Geographic Variation in Gorilla Limb Bones

Rebecca Jabbour, Tessa L. Pearman

Research output: Contribution to journalArticlepeer-review


<p> <p id="x-x-x-x-x-x-x-abspara0010"> Gorilla systematics has received increased attention over recent decades from primatologists, conservationists, and paleontologists. Studies of geographic variation in DNA, skulls, and teeth have led to new taxonomic proposals, such as recognition of two gorilla species, <em> <a href="" title="Learn more about Western gorilla"> Gorilla gorilla </a> </em> (western gorilla) and <em> Gorilla beringei </em> (eastern gorilla). <a href="" title="Learn more about Postcrania"> Postcranial </a> differences between mountain gorillas ( <em> G. beringei beringei </em> ) and western lowland gorillas ( <em> G. g. gorilla </em> ) have a long history of study, but differences between the limb bones of the eastern and western species have not yet been examined with an emphasis on geographic variation within each species. In addition, proposals for recognition of the Cross River gorilla as <em> Gorilla gorilla diehli </em> and gorillas from Tshiaberimu and Kahuzi as <em> G. b. rex-pymaeorum </em> have not been evaluated in the context of geographic variation in the forelimb and hindlimb skeletons. <p id="x-x-x-x-x-x-x-abspara0015"> Forty-three linear measurements were collected from limb bones of 266 adult gorillas representing populations of <em> G. b. beringei </em> , <em> Gorilla beringei graueri </em> , <em> G. g. gorilla </em> , and <em> G. g. diehli </em> in order to investigate geographic diversity. Skeletal elements included the <a href="" title="Learn more about Humerus"> humerus </a> , radius, third metacarpal, third proximal hand <a href="" title="Learn more about Phalange Bone"> phalanx </a> , femur, <a href="" title="Learn more about Tibia"> tibia </a> , calcaneus, first metatarsal, third metatarsal, and third proximal foot phalanx. Comparisons of means and principal components analyses clearly differentiate eastern and western gorillas, indicating that eastern gorillas have absolutely and relatively smaller hands and feet, among other differences. Gorilla subspecies and populations cluster consistently by species, although <em> G. g. diehli </em> may be similar to the eastern gorillas in having small hands and feet. The subspecies of <em> G. beringei </em> are distinguished less strongly and by different variables than the two gorilla species. Populations of <em> G. b. graueri </em> are variable, and Kahuzi and Tshiaberimu specimens do not cluster together. Results support the possible influence of higher-altitude Pleistocene refugia on patterns of geographic variation in gorillas. </p> </p></p>
Original languageAmerican English
JournalJournal of Human Evolution
StatePublished - Jun 16 2016


  • African ape
  • Taxonomy
  • Skeleton
  • Hand
  • Foot
  • Altitude


  • Biology
  • Evolution

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