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Ren HY, Kum KY, Zhao YS, Yoo YJ, Jeong JS, Perinpanayagam H, Wang XY, Li GJ, Wang F, Fang H, Gu Y. Maxillary molar root and canal morphology of Neolithic and modern Chinese. Arch Oral Biol 2021; 131:105272. [PMID: 34600333 DOI: 10.1016/j.archoralbio.2021.105272] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2021] [Revised: 09/12/2021] [Accepted: 09/21/2021] [Indexed: 01/17/2023]
Abstract
OBJECTIVE This study aimed to characterize Neolithic human maxillary molars from archeological remains at the Jiaojia site, Shandong, China, and compare their ultrastructural features with sex and age-matched modern locals. DESIGN Maxillary first (n = 86) and second (n = 80) molars in 5000-year-old individuals (n = 50) from the Jiaojia site were scanned by cone-beam computed tomography (CBCT). Sex and age-matched control groups were assigned from oral surgical patients at Shandong University. Images were analyzed for crown size, root length, root morphology, canal inter-orifice distances, mesiobuccal canal morphology, and second mesiobuccal (MB2) canal prevalence and location. Neolithic and modern values were compared statistically using Chi-squared and Mann-Whitney test at p < .05. RESULTS Crown and root size were smaller, and canal inter-orifice distances were shorter in Neolithic maxillary molars than their modern counterparts. For mesiobuccal roots, Weine's Type I single canals were the most prevalent in Neolithic and modern first and second molars. MB2 canal prevalence were not significantly different (p > .05) in Neolithic (53.3%) or modern (60.5%) first molars, and Neolithic (11.3%) or modern (21.3%) second molars. But, MB2 prevalence was significantly higher for modern than ancient male first (p = .032) and second (p = .005) molars. Additionally, MB2 were located more mesially and closer to MB1 in Neolithic than modern molars. CONCLUSIONS Maxillary molar root and canal morphology of ancient 5000-year-old remains at the Jiaojia site resemble that of local patients. A trend towards larger tooth size, and more dispersed MB2 canals over this short evolutionary period warrants additional investigation.
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Affiliation(s)
- H Y Ren
- School and Hospital of Stomatology, Cheeloo College of Medicine, Shandong University & Shandong Key Laboratory of Oral Tissue Regeneration & Shandong Engineering Laboratory for Dental Materials and Oral Tissue Regeneration, Shandong Province, PR China
| | - K Y Kum
- Department of Conservative Dentistry, Dental Research Institute, National Dental Care Center for Persons with Special Needs, Seoul National University Dental Hospital, Seoul National University School of Dentistry, Seoul, Republic of Korea
| | - Y S Zhao
- Institute of Cultural and Heritage, Shandong University, Qingdao, PR China
| | - Y J Yoo
- Department of Conservative Dentistry, Dental Research Institute, National Dental Care Center for Persons with Special Needs, Seoul National University Dental Hospital, Seoul National University School of Dentistry, Seoul, Republic of Korea
| | - J S Jeong
- School of Nursing and Rehabilitation, Cheeloo College of Medicine, Shandong University, Shandong Province, PR China
| | - Hiran Perinpanayagam
- Division of Restorative Dentistry, Schulich School of Medicine & Dentistry, University of Western Ontario, London, Canada
| | - X Y Wang
- Department of Endodontics, School and Hospital of Stomatology, Cheeloo College of Medicine, Shandong University & Shandong Key Laboratory of Oral Tissue Regeneration & Shandong Engineering Laboratory for Dental Materials and Oral Tissue Regeneration, Shandong Province, PR China
| | - G J Li
- Department of Radiology, School and Hospital of Stomatology, Cheeloo College of Medicine, Shandong University & Shandong Key Laboratory of Oral Tissue Regeneration & Shandong Engineering Laboratory for Dental Materials and Oral Tissue Regeneration, Shandong Province, PR China
| | - F Wang
- Department of Radiology, School and Hospital of Stomatology, Cheeloo College of Medicine, Shandong University & Shandong Key Laboratory of Oral Tissue Regeneration & Shandong Engineering Laboratory for Dental Materials and Oral Tissue Regeneration, Shandong Province, PR China
| | - H Fang
- School of History and Culture, Shandong University, Jinan, PR China
| | - Y Gu
- Department of Endodontics, School and Hospital of Stomatology, Cheeloo College of Medicine, Shandong University & Shandong Key Laboratory of Oral Tissue Regeneration & Shandong Engineering Laboratory for Dental Materials and Oral Tissue Regeneration, Shandong Province, PR China.
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Ben-Dor M, Sirtoli R, Barkai R. The evolution of the human trophic level during the Pleistocene. AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY 2021; 175 Suppl 72:27-56. [PMID: 33675083 DOI: 10.1002/ajpa.24247] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Revised: 12/07/2020] [Accepted: 01/19/2021] [Indexed: 02/06/2023]
Abstract
The human trophic level (HTL) during the Pleistocene and its degree of variability serve, explicitly or tacitly, as the basis of many explanations for human evolution, behavior, and culture. Previous attempts to reconstruct the HTL have relied heavily on an analogy with recent hunter-gatherer groups' diets. In addition to technological differences, recent findings of substantial ecological differences between the Pleistocene and the Anthropocene cast doubt regarding that analogy's validity. Surprisingly little systematic evolution-guided evidence served to reconstruct HTL. Here, we reconstruct the HTL during the Pleistocene by reviewing evidence for the impact of the HTL on the biological, ecological, and behavioral systems derived from various existing studies. We adapt a paleobiological and paleoecological approach, including evidence from human physiology and genetics, archaeology, paleontology, and zoology, and identified 25 sources of evidence in total. The evidence shows that the trophic level of the Homo lineage that most probably led to modern humans evolved from a low base to a high, carnivorous position during the Pleistocene, beginning with Homo habilis and peaking in Homo erectus. A reversal of that trend appears in the Upper Paleolithic, strengthening in the Mesolithic/Epipaleolithic and Neolithic, and culminating with the advent of agriculture. We conclude that it is possible to reach a credible reconstruction of the HTL without relying on a simple analogy with recent hunter-gatherers' diets. The memory of an adaptation to a trophic level that is embedded in modern humans' biology in the form of genetics, metabolism, and morphology is a fruitful line of investigation of past HTLs, whose potential we have only started to explore.
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Affiliation(s)
- Miki Ben-Dor
- Department of Archaeology, Tel Aviv University, Tel Aviv, Israel
| | | | - Ran Barkai
- Department of Archaeology, Tel Aviv University, Tel Aviv, Israel
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Ungar PS. Dental evidence for the diets of Plio-Pleistocene hominins. AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY 2012; 146 Suppl 53:47-62. [PMID: 22101687 DOI: 10.1002/ajpa.21610] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Diet is fundamental to the interaction between an organism and its environment, and is therefore an important key to understanding ecology and evolution. It should come as no surprise then that paleoanthropologists have put a great deal of effort into reconstructing the diets of Plio-Pleistocene hominins. Most of this effort has focused on teeth; these durable parts of the digestive system are usually the most commonly preserved elements in vertebrate fossil assemblages. In this article, I review much of this work. Tooth size, occlusal morphology, enamel thickness, and microstructure provide evidence for the physical properties of the foods to which a species was adapted. Dental microwear can offer insights into the properties of foods that an individual ate on a day-to-day basis. Taken together, these lines of evidence can offer important insights into early hominin food choices and adaptations. New methods of analysis and theoretical perspectives are improving our understanding of the diets of Australopithecus, Paranthropus, and early Homo, and promise further progress long into the future.
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Affiliation(s)
- Peter S Ungar
- Department of Anthropology, University of Arkansas, Fayetteville, AR 72701, USA.
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Thompson CL, Donley EM, Stimpson CD, Horne WI, Vinyard CJ. The influence of experimental manipulations on chewing speed during in vivo laboratory research in tufted capuchins (Cebus apella). AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY 2011; 145:402-14. [PMID: 21469081 DOI: 10.1002/ajpa.21514] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/20/2010] [Accepted: 01/30/2011] [Indexed: 11/09/2022]
Abstract
Even though in vivo studies of mastication in living primates are often used to test functional and adaptive hypotheses explaining primate masticatory behavior, we currently have little data addressing how experimental procedures performed in the laboratory influence mastication. The obvious logistical issue in assessing how animal manipulation impacts feeding physiology reflects the difficulty in quantifying mechanical parameters without handling the animal. In this study, we measured chewing cycle duration as a mechanical variable that can be collected remotely to: 1) assess how experimental manipulations affect chewing speed in Cebus apella, 2) compare captive chewing cycle durations to that of wild conspecifics, and 3) document sources of variation (beyond experimental manipulation) impacting captive chewing cycle durations. We find that experimental manipulations do increase chewing cycle durations in C. apella by as much as 152 milliseconds (ms) on average. These slower chewing speeds are mainly an effect of anesthesia (and/or restraint), rather than electrode implantation or more invasive surgical procedures. Comparison of captive and wild C. apella suggest there is no novel effect of captivity on chewing speed, although this cannot unequivocally demonstrate that masticatory mechanics are similar in captive and wild individuals. Furthermore, we document significant differences in cycle durations due to inter-individual variation and food type, although duration did not always significantly correlate with mechanical properties of foods. We advocate that the significant reduction in chewing speed be considered as an appropriate qualification when applying the results of laboratory-based feeding studies to adaptive explanations of primate feeding behaviors.
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Affiliation(s)
- C L Thompson
- Department of Anthropology, Kent State University, OH 44242, USA.
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