JUSTIN A. LEDOGAR, PhD
I am a biological anthropologist who studies the functional anatomy and evolution of the craniofacial complex and teeth in primates. My primary research interests focus on the feeding biomechanics and dietary adaptations of fossil hominins and extant primate species, including modern humans. I apply a range of methods in addressing the questions that interest me, including finite element analysis (FEA), geometric morphometrics, and mechanical testing of primate foods in the wild. I also collaborate with students and other researchers on projects that apply biomechanical modeling techniques to the study of form and function in non-primate animals (e.g., marsupials).
I am currently an Assistant Professor in the Department of Health Sciences at East Tennessee State University. Click here for my CV (updated 24-July-2022). |
RESEARCHCraniofacial biomechanics in extant non-human primatesThis research seeks to understand the functional and ecological significance of biomechanical variation in living primate species. For example, is high bite force leverage always associated with “hard object” feeding? What is the influence of phylogeny on patterns of biomechanical variation? The answers to these questions are necessary if researchers hope to formulate reliable hypotheses of hominin facial evolution.
Primate dietary ecology and food mechanical properties
This component of my research, recently supported by grant funding from The Leakey Foundation, focuses on fieldwork at Brownsberg Nature Park in the Amazon basin of Suriname. Data on feeding ecology, food mechanical properties, and feeding behavior in sympatric pitheciines are being collected in order to address questions related to craniofacial evolution in this group.
Diet and the evolution of dietary adaptations in fossil homininsThis research employs finite element analysis (FEA) to examine feeding biomechanics and dietary adaptation in fossil hominins. A major component of this project seeks to better understand the dietary selective pressures that drove australopith cranial diversity by testing various functional hypotheses about bite force production and craniofacial strength. We are currently analyzing feeding biomechanics in early Homo and aim to provide new mechanical data useful in reconstructing diet in the earliest members of the human genus.
Biomechanical consequences of facial reduction in modern humansThe evolution of the modern human craniofacial complex is characterized by a reduction in the size of the feeding system, including reductions in the size of the facial skeleton and teeth. The conventional view associates these changes with a shift toward eating foods that were less mechanically challenging to consume and/or foods that were processed using tools. This project examines modern human craniofacial biomechanics and functional consequences of evolutionary reductions in the craniofacial skeleton. Data on strain magnitude and orientation are also being applied to questions relevant to craniofacial surgery and operative repair.
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Biomechanical model of Chiropotes satanas showing digitally dissected jaw adductor muscles and areas of muscle attachment.
Male white-faced saki (Pithecia pithecia) accessing the seeds of an unripe Chrysophyllum cuneifolium fruit (Brownsberg, June 2018).
The fossilized skull of Australopithecus sediba (MH1) and a finite element model of its cranium depicting strains during a simulated premolar bite.
The distribution of von Mises strain magnitude in two modern human (Homo sapiens) crania.
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PEER-REVIEWED PUBLICATIONS
2023. Sansalone G, Profico A, Wroe S, Allen K, Ledogar J, Ledogar S, Mitchell DR, Mondanaro A, Melchionna M, Castiglione S, Serio C, Raia P. Homo sapiens and Neanderthals share high cerebral cortex integration into adulthood. Nature Ecology & Evolution 7: 42–50. Download PDF.
2022. Ledogar JA, Senck S, Villmoare BA, Smith AL, Weber GW, Richmond BG, Dechow PC, Ross CF, Grosse IR, Wright BW, Wang Q, Byron C, Benazzi S, Carlson KJ, Carlson KB, Pryor McIntosh LC, van Casteren A, Strait DS. Mechanical compensation in the evolution of the early hominin feeding apparatus. Proceedings of the Royal Society B 289: 20220711. Download PDF.
2021. Cook RW, Vazzana A, Sorrentino R, Benazzi S, Smith AL, Strait DS, Ledogar JA*. The cranial biomechanics and feeding performance of Homo floresiensis. Interface Focus 11: 20200083. Follow link to open access article on Royal Society website.
(*Corresponding author)
2021. JM Martin, AB Leece, S Neubauer, SE Baker, CS Mongle, G Boschian, Schwartz GT, Smith AL, Ledogar JA, Strait DS, Herries AIR. Drimolen cranium DNH 155 documents microevolution in an early hominin species. Nature Ecology & Evolution 5: 38-45. Download PDF.
2021. van Heteren AH, Wroe S, Tsang LR, Mitchell DR, Ross P, Ledogar JA, Attard MRG, Sustaita D, Clausen P, Scofield RP, Sansalone G. New Zealand's extinct giant raptor (Hieraaetus moorei) killed like an eagle, ate like a condor. Proceedings of the Royal Society B 288: 20211913.
2020. Sansalone G, Allen K, Ledogar J, Ledogar S, Mitchell D, Profico A, Castiglione S, Melchionna M, Serio A, Raia P, Wroe S. Variation in the strength of allometry drives rates of evolution in primate brain shape. Proceedings of the Royal Society B 287: 20200807. Download PDF.
2020. Valenta K, Daegling DJ, Nevo O, Ledogar J, Sarkar D, Kalbitzer U, Bortolamiol S, Omeja P, Chapman CA, Ayasse M, Kay R, Williams B. Fruit selectivity in anthropoid primates: Size matters. International Journal of Primatology 41: 525–537. Download PDF.
2019. Neaux D, Wroe S, Ledogar JA, Ledogar SH, Sansalone G. Morphological integration affects the evolution of midline cranial base, lateral basicranium, and face across primates. American Journal of Physical Anthropology 170: 37-47. Download PDF.
2019. Tsang LR, Wilson LAB, Ledogar J, Wroe S, Attard M, Sansalone G. Raptor talon shape and biomechanical performance are controlled by relative prey size but not by allometry. Scientific Reports 9: 7076. Follow link to open access article on Scientific Reports website.
2018. Ledogar JA, Luk THY, Perry JMG, Neaux D, Wroe S. Biting mechanics and niche separation in a specialized clade of primate seed predators. PLoS ONE 13(1): e0190689. Follow link to open access article on PLoS website.
2018. Bicknell RDC, Ledogar JA, Wroe S, Gutzler BC, Watson WH, Paterson JR. Computational biomechanical analyses demonstrate similar shell-crushing abilities in modern and ancient arthropods. Proceedings of the Royal Society B 285: 20181935. Download PDF.
2018. Mitchell DR, Sherratt E, Ledogar JA, Wroe SW. The biomechanics of foraging determines face length among kangaroos and their relatives. Proceedings of the Royal Society B-Biological Sciences 285(1881): 20180845. Download PDF.
2018. Wroe S, Parr WCH, Ledogar JA, Bourke J, Evans SP, Fiorenza L, Benazzi S, Hublin JJ, Stringer C, Kullmer O, Curry M, Rae T, Yokley T. Computer simulations show that Neanderthal facial morphology represents adaptation to cold and high energy demands, but not heavy biting. Proceedings of the Royal Society B-Biological Sciences 285(1876): 20180085. Download PDF.
2018. Neaux D, Sansalone G, Ledogar JA, Ledogar SH, Wroe S, Luk T. Basicranium and face: assessing the impact of morphological integration on primate evolution. Journal of Human Evolution 118:43-55. Download PDF.
2018. Mitchell DR, Sherratt E, Sansalone G, Ledogar JA, Flavel RJ, Wroe S. Feeding Biomechanics Influences Craniofacial Morphology at the Subspecies Scale among Australian Pademelons (Macropodidae: Thylogale). Journal of Mammalian Evolution 27, 199–209. Download PDF.
2017. Ledogar JA, Benazzi S, Smith AL, Weber GW, Carlson KB, Dechow PC, Grosse IR, Ross CF, Richmond BG, Wright BW, Wang Q, Byron C, Carlson KJ, de Ruiter DJ, Pryor LC, Strait DS. The biomechanics of bony facial “buttresses” in South African australopiths: an experimental study using finite element analysis. Anatomical Record 300:171-195. Download PDF.
2017. Neaux D, Bienvenu T, Guy F, Daver G, Sansalone G, Ledogar JA, Rae TC, Wroe S, Brunet M. Relationship between foramen magnum position and locomotion in extant and extinct hominoids. Journal of Human Evolution 113:1-9. Download PDF.
2016. Pryor McIntosh L, Strait DS, Ross CF, Wang Q, Smith AL, Ledogar JA, Opperman L, Dechow PC. Internal bone architecture in the zygoma of human and Pan. Anatomical Record 299:1704-1717. Download PDF.
2016. Prado FB, Freire AR, Rossi AC, Ledogar JA, Smith AL, Dechow PC, Strait DS, Voigt T, Ross CF. Review of in vivo bone strain studies and finite element models of the zygomatic complex in humans and non-human primates: Implications for clinical research and practice. Anatomical Record 299:1753-1778. Download PDF.
2016. Ledogar JA, Dechow PC, Wang Q, Gharpure PH, Gordon AD, Baab KL, Smith AL, Weber GW, Grosse IR, Ross CF, Richmond BG, Wright BW, Byron C, Wroe S, Strait DS. Human feeding biomechanics: performance, variation, and functional constraints. PeerJ 4: e2242. Follow link to open access article on PeerJ website.
2016. Ledogar JA, Smith AL, Benazzi S, Weber GW, Spencer MA, Carlson KB, McNulty KP, Dechow PC, Grosse IR, Ross CF, Richmond BG, Wright BW, Wang Q, Byron C, Slice DE, Carlson KJ, de Ruiter DJ, Berger LR, Tamvada K, Pryor LC, Berthaume MA, Strait DS. Mechanical evidence that Australopithecus sediba was limited in its ability to eat hard foods. Nature Communications 7:10596. Follow link to open access article on Nature website.
2015. Smith AL, Benazzi S, Ledogar JA, Tamvada K, Pryor Smith LC, Weber GW, Spencer MA, Dechow PC, Grosse IR, Ross CF, Richmond BG, Wright BW, Wang Q, Byron C, Slice DE, Strait DS. Biomechanical implications of intraspecific shape variation in chimpanzee crania: moving towards an integration of geometric morphometrics and finite element analysis. Anatomical Record 298:122-144. Download PDF.
2015. Smith AL, Benazzi S, Ledogar JA, Tamvada K, Pryor Smith LC, Weber GW, Spencer MA, Lucas PW, Michael S, Shekeban A, Al-Fadhalah K, Almusallam AS, Dechow PC, Grosse IR, Ross CF, Madden RH, Richmond BG, Wright BW, Wang Q, Byron C, Slice DE, Wood S, Dzialo C, Berthaume MA, van Castern A, Strait DS. The feeding biomechanics and dietary ecology of Paranthropus boisei. Anatomical Record 298:145-167. Download PDF.
2014. Winchester JM, Boyer DM, St. Clair EM, Gosselin-Ildari AD, Cooke SE, Ledogar JA. Dental topography of platyrrhines and prosimians: convergence and contrasts. American Journal of Physical Anthropology 153:29-44. Download PDF.
2013. Strait DS, Constantino P, Lucas PW, Chalk J, Richmond BG, Spencer MA, Schrein C, Dechow PC, Ross CF, Grosse IR, Wright BW, Wood BA, Weber GW, Wang Q, Byron C, Slice D, Smith AL, Smith LC, Wood S, Berthaume M, Benazzi S, Dzialo C, Tamvada K, Ledogar JA. Diet and dietary adaptations in early hominins: the hard food perspective. American Journal of Physical Anthropology 151:339-355. Download PDF.
2013. Ledogar JA, Winchester JM, St. Clair EM, Boyer DM. Diet and dental topography in pitheciine seed predators. American Journal of Physical Anthropology 150:107-121. Download PDF.
2011. Kamilar JM, Ledogar JA. Species co-occurrence patterns and dietary resource competition in primates. American Journal of Physical Anthropology 144:131-139. Download PDF.
2022. Ledogar JA, Senck S, Villmoare BA, Smith AL, Weber GW, Richmond BG, Dechow PC, Ross CF, Grosse IR, Wright BW, Wang Q, Byron C, Benazzi S, Carlson KJ, Carlson KB, Pryor McIntosh LC, van Casteren A, Strait DS. Mechanical compensation in the evolution of the early hominin feeding apparatus. Proceedings of the Royal Society B 289: 20220711. Download PDF.
2021. Cook RW, Vazzana A, Sorrentino R, Benazzi S, Smith AL, Strait DS, Ledogar JA*. The cranial biomechanics and feeding performance of Homo floresiensis. Interface Focus 11: 20200083. Follow link to open access article on Royal Society website.
(*Corresponding author)
2021. JM Martin, AB Leece, S Neubauer, SE Baker, CS Mongle, G Boschian, Schwartz GT, Smith AL, Ledogar JA, Strait DS, Herries AIR. Drimolen cranium DNH 155 documents microevolution in an early hominin species. Nature Ecology & Evolution 5: 38-45. Download PDF.
2021. van Heteren AH, Wroe S, Tsang LR, Mitchell DR, Ross P, Ledogar JA, Attard MRG, Sustaita D, Clausen P, Scofield RP, Sansalone G. New Zealand's extinct giant raptor (Hieraaetus moorei) killed like an eagle, ate like a condor. Proceedings of the Royal Society B 288: 20211913.
2020. Sansalone G, Allen K, Ledogar J, Ledogar S, Mitchell D, Profico A, Castiglione S, Melchionna M, Serio A, Raia P, Wroe S. Variation in the strength of allometry drives rates of evolution in primate brain shape. Proceedings of the Royal Society B 287: 20200807. Download PDF.
2020. Valenta K, Daegling DJ, Nevo O, Ledogar J, Sarkar D, Kalbitzer U, Bortolamiol S, Omeja P, Chapman CA, Ayasse M, Kay R, Williams B. Fruit selectivity in anthropoid primates: Size matters. International Journal of Primatology 41: 525–537. Download PDF.
2019. Neaux D, Wroe S, Ledogar JA, Ledogar SH, Sansalone G. Morphological integration affects the evolution of midline cranial base, lateral basicranium, and face across primates. American Journal of Physical Anthropology 170: 37-47. Download PDF.
2019. Tsang LR, Wilson LAB, Ledogar J, Wroe S, Attard M, Sansalone G. Raptor talon shape and biomechanical performance are controlled by relative prey size but not by allometry. Scientific Reports 9: 7076. Follow link to open access article on Scientific Reports website.
2018. Ledogar JA, Luk THY, Perry JMG, Neaux D, Wroe S. Biting mechanics and niche separation in a specialized clade of primate seed predators. PLoS ONE 13(1): e0190689. Follow link to open access article on PLoS website.
2018. Bicknell RDC, Ledogar JA, Wroe S, Gutzler BC, Watson WH, Paterson JR. Computational biomechanical analyses demonstrate similar shell-crushing abilities in modern and ancient arthropods. Proceedings of the Royal Society B 285: 20181935. Download PDF.
2018. Mitchell DR, Sherratt E, Ledogar JA, Wroe SW. The biomechanics of foraging determines face length among kangaroos and their relatives. Proceedings of the Royal Society B-Biological Sciences 285(1881): 20180845. Download PDF.
2018. Wroe S, Parr WCH, Ledogar JA, Bourke J, Evans SP, Fiorenza L, Benazzi S, Hublin JJ, Stringer C, Kullmer O, Curry M, Rae T, Yokley T. Computer simulations show that Neanderthal facial morphology represents adaptation to cold and high energy demands, but not heavy biting. Proceedings of the Royal Society B-Biological Sciences 285(1876): 20180085. Download PDF.
2018. Neaux D, Sansalone G, Ledogar JA, Ledogar SH, Wroe S, Luk T. Basicranium and face: assessing the impact of morphological integration on primate evolution. Journal of Human Evolution 118:43-55. Download PDF.
2018. Mitchell DR, Sherratt E, Sansalone G, Ledogar JA, Flavel RJ, Wroe S. Feeding Biomechanics Influences Craniofacial Morphology at the Subspecies Scale among Australian Pademelons (Macropodidae: Thylogale). Journal of Mammalian Evolution 27, 199–209. Download PDF.
2017. Ledogar JA, Benazzi S, Smith AL, Weber GW, Carlson KB, Dechow PC, Grosse IR, Ross CF, Richmond BG, Wright BW, Wang Q, Byron C, Carlson KJ, de Ruiter DJ, Pryor LC, Strait DS. The biomechanics of bony facial “buttresses” in South African australopiths: an experimental study using finite element analysis. Anatomical Record 300:171-195. Download PDF.
2017. Neaux D, Bienvenu T, Guy F, Daver G, Sansalone G, Ledogar JA, Rae TC, Wroe S, Brunet M. Relationship between foramen magnum position and locomotion in extant and extinct hominoids. Journal of Human Evolution 113:1-9. Download PDF.
2016. Pryor McIntosh L, Strait DS, Ross CF, Wang Q, Smith AL, Ledogar JA, Opperman L, Dechow PC. Internal bone architecture in the zygoma of human and Pan. Anatomical Record 299:1704-1717. Download PDF.
2016. Prado FB, Freire AR, Rossi AC, Ledogar JA, Smith AL, Dechow PC, Strait DS, Voigt T, Ross CF. Review of in vivo bone strain studies and finite element models of the zygomatic complex in humans and non-human primates: Implications for clinical research and practice. Anatomical Record 299:1753-1778. Download PDF.
2016. Ledogar JA, Dechow PC, Wang Q, Gharpure PH, Gordon AD, Baab KL, Smith AL, Weber GW, Grosse IR, Ross CF, Richmond BG, Wright BW, Byron C, Wroe S, Strait DS. Human feeding biomechanics: performance, variation, and functional constraints. PeerJ 4: e2242. Follow link to open access article on PeerJ website.
2016. Ledogar JA, Smith AL, Benazzi S, Weber GW, Spencer MA, Carlson KB, McNulty KP, Dechow PC, Grosse IR, Ross CF, Richmond BG, Wright BW, Wang Q, Byron C, Slice DE, Carlson KJ, de Ruiter DJ, Berger LR, Tamvada K, Pryor LC, Berthaume MA, Strait DS. Mechanical evidence that Australopithecus sediba was limited in its ability to eat hard foods. Nature Communications 7:10596. Follow link to open access article on Nature website.
2015. Smith AL, Benazzi S, Ledogar JA, Tamvada K, Pryor Smith LC, Weber GW, Spencer MA, Dechow PC, Grosse IR, Ross CF, Richmond BG, Wright BW, Wang Q, Byron C, Slice DE, Strait DS. Biomechanical implications of intraspecific shape variation in chimpanzee crania: moving towards an integration of geometric morphometrics and finite element analysis. Anatomical Record 298:122-144. Download PDF.
2015. Smith AL, Benazzi S, Ledogar JA, Tamvada K, Pryor Smith LC, Weber GW, Spencer MA, Lucas PW, Michael S, Shekeban A, Al-Fadhalah K, Almusallam AS, Dechow PC, Grosse IR, Ross CF, Madden RH, Richmond BG, Wright BW, Wang Q, Byron C, Slice DE, Wood S, Dzialo C, Berthaume MA, van Castern A, Strait DS. The feeding biomechanics and dietary ecology of Paranthropus boisei. Anatomical Record 298:145-167. Download PDF.
2014. Winchester JM, Boyer DM, St. Clair EM, Gosselin-Ildari AD, Cooke SE, Ledogar JA. Dental topography of platyrrhines and prosimians: convergence and contrasts. American Journal of Physical Anthropology 153:29-44. Download PDF.
2013. Strait DS, Constantino P, Lucas PW, Chalk J, Richmond BG, Spencer MA, Schrein C, Dechow PC, Ross CF, Grosse IR, Wright BW, Wood BA, Weber GW, Wang Q, Byron C, Slice D, Smith AL, Smith LC, Wood S, Berthaume M, Benazzi S, Dzialo C, Tamvada K, Ledogar JA. Diet and dietary adaptations in early hominins: the hard food perspective. American Journal of Physical Anthropology 151:339-355. Download PDF.
2013. Ledogar JA, Winchester JM, St. Clair EM, Boyer DM. Diet and dental topography in pitheciine seed predators. American Journal of Physical Anthropology 150:107-121. Download PDF.
2011. Kamilar JM, Ledogar JA. Species co-occurrence patterns and dietary resource competition in primates. American Journal of Physical Anthropology 144:131-139. Download PDF.
POPULAR MEDIA COVERAGE
Coverage for the 2021 Interface Focus article on Homo floresiensis feeding mechanics:
Coverage for the 2021 Nature Ecology & Evolution article on the new Paranthropus robustus skull from Drimolen:
Coverage for the 2016 PeerJ article on human feeding biomechanics:
Coverage for the 2016 Nature Communications article on feeding biomechanics in Australopithecus sediba:
- Link to "The hobbit's bite gets a stress test" (Phys.org)
- Link to "New Study Examines Chewing Biomechanics of Homo floresiensis" (Sci-News)
Coverage for the 2021 Nature Ecology & Evolution article on the new Paranthropus robustus skull from Drimolen:
- Link to "How a human cousin adapted to a changing climate" (NY Times)
- Link to "Two-million-year-old skull of human 'cousin' unearthed" (BBC)
Coverage for the 2016 PeerJ article on human feeding biomechanics:
- Link to "Powerful, efficient human bite is an accident of evolution: Study" (United Press International)
- Link to "Humans pack an efficient bite, but at a cost" (Phys.org)
Coverage for the 2016 Nature Communications article on feeding biomechanics in Australopithecus sediba:
- Link to "Biting off more than it can chew: human ancestor struggled to eat hard foods" (The Guardian)
- Link to "Early human ancestor jaws were not built for hard-food diet, say Australian scientists" (The Independent)
- Link to "Early human ancestor didn't have a nutcracker jaw" (United Press International)
- Link to "Early human ancestor didn't have the jaws of a nutcracker, study finds" (Phys.org)
- Link to "Scientists Simulate Biting Ability of Australopithecus sediba" (Archaeology.org)
- Link to "Study: Australopithecus sediba Didn’t Eat Hard Foods" (Sci-News)