil hominoids and tested theories of their relatedness:
  • They conclude that orangutans and humans share a common ancestor that had "established a wide distribution by at least 13 million years ago"
  • They note that molecular evidence is often cited in support of an alternate concept - that humans and chimpanzees share a common ancestor
• In a critique of Grehan & Schwartz (2009) biologists Lehtonen et al. (2011) assert chimpanzees, not orangutans, should still be viewed as sharing a common ancestor with humans:
  • They compared compared extensive data sets of DNA studies and morphological traits for fossil and living taxa and conclude that chimpanzees are human's' nearest relatives
  • They acknowledge that there are many similarities between humans and orangutans in life history, physiology, behavior and culture
• Recent discovery in northern Thailand of 13 million year old fossil teeth, very similar to the orangutan (Chaimanee, et al.  2003)
• Orangutans were common throughout mainland and island Southeast Asia 2 million years ago (Delgado & Van Schaik 2000)
• Steiper (2005) states that Sumatra and Borneo orangutans diverged from one another 2.7-5 million years ago, but several other studies suggest younger dates for the divergence of these two species
  • Nater et al. (2017) suggest ~ 674 kya
• Pongo tapanuliensis is the oldest lineage in the genus Pongo (Nater et al. 2017)
  • Diverged from other two orangutan species approximately 3.38 mya (Nater et al. 2017, Figure 3B

Popular cultural references

• Documentary appearances
  
• The Orangutan King - 2004, BBC
• The fearless ruler of the orangutans in the Camp Leakey sanctuary and in the jungles of Borneo, a new arrival could cause a challenge for Kusasi's throne.
• Orangutan Diary - Season 1 2007, Season 2 2010, BBC
  
• Season 1 has 5 episodes, while season 2 has 10. Season 1 provides a uniqe insight into the Borneo Orangutan Survival Foundation. Season 2 takes place two years after the visit to the Borneo Orangutan Survival Foundation. The series works with the Foundation as they work to save this species on the verge of extinction.
  
• The Secret Life of Primates - 2009, BBC
• Primatologist Charlotte Uhlenbroek travels to Borneo to encounter the native orangutans who are fighting for survival.
• Facing Extinction - 2013, BBC
• Eighteen years ago Terry  Prachett had a life-changing experience in the jungles of Borneo, where he encountered orangutans in the wild for the first time. Now he is going back to find out what the future holds for these endangered species, and discover a new threat to their habitat that could push them to the brink of extinction.
• The Last Orangutan Eden - 2015, PBS
• This one hour episode from the 33rd season of Nature takes a look at wild orangutans of Northern Sumatra as humans study their culture and behavior.

Kingdom: Animalia

Phylum: Chordata

Class: Mammalia

Order: Primates

Superfamily: Anthropoidea

Family: Hominidae (synonym: Pongidae)

Genus: Pongo

Species: Pongo abelii (Sumatran orangutan)
Species: Pongo tapanuliensis (Tapanuli orangutan)
Species: Pongo pygmaeus (Bornean orangutan)

Subspecies:
Pongo pygmaeus pygmaeus
Pongo pygmaeus morio
Pongo pygmaeus wurmbii

Describer (Date): Linnaeus (1760) Simia pygmaeus

Source: Nater et al. (2017)

Brandon-Jones et al. (2004)
Courtney et al. (1998)
Delgado & van Schaik. (2000)
Fleagle, (1999)
Grehan & Schwartz (2009)
Lehtonen et al. (2011)
Muir et al., (1998)
Muir et al. (2000)
Singleton et al. (2004)
Steiper (2005)
Tuttle, (2001)
Warren et al., (2001)
Wilson & Reeder, (1993)
Xu & Arnason, (1996)