1
|
Emken S, Witzel C, Kierdorf U, Frölich K, Kierdorf H. A labeling study of dentin formation rates during crown and root growth of porcine mandibular first molars. Anat Rec (Hoboken) 2024; 307:2103-2120. [PMID: 38051150 DOI: 10.1002/ar.25358] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2023] [Revised: 11/14/2023] [Accepted: 11/15/2023] [Indexed: 12/07/2023]
Abstract
We used fluorochrome labeling to study spatiotemporal variation of dentin apposition (DAR) and extension (DER) rates during crown and root formation of mandibular first molars from wild boar and domestic pigs. DAR was reconstructed along the course of dentinal tubules in four zones of the crown and in the upper root area. In all five zones, mean DAR increased during the first 30% to 40% of apposition, reaching highest values (22-23 μm/day) in the upper-lateral crown zone. Lowest values were recorded near the dentin-pulp interface (DPI). Typically, DARs in contemporaneously formed dentin areas were higher in more cuspally compared to more cervically/apically located zones. DER was high (>200 μm/day) in early postnatal crown dentin and then decreased markedly in cervical direction, with lowest values in the cervical crown zone. After this nadir, DER sharply increased in the upper 30% to 40% of the root extension, reaching values equaling (wild boar) or even surpassing (domestic pigs) those recorded in the upper lateral crown. After this peak, DER again decreased. While DAR did not differ markedly between wild boar and domestic pigs, the DER showed marked differences, both regarding maximum values (208.1 μm/day in wild boar, 272.2 μm/day in domestic pigs) and the timing of the root growth spurt, which occurred earlier in the domestic pigs. We consider the more rapid recruitment of secretory odontoblasts in domestic pigs (reflected by higher DER) a side effect of selection for rapid body growth during pig domestication.
Collapse
Affiliation(s)
- Simon Emken
- Department of Biology, University of Hildesheim, Hildesheim, Germany
| | - Carsten Witzel
- Department of Biology, University of Hildesheim, Hildesheim, Germany
| | - Uwe Kierdorf
- Department of Biology, University of Hildesheim, Hildesheim, Germany
| | - Kai Frölich
- Department of Biology, University of Hildesheim, Hildesheim, Germany
- Tierpark Arche Warder e.V., Warder, Germany
| | - Horst Kierdorf
- Department of Biology, University of Hildesheim, Hildesheim, Germany
| |
Collapse
|
2
|
Mahoney P, McFarlane G, Taurozzi AJ, Madupe PP, O'Hara MC, Molopyane K, Cappellini E, Hawks J, Skinner MM, Berger L. Human-like enamel growth in Homo naledi. AMERICAN JOURNAL OF BIOLOGICAL ANTHROPOLOGY 2024; 184:e24893. [PMID: 38180115 DOI: 10.1002/ajpa.24893] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/14/2023] [Revised: 11/12/2023] [Accepted: 12/14/2023] [Indexed: 01/06/2024]
Abstract
OBJECTIVES A modern pattern (rate and duration) of dental development occurs relatively recently during human evolution. Given the temporal overlap of Homo naledi with the first appearance of fossil Homo sapiens in Africa, this small-bodied and small-brained hominin presents an opportunity to elucidate the evolution of enamel growth in the hominin clade. Here we conduct the first histological study of two permanent mandibular canines and one permanent maxillary first molar, representing three individuals attributed to H. naledi. We reconstruct the rate and duration of enamel growth and compare these findings to those reported for other fossil hominins and recent humans. MATERIALS AND METHODS Thin sections of each tooth were produced using standard histological methods. Daily and longer period incremental markings were measured to reconstruct enamel secretion and extension rates, Retzius periodicity, canine crown and molar cusp formation time. RESULTS Daily enamel secretion rates overlapped with those from recent hominins. Canine crown formation time is similar to that observed in recent Europeans but is longer than canine formation times reported for most other hominins including Australopithecus and H. neanderthalensis. The extended period of canine formation appears to be due to a relatively tall enamel crown and a sustained slow rate of enamel extension in the cervical portion of the crown. A Retzius periodicity of 11 days for the canines, and nine days for the molar, in H. naledi parallel results found in recent humans. An 11-day periodicity has not been reported for Late Pleistocene Homo (H. erectus, H. neanderthalensis) and is rarely found in Australopithecus and Paranthropus species. DISCUSSION Enamel growth of H. naledi is most similar to recent humans though comparative data are limited for most fossil hominin species. The high Retzius periodicity values do not follow expectations for a small-brained hominin.
Collapse
Affiliation(s)
- Patrick Mahoney
- Skeletal Biology Research Centre, School of Anthropology and Conservation, University of Kent, Canterbury, UK
| | - Gina McFarlane
- Skeletal Biology Research Centre, School of Anthropology and Conservation, University of Kent, Canterbury, UK
| | - Alberto J Taurozzi
- Section for GeoGenetics, Globe Institute, University of Copenhagen, Copenhagen, Denmark
| | - Palesa P Madupe
- Section for GeoGenetics, Globe Institute, University of Copenhagen, Copenhagen, Denmark
- Human Evolution Research Institute, University of Cape Town, Rondebosch, South Africa
| | - Mackie C O'Hara
- Skeletal Biology Research Centre, School of Anthropology and Conservation, University of Kent, Canterbury, UK
| | - Keneiloe Molopyane
- Centre for the Exploration of the Deep Human Journey, University of the Witwatersrand, Johannesburg, South Africa
- The National Geographic Society, Washington, District of Columbia, USA
| | - Enrico Cappellini
- Section for GeoGenetics, Globe Institute, University of Copenhagen, Copenhagen, Denmark
| | - John Hawks
- Centre for the Exploration of the Deep Human Journey, University of the Witwatersrand, Johannesburg, South Africa
- Department of Anthropology, University of Wisconsin-Madison, USA
| | - Matthew M Skinner
- Skeletal Biology Research Centre, School of Anthropology and Conservation, University of Kent, Canterbury, UK
| | - Lee Berger
- Centre for the Exploration of the Deep Human Journey, University of the Witwatersrand, Johannesburg, South Africa
- The National Geographic Society, Washington, District of Columbia, USA
- The Carnegie Institution for Science, Washington, District of Columbia, USA
| |
Collapse
|
3
|
Modesto-Mata M, de la Fuente Valentín L, Hlusko LJ, Martínez de Pinillos M, Towle I, García-Campos C, Martinón-Torres M, Bermúdez de Castro JM. Artificial neural networks reconstruct missing perikymata in worn teeth. Anat Rec (Hoboken) 2024. [PMID: 38468123 DOI: 10.1002/ar.25416] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2023] [Revised: 02/08/2024] [Accepted: 02/11/2024] [Indexed: 03/13/2024]
Abstract
Dental evolutionary studies in hominins are key to understanding how our ancestors and close fossil relatives grew from the early stages of embryogenesis into adults. In a sense, teeth are like an airplane's 'black box' as they record important variables for assessing developmental timing, enabling comparisons within and between populations, species, and genera. The ability to discern this type of nuanced information is embedded in the nature of how tooth enamel and dentin form: incrementally and over years. This incremental growth leaves chronological indicators in the histological structure of enamel, visible on the crown surface as perikymata. These structures are used in the process of reconstructing the rate and timing of tooth formation. Unfortunately, the developmentally earliest growth lines in lateral enamel are quickly lost to wear once the tooth crown erupts. We developed a method to reconstruct these earliest, missing perilymata from worn teeth through knowledge of the later-developed, visible perikymata for all tooth types (incisors, canines, premolars, and molars) using a modern human dataset. Building on our previous research using polynomial regressions, here we describe an artificial neural networks (ANN) method. This new ANN method mostly predicts within 2 counts the number of perikymata present in each of the first three deciles of the crown height for all tooth types. Our ANN method for estimating perikymata lost through wear has two immediate benefits: more accurate values can be produced and worn teeth can be included in dental research. This tool is available on the open-source platform R within the package teethR released under GPL v3.0 license, enabling other researchers the opportunity to expand their datasets for studies of periodicity in histological growth, dental development, and evolution.
Collapse
Affiliation(s)
- Mario Modesto-Mata
- Centro Nacional de Investigación sobre la Evolución Humana (CENIEH), Burgos, Spain
- Universidad Internacional de La Rioja (UNIR), Logroño (La Rioja), Spain
| | | | - Leslea J Hlusko
- Centro Nacional de Investigación sobre la Evolución Humana (CENIEH), Burgos, Spain
| | - Marina Martínez de Pinillos
- Centro Nacional de Investigación sobre la Evolución Humana (CENIEH), Burgos, Spain
- Laboratorio de Evolución Humana (LEH), Universidad de Burgos, Burgos, Spain
| | - Ian Towle
- Centro Nacional de Investigación sobre la Evolución Humana (CENIEH), Burgos, Spain
| | - Cecilia García-Campos
- Centro Nacional de Investigación sobre la Evolución Humana (CENIEH), Burgos, Spain
- Facultad de Ciencias, Universidad Autónoma de Madrid, Ciudad Universitaria de Cantoblanco, Madrid, Spain
| | - María Martinón-Torres
- Centro Nacional de Investigación sobre la Evolución Humana (CENIEH), Burgos, Spain
- Department of Anthropology, University College London, London, UK
| | - José María Bermúdez de Castro
- Centro Nacional de Investigación sobre la Evolución Humana (CENIEH), Burgos, Spain
- Department of Anthropology, University College London, London, UK
| |
Collapse
|
4
|
Hu R, Du B, Zhao L. Retzius periodicity in the Late Miocene hominoid Lufengpithecus lufengensis from Southwest China: Implications for dental development and life history. J Hum Evol 2023; 181:103400. [PMID: 37307694 DOI: 10.1016/j.jhevol.2023.103400] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2022] [Revised: 05/13/2023] [Accepted: 05/13/2023] [Indexed: 06/14/2023]
Affiliation(s)
- Rong Hu
- Institute of Anthropology, School of Sociology and Anthropology, Xiamen University, Xiamen, 361005, China
| | - Baopu Du
- Department of Anatomy, Histology and Embryology, Capital Medical University, Beijing, 100069, China
| | - Lingxia Zhao
- Key Laboratory of Vertebrate Evolution and Human Origins of Chinese Academy of Sciences, Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, Beijing, 100044, China; CAS Center for Excellence in Life and Paleoenvironment, Beijing, 100044, China.
| |
Collapse
|
5
|
Emken S, Witzel C, Kierdorf U, Frölich K, Kierdorf H. Wild boar versus domestic pig-Deciphering of crown growth in porcine second molars. J Anat 2023; 242:1078-1095. [PMID: 36774334 PMCID: PMC10184542 DOI: 10.1111/joa.13838] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2022] [Revised: 01/15/2023] [Accepted: 01/18/2023] [Indexed: 02/13/2023] Open
Abstract
Based on the previously established periodicity of enamel growth marks, we reconstructed crown growth parameters of mandibular second molars from two wild boar and two domestic pigs of the Linderöd breed. Body weight gain and progression of dental development were markedly faster in the domestic pigs than the wild boar. While the final crown dimensions of the M2 did not differ between domestic pigs and wild boar, mean crown formation time (CFT) of this tooth was considerably shorter in the domestic pigs (162 days) than in the wild boar (205 days). The difference in CFT was mainly attributable to a higher enamel extension rate (EER) in the domestic pig. Generally, EER was highest in the cuspalmost deciles of the length of the enamel-dentine-junction and markedly dropped in cervical direction, with lowest values occurring in the cervicalmost decile. In consequence, the cuspal half of the M2 crown was formed about three times faster than the cervical half. In contrast to the EER, no marked difference in daily enamel secretion rate (DSR) was recorded between domestic pigs and wild boar. The duration of enamel matrix apposition as well as linear enamel thickness in corresponding crown portions was only slightly lower in the domestic pigs than the wild boar. Thus, the earlier completion of M2 crown growth in the domestic pig was mainly achieved by a higher EER and not by an increased DSR. The more rapid recruitment of secretory ameloblasts in the course of molar crown formation of domestic pigs compared to wild boar is considered a side-effect of the selection for rapid body growth during pig domestication.
Collapse
Affiliation(s)
- Simon Emken
- Department of Biology, University of Hildesheim, Hildesheim, Germany
| | - Carsten Witzel
- Department of Biology, University of Hildesheim, Hildesheim, Germany
| | - Uwe Kierdorf
- Department of Biology, University of Hildesheim, Hildesheim, Germany
| | - Kai Frölich
- Department of Biology, University of Hildesheim, Hildesheim, Germany.,Tierpark Arche Warder e.V, Warder, Germany
| | - Horst Kierdorf
- Department of Biology, University of Hildesheim, Hildesheim, Germany
| |
Collapse
|
6
|
Mahoney P, McFarlane G, Loch C, White S, Floyd B, Dunn EC, Pitfield R, Nava A, Guatelli-Steinberg D. Dental biorhythm is associated with adolescent weight gain. COMMUNICATIONS MEDICINE 2022; 2:99. [PMID: 36016726 PMCID: PMC9395425 DOI: 10.1038/s43856-022-00164-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2022] [Accepted: 07/26/2022] [Indexed: 12/02/2022] Open
Abstract
Background Evidence of a long-period biological rhythm present in mammalian hard tissue relates to species average body mass. Studies have just begun to investigate the role of this biorhythm in human physiology. Methods The biorhythm is calculated from naturally exfoliated primary molars for 61 adolescents. We determine if the timing relates to longitudinal measures of their weight, height, lower leg length and body mass collected over 14 months between September 2019 to October 2020. We use univariate and multivariate statistical analyses to isolate and identify relationships with the biorhythm. Results Participants with a faster biorhythm typically weigh less each month and gain significantly less weight and mass over 14-months, relative to those with a slower biorhythm. The biorhythm relates to sex differences in weight gain. Conclusions We identify a previously unknown factor that associates with the rapid change in body size that accompanies human adolescence. Our findings provide a basis from which to explore novel relationships between the biorhythm and weight-related health risks. The human body undergoes cyclic changes such as the daily cycle of sleeping and waking, and monthly menstruation. This study calculated one cycle that can be tracked through the growth of children’s milk teeth. The timing of the cycle in different children was compared to changes in body size that occurred when these children were in puberty. A link was seen between the children’s cycle and the weight they gained over 14-months. Adolescents with a faster cycle typically weighed less each month and gained less weight over 14 months compared to those with a slower cycle. Mahoney et al. calculate the long-term biorhythm of adolescents from primary molar teeth and examine the relationship with weight, height and mass. Faster biorhythms are associated with a lower weight, and reduced weight and mass gain during adolescence.
Collapse
|
7
|
Distinguishing primate taxa with enamel incremental variables. J Hum Evol 2022; 164:103139. [PMID: 35123173 DOI: 10.1016/j.jhevol.2021.103139] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2020] [Revised: 12/23/2021] [Accepted: 12/23/2021] [Indexed: 11/23/2022]
Abstract
Enamel has long been of interest for its functional and phylogenetic significance among fossil hominins and other primates. Previous studies demonstrated that enamel incremental features distinguish among hominin fossil taxa, suggesting utility for highlighting taxonomy. However, not all features appear to be useful in mixed samples of fossils, living humans, and apes. Here we tested enamel incremental data from closely related primate taxa to determine which features, if any, distinguish among them. Enamel incremental variables were measured from the M2 of 40 living primate taxa, and we tested our variables using discriminant function analysis at the taxonomic ranks of parvorder, family, tribe, and genus. We then included enamel incremental data from Australopithecus afarensis, Australopithecus africanus, Paranthropus aethiopicus, Paranthropus boisei, and Paranthropus robustus to determine if these features distinguished fossil taxa from living humans and apes. Our initial results show that enamel incremental variables distinguish among primate taxa, but with low classification rates. Further testing with jackknifing methods shows overlap between groups at all taxonomic ranks, suggesting enamel incremental variables are unreliable for taxonomy. The addition of many common enamel incremental growth variables also resulted in multicollinearity in our multivariate analysis. As the dentition and isolated teeth remain a significant portion of the hominin fossil record, verifying enamel incremental features as a useful taxonomic tool is fundamentally important for hominin paleobiology.
Collapse
|
8
|
Geissler E, McGraw WS, Daegling DJ. Dentin hardness differences across various mammalian taxa. J Morphol 2021; 283:109-122. [PMID: 34787915 DOI: 10.1002/jmor.21430] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2021] [Revised: 11/10/2021] [Accepted: 11/14/2021] [Indexed: 11/11/2022]
Abstract
Differences in dentin microstructure have been used as a tool for dietary reconstruction; however, the extent that diet is associated with this aspect of dental morphology has yet to be empirically tested. We conducted microhardness tests of mammalian dentin sections, hypothesizing that species with adaptations to particularly hard diets would have softer dentin, owing to a higher proportion of soft intertubular dentin. Species adapted to abrasive diets, in contrast, should have harder dentin, resulting from a higher proportion of hypermineralized peritubular dentin. We examined molar dentin hardness in ten mammalian taxa with durophagous diets, abrasive diets, and a comparative "control" group of mechanical generalists. Samples included six primate taxa and four non-primate species representing various dietary regimes. Our results reveal significant variation among taxa in overall hardness, but the data do not distinguish between hard and abrasive diets. Several taxa with generalized (i.e., mechanically diverse) diets resemble each other in exhibiting large variance in hardness measurements and comparably soft dentin. The high variation in these species appears to be either a functional signal supporting the niche variation hypothesis or indicate the absence of sustained unidirectional selective pressure. A possible phylogenetic signal of dentin hardness in the data also holds promise for future systematic investigations.
Collapse
Affiliation(s)
- Elise Geissler
- Department of Anthropology, University of Florida, Gainesville, Florida, USA
| | - W Scott McGraw
- Department of Anthropology, The Ohio State University, Columbus, Ohio, USA
| | - David J Daegling
- Department of Anthropology, University of Florida, Gainesville, Florida, USA
| |
Collapse
|
9
|
Vacková S, Králík M, Marečková K, Ráčková L, Quade L, Sedláčková L, Fojtík P, Kučera L. Human “barcode”: Link between phosphate intensity changes in human enamel and light microscopy record of accentuated lines. Microchem J 2021. [DOI: 10.1016/j.microc.2021.106370] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
|
10
|
Lemmers SAM, Dirks W, Street SE, Ngoubangoye B, Herbert A, Setchell JM. Dental microstructure records life history events: A histological study of mandrills (Mandrillus sphinx) from Gabon. J Hum Evol 2021; 158:103046. [PMID: 34332420 DOI: 10.1016/j.jhevol.2021.103046] [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: 12/08/2020] [Revised: 06/18/2021] [Accepted: 06/19/2021] [Indexed: 11/16/2022]
Abstract
Accentuated lines in dental microstructure are hypothesized to correlate with potentially stressful life history events, but our understanding of when, how and why such accentuated lines form in relation to stressful events is limited. We examined accentuated line formation and life history events in the teeth of three naturally deceased mandrills (Mandrillus sphinx, Cercopithecidae), for whom we had detailed life history information. We determined the ages at formation of accentuated lines in histological tooth sections and used dates of birth and death to calibrate dental histology to calendar time and individual age. We found accentuated lines that matched their mother's resumption of sexual cycles in two individuals, and possibly in the third individual. The subjects also formed lines when their mothers were mate-guarded by males or wounded. Accentuated lines matched the birth of the next sibling in one of two cases. Both females formed accentuated lines when they experienced their own sexual swelling cycles, but lines did not match all sexual swelling cycles. Mate-guarding matched an accentuated line in one case, but not in another. Lines matched all three parturitions in the two females. Changes in alpha male and captures did not consistently coincide with accentuated line formation, but repeated captures were associated with lines. Using simulated data, we show that the observed number of matches between lines and events would be very unlikely under a null hypothesis of random line formation. Our results support the hypothesis that some life history events are physiologically stressful enough to cause accentuated line formation in teeth. They contribute to our understanding of how primate life histories are recorded during dental development and enhance our ability to use teeth to reconstruct life history in the absence of direct observation.
Collapse
Affiliation(s)
- Simone A M Lemmers
- Department of Anthropology, Durham University, South Road, Durham, DH1 3LE, UK; Science and Technology in Archaeology Research Center, The Cyprus Institute, Nicosia, Cyprus
| | - Wendy Dirks
- Department of Anthropology, Durham University, South Road, Durham, DH1 3LE, UK
| | - Sally E Street
- Department of Anthropology, Durham University, South Road, Durham, DH1 3LE, UK
| | - Barthélemy Ngoubangoye
- Centre de Primatologie, Centre Internationale de Recherches Médicales, Franceville, Gabon
| | - Anaïs Herbert
- Centre de Primatologie, Centre Internationale de Recherches Médicales, Franceville, Gabon
| | - Joanna M Setchell
- Department of Anthropology, Durham University, South Road, Durham, DH1 3LE, UK.
| |
Collapse
|
11
|
Nacarino-Meneses C, Chinsamy A. Mineralized-tissue histology reveals protracted life history in the Pliocene three-toed horse from Langebaanweg (South Africa). Zool J Linn Soc 2021. [DOI: 10.1093/zoolinnean/zlab037] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Abstract
We studied the bone and dental histology of the tri-dactyl equid Eurygnathohippus hooijeri, one of the most iconic mammals found at the world-renowned Pliocene site of Langebaanweg, South Africa, to reconstruct important features of its life history. Our results show that key life-history events, such as weaning, skeletal maturity and reproductive maturity, occurred later in this African hipparionine compared with European three-toed equids and several extant Equus. Its late life-history schedule agrees with an ecological context of low adult extrinsic mortality and low juvenile survival rates. We also observed high rates of bone growth in Eu. hooijeri that were probably achieved through a high-quality diet and plentiful available water. Our research highlights the significance of combining bone and dental histology in the same taxon to obtain refined palaeobiological information about extinct vertebrates.
Collapse
Affiliation(s)
- Carmen Nacarino-Meneses
- Department of Biological Sciences, University of Cape Town, Private Bag X3, Rhodes Gift, 7700 Cape Town, South Africa
| | - Anusuya Chinsamy
- Department of Biological Sciences, University of Cape Town, Private Bag X3, Rhodes Gift, 7700 Cape Town, South Africa
| |
Collapse
|
12
|
Edgar HJH, Moes E, Willermet C, S Ragsdale C. Conventional microscopy makes perikymata count and spacing data feasible for large samples. AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY 2021; 176:321-331. [PMID: 34272873 DOI: 10.1002/ajpa.24369] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/23/2020] [Revised: 06/13/2021] [Accepted: 06/27/2021] [Indexed: 12/20/2022]
Abstract
OBJECTIVES Current methods of quantifying defects of dental enamel (DDE) include either gross or low-level examination for linear enamel hypoplasia, histological analysis of striae of Retzius, or scanning electron microscopy (SEM) of a tooth or a tooth cast. Gross examination has been shown to miss many defects. Other methods can be destructive, require transporting samples, and are expensive. Here, we show that digital light microscopy (DLM) can be used for the analysis of DDE as indicated by widened perikymata spacing (WPS). This method takes advantage of high-power (100×) microscopy, but is non-destructive, can be implemented almost anywhere, and is inexpensive. MATERIALS AND METHODS As proof of concept, we created photomontages of labial surfaces of five human canines from images made using DLM and SEM. We counted and measured the widths of all visible perikymata for each imaging modality and fit measurements to a negative curve representing the expected values for each tooth. We calculated residuals for each measurement. WPS were defined when R2 was in the 90th percentile, and were considered matched in DLM and SEM images when observed within the same decile of the tooth surface. RESULTS There were more WPS detected in the images derived from DLM than from SEM. Overall, the data derived from the two imaging modalities provided similar information about the frequency and timing of stress during dental development. CONCLUSIONS The method described here allows for DDE data acquisition as WPS from large samples, making feasible population-level studies that reflect sophisticated understanding of dental development.
Collapse
Affiliation(s)
- Heather J H Edgar
- Department of Anthropology, University of New Mexico, Albuquerque, New Mexico, USA.,Office of the Medical Investigator, University of New Mexico, Albuquerque, New Mexico, USA
| | - Emily Moes
- Department of Anthropology, University of New Mexico, Albuquerque, New Mexico, USA
| | - Cathy Willermet
- Department of Sociology, Anthropology, and Social Work, Central Michigan University, Mt. Pleasant, Michigan, USA
| | - Corey S Ragsdale
- Department of Anthropology, Southern Illinois University, Edwardsville, Illinois, USA
| |
Collapse
|
13
|
McGrath K, Limmer LS, Lockey AL, Guatelli-Steinberg D, Reid DJ, Witzel C, Bocaege E, McFarlin SC, El Zaatari S. 3D enamel profilometry reveals faster growth but similar stress severity in Neanderthal versus Homo sapiens teeth. Sci Rep 2021; 11:522. [PMID: 33436796 PMCID: PMC7804262 DOI: 10.1038/s41598-020-80148-w] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2020] [Accepted: 12/16/2020] [Indexed: 01/19/2023] Open
Abstract
Early life stress disrupts growth and creates horizontal grooves on the tooth surface in humans and other mammals, yet there is no consensus for their quantitative analysis. Linear defects are considered to be nonspecific stress indicators, but evidence suggests that intermittent, severe stressors create deeper defects than chronic, low-level stressors. However, species-specific growth patterns also influence defect morphology, with faster-growing teeth having shallower defects at the population level. Here we describe a method to measure the depth of linear enamel defects and normal growth increments (i.e., perikymata) from high-resolution 3D topographies using confocal profilometry and apply it to a diverse sample of Homo neanderthalensis and H. sapiens anterior teeth. Debate surrounds whether Neanderthals exhibited modern human-like growth patterns in their teeth and other systems, with some researchers suggesting that they experienced more severe childhood stress. Our results suggest that Neanderthals have shallower features than H. sapiens from the Upper Paleolithic, Neolithic, and medieval eras, mirroring the faster growth rates in Neanderthal anterior teeth. However, when defect depth is scaled by perikymata depth to assess their severity, Neolithic humans have less severe defects, while Neanderthals and the other H. sapiens groups show evidence of more severe early life growth disruptions.
Collapse
Affiliation(s)
- Kate McGrath
- CNRS, MCC, PACEA, UMR 5199, Univ. Bordeaux, Bâtiment B8, Allée Geoffroy Saint-Hilaire, 33615, Pessac, France. .,Department of Anthropology, Center for the Advanced Study of Human Paleobiology, The George Washington University, 800 22nd St. NW, Suite 6000, Washington, DC, 20052, USA.
| | - Laura Sophia Limmer
- Paleoanthropology, Senckenberg Center for Human Evolution and Paleoenvironment, Universität Tübingen, Rümelinstraße 23, 72070, Tübingen, Germany
| | - Annabelle-Louise Lockey
- Paleoanthropology, Senckenberg Center for Human Evolution and Paleoenvironment, Universität Tübingen, Rümelinstraße 23, 72070, Tübingen, Germany
| | - Debbie Guatelli-Steinberg
- Department of Anthropology, Department of Evolution, Ecology and Organismal Biology, The Ohio State University, 4034 Smith Laboratory, 174 W 18th Avenue, Columbus, OH, 43210, USA.,Skeletal Biology Research Centre, School of Anthropology and Conservation, University of Kent, Canterbury, Kent, CT2 7NZ, UK
| | - Donald J Reid
- Department of Anthropology, Center for the Advanced Study of Human Paleobiology, The George Washington University, 800 22nd St. NW, Suite 6000, Washington, DC, 20052, USA
| | - Carsten Witzel
- Department of Biology, Universität Hildesheim, Universitätsplatz 1, 31141, Hildesheim, Germany
| | - Emmy Bocaege
- Skeletal Biology Research Centre, School of Anthropology and Conservation, University of Kent, Canterbury, Kent, CT2 7NZ, UK
| | - Shannon C McFarlin
- Department of Anthropology, Center for the Advanced Study of Human Paleobiology, The George Washington University, 800 22nd St. NW, Suite 6000, Washington, DC, 20052, USA.,Human Origins Program, National Museum of Natural History, Smithsonian Institution, 10th Street & Constitution Avenue NW, Washington, DC, 20560, USA
| | - Sireen El Zaatari
- Paleoanthropology, Senckenberg Center for Human Evolution and Paleoenvironment, Universität Tübingen, Rümelinstraße 23, 72070, Tübingen, Germany
| |
Collapse
|
14
|
McFarlane G, Guatelli-Steinberg D, Loch C, White S, Bayle P, Floyd B, Pitfield R, Mahoney P. An inconstant biorhythm: The changing pace of Retzius periodicity in human permanent teeth. AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY 2020; 175:172-186. [PMID: 33368148 DOI: 10.1002/ajpa.24206] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Revised: 11/06/2020] [Accepted: 12/06/2020] [Indexed: 12/25/2022]
Abstract
OBJECTIVES Human tooth enamel retains evidence of growth in the form of Retzius lines. The number of daily growth increments between the regularly occurring lines defines their repeat interval, or periodicity. Retzius periodicity is often incorporated into enamel formation times, age-at-death reconstructions, or used to provide a basis from which to explore an underlying biorhythm. Biological anthropologists typically assume that RP remains constant within an individual and does not vary along the tooth-row. Here, we test that assumption. MATERIALS AND METHODS RP was calculated from n = 223 thin sections of human permanent teeth from individuals of British and southern African origin. Forty individuals provided multiple teeth (n = 102 teeth) and a further 121 individuals each provided a single tooth. RESULTS We report first evidence that RP of permanent teeth does not always remain constant within an individual. Of those individuals that provided multiple teeth, 42% (n = 17/40) demonstrated a decrease in RP along the tooth row, with most shifting by two or more days (n = 11). Across the entire sample, mean RP of anterior teeth was significantly higher than molars. Mean premolar RP tended to be intermediate between anterior teeth and molars. DISCUSSION Our data do not support the assumption that RP invariably remains constant within the permanent teeth of an individual. Transferring RP from molars to incisors within an individual can result in a miscalculation of formation time and age-at-death by up to 1 year. Implications for biological anthropologists and the source of the underlying long period biorhythm are discussed.
Collapse
Affiliation(s)
- Gina McFarlane
- Human Osteology Lab, School of Anthropology and Conservation, University of Kent, Canterbury, UK
| | - Debbie Guatelli-Steinberg
- Human Osteology Lab, School of Anthropology and Conservation, University of Kent, Canterbury, UK.,Department of Anthropology, The Ohio State University, Columbus, Ohio, USA
| | - Carolina Loch
- Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, New Zealand
| | - Sophie White
- Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, New Zealand
| | | | - Bruce Floyd
- School of Social Sciences, University of Auckland, New Zealand
| | - Rosie Pitfield
- Human Osteology Lab, School of Anthropology and Conservation, University of Kent, Canterbury, UK
| | - Patrick Mahoney
- Human Osteology Lab, School of Anthropology and Conservation, University of Kent, Canterbury, UK
| |
Collapse
|
15
|
A comprehensive survey of Retzius periodicities in fossil hominins and great apes. J Hum Evol 2020; 149:102896. [DOI: 10.1016/j.jhevol.2020.102896] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2019] [Revised: 09/15/2020] [Accepted: 09/15/2020] [Indexed: 10/23/2022]
|
16
|
Hu R, Zhao L. Molar crown formation times of fossil orangutan molars from Guangxi, China. AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY 2020; 174:315-326. [PMID: 33253429 DOI: 10.1002/ajpa.24183] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/08/2020] [Revised: 09/14/2020] [Accepted: 11/09/2020] [Indexed: 11/06/2022]
Abstract
OBJECTIVES We aimed to investigate molar enamel development in fossil orangutans from Guangxi and shed light on the evolution of Asian great apes. MATERIALS AND METHODS We collected 32 fossil orangutan molars, most of which were from Guangxi apothecaries and the Guangxi Daxin Heidong cave, and prepared histological sections of each molar. We then characterized aspects of dental development, including long period line periodicity, number of Retzius lines and lateral enamel formation time, cuspal enamel thickness, and enamel formation time. RESULTS The long period line periodicity in fossil orangutans ranged from 9 to 10 days (mean, 9.09 days). The molar lateral enamel formation time ranged from 1.48 to 3.17 years (540-1,152 days). Cuspal enamel thickness in fossil orangutan molars ranged from 949 to 2,535 μm, and cuspal enamel formation time ranged from 0.64 to 1.87 years. Molar enamel formation time of fossil orangutans ranged from 2.47 to 4.67 years. DISCUSSION Long-period line periodicity of fossil orangutans from Guangxi was within the variation range of extant orangutans, and the average long period line periodicity (9.09 days) of fossil orangutans from Guangxi in this study was lower than the values for extant orangutans (9.5 days) and fossil orangutans (10.9 days) from Sumatra and Vietnam. Orangutan enamel thickness may have gradually decreased from the Middle Pleistocene to Holocene. Crown formation time of fossil orangutans was slightly longer than that of extant orangutans, and the M1 emergence age of fossil orangutans from Guangxi was about 4-6 years. These findings might indicate the regional difference or evolutionary changes in orangutans since Pleistocene. Dental development of the Guangxi fossil orangutans were more similar to that of Asian Miocene apes, suggesting the closer evolutionary relationship of orangutans to Miocene Asian fossil apes.
Collapse
Affiliation(s)
- Rong Hu
- Institute of Anthropology, Department of Anthropology and Ethology, Xiamen University, Xiamen, China
| | - Lingxia Zhao
- Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Science, Beijing, China
| |
Collapse
|
17
|
Tsutaya T. Blurred time resolution of tooth dentin serial sections. AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY 2020; 173:748-759. [DOI: 10.1002/ajpa.24113] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/04/2020] [Revised: 05/26/2020] [Accepted: 06/09/2020] [Indexed: 11/06/2022]
Affiliation(s)
- Takumi Tsutaya
- Research Institute for Marine Resources Utilization Japan Agency for Marine‐Earth Science and Technology Yokosuka Kanagawa Japan
| |
Collapse
|
18
|
Mahoney P, McFarlane G, Pitfield R, O'Hara MC, Miszkiewicz JJ, Deter C, Seal H, Guatelli-Steinberg D. A structural biorhythm related to human sexual dimorphism. J Struct Biol 2020; 211:107550. [DOI: 10.1016/j.jsb.2020.107550] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2020] [Revised: 06/09/2020] [Accepted: 06/11/2020] [Indexed: 01/26/2023]
|
19
|
Martínez de Pinillos M, Martín-Francés L, de Castro JMB, García-Campos C, Modesto-Mata M, Martinón-Torres M, Vialet A. Inner morphological and metric characterization of the molar remains from the Montmaurin-La Niche mandible: The Neanderthal signal. J Hum Evol 2020; 145:102739. [DOI: 10.1016/j.jhevol.2019.102739] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2019] [Revised: 11/06/2019] [Accepted: 11/20/2019] [Indexed: 10/24/2022]
|
20
|
Papakyrikos AM, Arora M, Austin C, Boughner JC, Capellini TD, Dingwall HL, Greba Q, Howland JG, Kato A, Wang X, Smith TM. Biological clocks and incremental growth line formation in dentine. J Anat 2020; 237:367-378. [PMID: 32266720 PMCID: PMC7369199 DOI: 10.1111/joa.13198] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2020] [Revised: 03/12/2020] [Accepted: 03/16/2020] [Indexed: 01/01/2023] Open
Abstract
Dentine- and enamel-forming cells secrete matrix in consistent rhythmic phases, resulting in the formation of successive microscopic growth lines inside tooth crowns and roots. Experimental studies of various mammals have proven that these lines are laid down in subdaily, daily (circadian), and multidaily rhythms, but it is less clear how these rhythms are initiated and maintained. In 2001, researchers reported that lesioning the so-called master biological clock, the suprachiasmatic nucleus (SCN), halted daily line formation in rat dentine, whereas subdaily lines persisted. More recently, a key clock gene (Bmal1) expressed in the SCN in a circadian manner was also found to be active in dentine- and enamel- secretory cells. To probe these potential neurological and local mechanisms for the production of rhythmic lines in teeth, we reexamined the role of the SCN in growth line formation in Wistar rats and investigated the presence of daily lines in Bmal1 knockout mice (Bmal1-/- ). In contrast to the results of the 2001 study, we found that both daily and subdaily growth lines persisted in rat dentine after complete or partial SCN lesion in the majority of individuals. In mice, after transfer into constant darkness, daily rhythms continued to manifest as incremental lines in the dentine of each Bmal1 genotype (wild-type, Bmal+/- , and Bmal1-/- ). These results affirm that the manifestation of biological rhythms in teeth is a robust phenomenon, imply a more autonomous role of local biological clocks in tooth growth than previously suggested, and underscore the need further to elucidate tissue-specific circadian biology and its role in incremental line formation. Investigations of this nature will strengthen an invaluable system for determining growth rates and calendar ages from mammalian hard tissues, as well as documenting the early lives of fossil hominins and other primates.
Collapse
Affiliation(s)
- Amanda M. Papakyrikos
- Department of AnthropologyWellesley CollegeWellesleyMAUSA
- Department of Developmental BiologyStanford University School of MedicineStanfordCAUSA
| | - Manish Arora
- Department of Environmental Medicine and Public HealthIcahn School of Medicine at Mount SinaiNew YorkNYUSA
| | - Christine Austin
- Department of Environmental Medicine and Public HealthIcahn School of Medicine at Mount SinaiNew YorkNYUSA
| | - Julia C. Boughner
- Department of Anatomy, Physiology and PharmacologyCollege of MedicineUniversity of SaskatchewanSaskatoonSKCanada
| | | | | | - Quentin Greba
- Department of Anatomy, Physiology and PharmacologyCollege of MedicineUniversity of SaskatchewanSaskatoonSKCanada
| | - John G. Howland
- Department of Anatomy, Physiology and PharmacologyCollege of MedicineUniversity of SaskatchewanSaskatoonSKCanada
| | - Akiko Kato
- Department of Human Evolutionary BiologyHarvard UniversityCambridgeMAUSA
- Department of Oral AnatomySchool of DentistryAichi Gakuin UniversityNagoyaJapan
| | - Xiu‐Ping Wang
- Department of Developmental BiologyHarvard School of Dental MedicineBostonMAUSA
| | - Tanya M. Smith
- Department of Human Evolutionary BiologyHarvard UniversityCambridgeMAUSA
- Australian Research Centre for Human EvolutionGriffith UniversityNathanQldAustralia
- Griffith Centre for Social and Cultural ResearchGriffith UniversityNathanQldAustralia
| |
Collapse
|
21
|
Ryan SE, Reynard LM, Pompianu E, van Dommelen P, Murgia C, Subirà ME, Tuross N. Growing up in Ancient Sardinia: Infant-toddler dietary changes revealed by the novel use of hydrogen isotopes (δ2H). PLoS One 2020; 15:e0235080. [PMID: 32639959 PMCID: PMC7343138 DOI: 10.1371/journal.pone.0235080] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2019] [Accepted: 06/08/2020] [Indexed: 11/19/2022] Open
Abstract
Detailed information about the lives and deaths of children in antiquity is often in short supply. Childhood dietary histories are, however, recorded and maintained in the teeth of both juveniles and adults. Primary tooth dentinal collagen does not turn over, preserving a sequential record of dietary changes. The use of nitrogen (δ15N) and carbon (δ13C) isotope values of incrementally sampled dentin are used in the study of breastfeeding practices but evidence for the addition of weaning foods, both in terms of mode and, particularly, duration, has remained analytically inaccessible to date. Here, we demonstrate how the novel use hydrogen isotope (δ2H) values of sequentially micro-sampled dentin collagen, measured from individuals excavated from a Punic cemetery, in Sardinia, Italy, can serve as a proxy for weaning food type and duration in ancient childhood diet. The weaning rate and age, based on the decline in δ15N and δ13C values of permanent first molars and the concomitant increase in δ2H, appears to be broadly similar among six individuals. Hydrogen isotopes vary systematically from a low value soon after birth, rising through early childhood. The early post-birth values can be explained by the influence of 2H-depleted lipids from mother's breastmilk and the later δ2H rise is consistent with, among other things, a substantial portion of boiled foodstuffs, such as the higher δ2H values observed in porridge. Overall δ2H in dentin shows great promise to elucidate infant and childhood feeding practices, and especially the introduction of supplementary foods during the weaning process.
Collapse
Affiliation(s)
- Saskia E. Ryan
- Department of Human Evolutionary Biology, Harvard University, Boston, Massachusetts, Unitied States of America
| | - Linda M. Reynard
- Department of Human Evolutionary Biology, Harvard University, Boston, Massachusetts, Unitied States of America
| | | | - Peter van Dommelen
- Joukowsky Institute for Archaeology and the Ancient World, Brown University, Providence, Rhode Island, United States of America
| | - Clizia Murgia
- Departament de Biologia Animal, Unitat d’Antropologia Biològica, Biologia Vegetal i Ecologia, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - M. Eulàlia Subirà
- Grup de Recerca en Antropologia Biològica, Unitat d’Antropologia Biològica, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Noreen Tuross
- Department of Human Evolutionary Biology, Harvard University, Boston, Massachusetts, Unitied States of America
| |
Collapse
|
22
|
Enamel thickness and dental development in Rudapithecus hungaricus. J Hum Evol 2019; 136:102649. [DOI: 10.1016/j.jhevol.2019.102649] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2019] [Revised: 08/05/2019] [Accepted: 08/05/2019] [Indexed: 11/19/2022]
|
23
|
MacLatchy L, Rossie J, Houssaye A, Olejniczak AJ, Smith TM. New hominoid fossils from Moroto II, Uganda and their bearing on the taxonomic and adaptive status of Morotopithecus bishopi. J Hum Evol 2019; 132:227-246. [PMID: 31203849 DOI: 10.1016/j.jhevol.2019.03.008] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2018] [Revised: 03/05/2019] [Accepted: 03/07/2019] [Indexed: 10/26/2022]
Abstract
The early Miocene site of Moroto II, Uganda has yielded some of the oldest known hominoid fossils. A new partial mandible (UMP MORII 03'551) is notable for its long tooth row and large, narrow M2 with well-developed cristids - a morphological combination previously unknown for large bodied catarrhines of the Early Miocene and suggesting folivory. The tooth proportions are compatible with belonging to the same taxon as the maxilla UMP 62-11, the holotype of Morotopithecus bishopi; likewise, the long tooth row and vertical planum of UMP MORII 03'551 suggest that it may represent the same taxon as mandible(s) UMP 66-01 and UMP 62-10. Canine size strongly suggests UMP MORII 03'551 is a female. Comparisons of the tooth crown morphology and tooth row proportions, relative enamel thickness, enamel-dentine junction morphology, long-period line periodicity, and dental wear patterns support significant morphological, developmental, and inferred dietary differentiation, and therefore generic-level distinctiveness, among Afropithecus, Morotopithecus and the Proconsul clade. An isolated M1 (UMP MORII 03'559) is morphologically dissimilar, and much smaller than the actual or inferred size of molars in UMP MORII 03'551, UMP 66-01 and UMP 62-10, supporting the presence of two hominoid taxa at Moroto II, M. bishopi and a smaller bodied proconsulid. Given the high level of body mass dimorphism inferred for Morotopithecus and other early Miocene catarrhines, the known postcrania from Moroto II could be attributable to either taxon. However, UMP MORII 03'551 and the femora UMP MORII 94'80 derive from the same stratigraphic interval, while the isolated M1 was deposited later, increasing the likelihood that the mandible and femora are from the same individual. These new fossils expand our understanding of the taxonomic and adaptive diversity of early Miocene catarrhines.
Collapse
Affiliation(s)
- Laura MacLatchy
- Department of Anthropology, University of Michigan, Ann Arbor, MI 48104, USA.
| | - James Rossie
- Department of Anthropology, S.U.N.Y. Stony Brook, Stony Brook, NY 11794, USA
| | - Alexandra Houssaye
- UMR 7179 CNRS/Muséum National d'Histoire Naturelle, Département Adaptations du Vivant, 57 Rue Cuvier CP-55, 75005 Paris, France
| | | | - Tanya M Smith
- Department of Human Evolutionary Biology, Harvard University, 11 Divinity Avenue, Cambridge, MA 02138, USA
| |
Collapse
|
24
|
Kierdorf H, Breuer F, Witzel C, Kierdorf U. Pig enamel revisited – Incremental markings in enamel of wild boars and domestic pigs. J Struct Biol 2019; 205:48-59. [DOI: 10.1016/j.jsb.2018.11.009] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2018] [Revised: 11/19/2018] [Accepted: 11/21/2018] [Indexed: 10/27/2022]
|
25
|
Smith TM, Houssaye A, Kullmer O, Le Cabec A, Olejniczak AJ, Schrenk F, de Vos J, Tafforeau P. Disentangling isolated dental remains of Asian Pleistocene hominins and pongines. PLoS One 2018; 13:e0204737. [PMID: 30383758 PMCID: PMC6211657 DOI: 10.1371/journal.pone.0204737] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2018] [Accepted: 09/13/2018] [Indexed: 11/18/2022] Open
Abstract
Scholars have debated the taxonomic identity of isolated primate teeth from the Asian Pleistocene for over a century, which is complicated by morphological and metric convergence between orangutan (Pongo) and hominin (Homo) molariform teeth. Like Homo erectus, Pongo once showed considerable dental variation and a wide distribution throughout mainland and insular Asia. In order to clarify the utility of isolated dental remains to document the presence of hominins during Asian prehistory, we examined enamel thickness, enamel-dentine junction shape, and crown development in 33 molars from G. H. R. von Koenigswald's Chinese Apothecary collection (11 Sinanthropus officinalis [= Homo erectus], 21 "Hemanthropus peii," and 1 "Hemanthropus peii" or Pongo) and 7 molars from Sangiran dome (either Homo erectus or Pongo). All fossil teeth were imaged with non-destructive conventional and/or synchrotron micro-computed tomography. These were compared to H. erectus teeth from Zhoukoudian, Sangiran and Trinil, and a large comparative sample of fossil Pongo, recent Pongo, and recent human teeth. We find that Homo and Pongo molars overlap substantially in relative enamel thickness; molar enamel-dentine junction shape is more distinctive, with Pongo showing relatively shorter dentine horns and wider crowns than Homo. Long-period line periodicity values are significantly greater in Pongo than in H. erectus, leading to longer crown formation times in the former. Most of the sample originally assigned to S. officinalis and H. erectus shows greater affinity to Pongo than to the hominin comparative sample. Moreover, enamel thickness, enamel-dentine junction shape, and a long-period line periodicity value in the "Hemanthropus peii" sample are indistinguishable from fossil Pongo. These results underscore the need for additional recovery and study of associated dentitions prior to erecting new taxa from isolated teeth.
Collapse
Affiliation(s)
- Tanya M. Smith
- Australian Research Centre for Human Evolution, Griffith University, Nathan, Queensland, Australia
- Department of Human Evolutionary Biology, Harvard University, Cambridge, Massachusetts, United States of America
| | - Alexandra Houssaye
- Department of Human Evolutionary Biology, Harvard University, Cambridge, Massachusetts, United States of America
- ESRF—The European Synchrotron, Grenoble, France
- Département Adaptations du Vivant, UMR 7179 CNRS, Muséum National d’Histoire Naturelle, Paris, France
| | - Ottmar Kullmer
- Department of Paleoanthropology, Senckenberg Research Institute and Natural History Museum Frankfurt, Frankfurt a.M., Germany
- Department of Paleobiology and Environment, Institute of Ecology, Evolution, and Diversity, Johann Wolfgang Goethe University, Frankfurt a.M., Germany
| | - Adeline Le Cabec
- Department of Human Evolutionary Biology, Harvard University, Cambridge, Massachusetts, United States of America
- ESRF—The European Synchrotron, Grenoble, France
- Department of Human Evolution, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany
| | | | - Friedemann Schrenk
- Department of Paleoanthropology, Senckenberg Research Institute and Natural History Museum Frankfurt, Frankfurt a.M., Germany
- Department of Paleobiology and Environment, Institute of Ecology, Evolution, and Diversity, Johann Wolfgang Goethe University, Frankfurt a.M., Germany
| | - John de Vos
- Department of Geology, Naturalis Biodiversity Center, Leiden, The Netherlands
| | | |
Collapse
|
26
|
O'Meara RN, Dirks W, Martinelli AG. Enamel formation and growth in non-mammalian cynodonts. ROYAL SOCIETY OPEN SCIENCE 2018; 5:172293. [PMID: 29892415 PMCID: PMC5990740 DOI: 10.1098/rsos.172293] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2017] [Accepted: 04/13/2018] [Indexed: 06/01/2023]
Abstract
The early evolution of mammals is associated with the linked evolutionary origin of diphyodont tooth replacement, rapid juvenile growth and determinate adult growth. However, specific relationships among these characters during non-mammalian cynodont evolution require further exploration. Here, polarized light microscopy revealed incremental lines, resembling daily laminations of extant mammals, in histological sections of enamel in eight non-mammalian cynodont species. In the more basal non-probainognathian group, enamel extends extremely rapidly from cusp to cervix. By contrast, the enamel of mammaliamorphs is gradually accreted, with slow rates of crown extension, more typical of the majority of non-hypsodont crown mammals. These results are consistent with the reduction in dental replacement rate across the non-mammalian cynodont lineage, with greater rates of crown extension required in most non-probainognathians, and slower crown extension rates permitted in mammaliamorphs, which have reduced patterns of dental replacement in comparison with many non-probainognathians. The evolution of mammal-like growth patterns, with faster juvenile growth and more abruptly terminating adult growth, is linked with this reduction in dental replacement rates and may provide an additional explanation for the observed pattern in enamel growth rates. It is possible that the reduction in enamel extension rates in mammaliamorphs reflects an underlying reduction in skeletal growth rates at the time of postcanine formation, due to a more abruptly terminating pattern of adult growth in these more mammal-like, crownward species.
Collapse
Affiliation(s)
- Rachel N. O'Meara
- The University Museum of Zoology, Downing Street, Cambridge CB2 3EJ, UK
| | - Wendy Dirks
- Department of Anthropology, Durham University, Dawson Building, South Road, Durham DH1 3LE, UK
| | - Agustín G. Martinelli
- Departamento de Geociências, Universidade Federal do Rio Grande do Sul, Ave. Bento Gonçalves 9500, 91540-000 Porto Alegre, Rio Grande do Sul, Brazil
- Sección Paleontología de Vertebrados, Museo Argentino de Ciencias Naturales ‘Bernardino Rivadavia’, Av. Ángel Gallardo 470, Buenos Aires C1405DJR, Argentina
| |
Collapse
|
27
|
Waugh DA, Suydam RS, Ortiz JD, Thewissen JGM. Validation of Growth Layer Group (GLG) depositional rate using daily incremental growth lines in the dentin of beluga (Delphinapterus leucas (Pallas, 1776)) teeth. PLoS One 2018; 13:e0190498. [PMID: 29338011 PMCID: PMC5770016 DOI: 10.1371/journal.pone.0190498] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2017] [Accepted: 12/15/2017] [Indexed: 12/04/2022] Open
Abstract
Counts of Growth Layer Groups (GLGs) in the dentin of marine mammal teeth are widely used as indicators of age. In most marine mammals, observations document that GLGs are deposited yearly, but in beluga whales, some studies have supported the view that two GLGs are deposited each year. Our understanding of beluga life-history differs substantially depending on assumptions regarding the timing of GLG deposition; therefore, resolving this issue has important considerations for population assessments. In this study, we used incremental lines that represent daily pulses of dentin mineralization to test the hypothesis that GLGs in beluga dentin are deposited on a yearly basis. Our estimate of the number of daily growth lines within one GLG is remarkably close to 365 days within error, supporting the hypothesis that GLGs are deposited annually in beluga. We show that measurement of daily growth increments can be used to validate the time represented by GLGs in beluga. Furthermore, we believe this methodology may have broader applications to age estimation in other taxa.
Collapse
Affiliation(s)
- David A. Waugh
- Department of Anatomy and Neurobiology, Northeast Ohio Medical University, Rootstown, Ohio, United States of America
- * E-mail:
| | - Robert S. Suydam
- North Slope Borough, Department of Wildlife Management, Barrow, Alaska, United States of America
| | - Joseph D. Ortiz
- Department of Geology, Kent State University, Kent, Ohio, United States of America
| | - J. G. M. Thewissen
- Department of Anatomy and Neurobiology, Northeast Ohio Medical University, Rootstown, Ohio, United States of America
| |
Collapse
|
28
|
Mahoney P, Miszkiewicz JJ, Chapple S, Le Luyer M, Schlecht SH, Stewart TJ, Griffiths RA, Deter C, Guatelli‐Steinberg D. The biorhythm of human skeletal growth. J Anat 2018; 232:26-38. [PMID: 29023695 PMCID: PMC5735060 DOI: 10.1111/joa.12709] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/23/2017] [Indexed: 12/15/2022] Open
Abstract
Evidence of a periodic biorhythm is retained in tooth enamel in the form of Retzius lines. The periodicity of Retzius lines (RP) correlates with body mass and the scheduling of life history events when compared between some mammalian species. The correlation has led to the development of the inter-specific Havers-Halberg oscillation (HHO) hypothesis, which holds great potential for studying aspects of a fossil species biology from teeth. Yet, our understanding of if, or how, the HHO relates to human skeletal growth is limited. The goal here is to explore associations between the biorhythm and two hard tissues that form at different times during human ontogeny, within the context of the HHO. First, we investigate the relationship of RP to permanent molar enamel thickness and the underlying daily rate that ameloblasts secrete enamel during childhood. Following this, we develop preliminary research conducted on small samples of adult human bone by testing associations between RP, adult femoral length (as a proxy for attained adult stature) and cortical osteocyte lacunae density (as a proxy for the rate of osteocyte proliferation). Results reveal RP is positively correlated with enamel thickness, negatively correlated with femoral length, but weakly associated with the rate of enamel secretion and osteocyte proliferation. These new data imply that a slower biorhythm predicts thicker enamel for children but shorter stature for adults. Our results develop the intra-specific HHO hypothesis suggesting that there is a common underlying systemic biorhythm that has a role in the final products of human enamel and bone growth.
Collapse
Affiliation(s)
- Patrick Mahoney
- Human Osteology LabSkeletal Biology Research CentreSchool of Anthropology and ConservationUniversity of KentCanterburyUK
| | - Justyna J. Miszkiewicz
- Skeletal Biology and Forensic Anthropology Research GroupSchool of Archaeology and AnthropologyAustralian National UniversityCanberraACTAustralia
| | - Simon Chapple
- Human Osteology LabSkeletal Biology Research CentreSchool of Anthropology and ConservationUniversity of KentCanterburyUK
| | - Mona Le Luyer
- Human Osteology LabSkeletal Biology Research CentreSchool of Anthropology and ConservationUniversity of KentCanterburyUK
- De la Prehistoire à l'Actuel: CultureEnvironment et Anthropologie (UMR 5199 PACEA)Université de BordeauxPessacFrance
| | | | - Tahlia J. Stewart
- Skeletal Biology and Forensic Anthropology Research GroupSchool of Archaeology and AnthropologyAustralian National UniversityCanberraACTAustralia
| | - Richard A. Griffiths
- Durrell Institute of Conservation and EcologySchool of Anthropology and ConservationUniversity of KentCanterburyUK
| | - Chris Deter
- Human Osteology LabSkeletal Biology Research CentreSchool of Anthropology and ConservationUniversity of KentCanterburyUK
| | | |
Collapse
|
29
|
Nacarino-Meneses C, Jordana X, Orlandi-Oliveras G, Köhler M. Reconstructing molar growth from enamel histology in extant and extinct Equus. Sci Rep 2017; 7:15965. [PMID: 29162890 PMCID: PMC5698294 DOI: 10.1038/s41598-017-16227-2] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2017] [Accepted: 11/09/2017] [Indexed: 11/26/2022] Open
Abstract
The way teeth grow is recorded in dental enamel as incremental marks. Detailed analysis of tooth growth is known to provide valuable insights into the growth and the pace of life of vertebrates. Here, we study the growth pattern of the first lower molar in several extant and extinct species of Equus and explore its relationship with life history events. Our histological analysis shows that enamel extends beyond the molar’s cervix in these mammals. We identified three different crown developmental stages (CDS) in the first lower molars of equids characterised by different growth rates and likely to be related to structural and ontogenetic modifications of the tooth. Enamel extension rate, which ranges from ≈400 μm/d at the beginning of crown development to rates of ≈30 μm/d near the root, and daily secretion rate (≈17 μm/d) have been shown to be very conservative within the genus. From our results, we also inferred data of molar wear rate for these equids that suggest higher wear rates at early ontogenetic stages (13 mm/y) than commonly assumed. The results obtained here provide a basis for future studies of equid dentition in different scientific areas, involving isotope, demographic and dietary studies.
Collapse
Affiliation(s)
- Carmen Nacarino-Meneses
- Institut Català de Paleontologia Miquel Crusafont (ICP), Campus de la Universitat Autònoma de Barcelona, 08193 Bellaterra, Barcelona, Spain.
| | - Xavier Jordana
- Unitat d'Antropologia Biològica, BABVE department, Universitat Autònoma de Barcelona (UAB), 08193 Bellaterra, Barcelona, Spain
| | - Guillem Orlandi-Oliveras
- Institut Català de Paleontologia Miquel Crusafont (ICP), Campus de la Universitat Autònoma de Barcelona, 08193 Bellaterra, Barcelona, Spain
| | - Meike Köhler
- Institut Català de Paleontologia Miquel Crusafont (ICP), Campus de la Universitat Autònoma de Barcelona, 08193 Bellaterra, Barcelona, Spain.,ICREA, Pg. Lluís Companys 23, 08010, Barcelona, Spain
| |
Collapse
|
30
|
Green DR, Green GM, Colman AS, Bidlack FB, Tafforeau P, Smith TM. Synchrotron imaging and Markov Chain Monte Carlo reveal tooth mineralization patterns. PLoS One 2017; 12:e0186391. [PMID: 29049333 PMCID: PMC5648163 DOI: 10.1371/journal.pone.0186391] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2017] [Accepted: 09/29/2017] [Indexed: 11/29/2022] Open
Abstract
The progressive character of tooth formation records aspects of mammalian life history, diet, seasonal behavior and climate. Tooth mineralization occurs in two stages: secretion and maturation, which overlap to some degree. Despite decades of study, the spatial and temporal pattern of elemental incorporation during enamel mineralization remains poorly characterized. Here we use synchrotron X-ray microtomography and Markov Chain Monte Carlo sampling to estimate mineralization patterns from an ontogenetic series of sheep molars (n = 45 M1s, 18 M2s). We adopt a Bayesian approach that posits a general pattern of maturation estimated from individual- and population-level mineral density variation over time. This approach converts static images of mineral density into a dynamic model of mineralization, and demonstrates that enamel secretion and maturation waves advance at nonlinear rates with distinct geometries. While enamel secretion is ordered, maturation geometry varies within a population and appears to be driven by diffusive processes. Our model yields concrete expectations for the integration of physiological and environmental signals, which is of particular significance for paleoseasonality research. This study also provides an avenue for characterizing mineralization patterns in other taxa. Our synchrotron imaging data and model are available for application to multiple disciplines, including health, material science, and paleontological research.
Collapse
Affiliation(s)
- Daniel R. Green
- Department of Human Evolutionary Biology, Harvard University, Cambridge, Massachusetts, United States of America
- Forsyth Institute, Cambridge, Massachusetts, United States of America
- * E-mail:
| | - Gregory M. Green
- Physics Department, Stanford University, Palo Alto, California, United States of America
- Kavli Institute for Particle Physics and Cosmology, Stanford University, Palo Alto, California, United States of America
| | - Albert S. Colman
- Department of the Geophysical Sciences, University of Chicago, Chicago, Illinois, United States of America
| | | | - Paul Tafforeau
- European Synchrotron Radiation Facility, Grenoble, France
| | - Tanya M. Smith
- Department of Human Evolutionary Biology, Harvard University, Cambridge, Massachusetts, United States of America
- Australian Research Center for Human Evolution, Griffith University, Brisbane, Australia
| |
Collapse
|
31
|
Nava A, Coppa A, Coppola D, Mancini L, Dreossi D, Zanini F, Bernardini F, Tuniz C, Bondioli L. Virtual histological assessment of the prenatal life history and age at death of the Upper Paleolithic fetus from Ostuni (Italy). Sci Rep 2017; 7:9427. [PMID: 28842603 PMCID: PMC5572742 DOI: 10.1038/s41598-017-09773-2] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2017] [Accepted: 07/31/2017] [Indexed: 01/08/2023] Open
Abstract
The fetal remains from the Ostuni 1 burial (Italy, ca 27 ka) represent a unique opportunity to explore the prenatal biological parameters, and to reconstruct the possible patho-biography, of a fetus (and its mother) in an Upper Paleolithic context. Phase-contrast synchrotron X-ray microtomography imaging of two deciduous tooth crowns and microfocus CT measurements of the right hemimandible of the Ostuni 1b fetus were performed at the SYRMEP beamline and at the TomoLab station of the Elettra - Sincrotrone laboratory (Trieste, Italy) in order to refine age at death and to report the enamel developmental history and dental tissue volumes for this fetal individual. The virtual histology allowed to estimate the age at death of the fetus at 31–33 gestational weeks. Three severe physiological stress episodes were also identified in the prenatal enamel. These stress episodes occurred during the last two months and half of pregnancy and may relate to the death of both individuals. Compared with modern prenatal standards, Os1b’s skeletal development was advanced. This cautions against the use of modern skeletal and dental references for archaeological finds and emphasizes the need for more studies on prenatal archaeological skeletal samples.
Collapse
Affiliation(s)
- Alessia Nava
- Dipartimento di Biologia Ambientale, Università di Roma "La Sapienza", Rome, Italy. .,Servizio di Bioarcheologia, Museo delle Civiltà, Rome, Italy.
| | - Alfredo Coppa
- Dipartimento di Biologia Ambientale, Università di Roma "La Sapienza", Rome, Italy
| | - Donato Coppola
- Università degli Studi di Bari "Aldo Moro", Bari, Italy.,Museo di Civiltà Preclassiche della Murgia Meridionale, Ostuni, Italy
| | - Lucia Mancini
- Elettra - Sincrotrone Trieste S.C.p.A., Basovizza, Trieste, Italy
| | - Diego Dreossi
- Elettra - Sincrotrone Trieste S.C.p.A., Basovizza, Trieste, Italy
| | - Franco Zanini
- Elettra - Sincrotrone Trieste S.C.p.A., Basovizza, Trieste, Italy
| | - Federico Bernardini
- Centro Fermi, Museo Storico della Fisica e Centro di Studi e Ricerche "Enrico Fermi", Piazza del Viminale 1, 00184, Roma, Italy.,Multidisciplinary Laboratory, The "Abdus Salam" International Centre for Theoretical Physics, Strada Costiera 11, 34014, Trieste, Italy
| | - Claudio Tuniz
- Centro Fermi, Museo Storico della Fisica e Centro di Studi e Ricerche "Enrico Fermi", Piazza del Viminale 1, 00184, Roma, Italy.,Multidisciplinary Laboratory, The "Abdus Salam" International Centre for Theoretical Physics, Strada Costiera 11, 34014, Trieste, Italy.,Centre for Archaeological Science, University of Wollongong, Northfields Ave, Wollongong, NSW 2522, Australia
| | - Luca Bondioli
- Servizio di Bioarcheologia, Museo delle Civiltà, Rome, Italy
| |
Collapse
|
32
|
Le Cabec A, Dean MC, Begun DR. Dental development and age at death of the holotype of Anapithecus hernyaki (RUD 9) using synchrotron virtual histology. J Hum Evol 2017. [PMID: 28622928 DOI: 10.1016/j.jhevol.2017.03.007] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
The chronology of dental development and life history of primitive catarrhines provides a crucial comparative framework for understanding the evolution of hominoids and Old World monkeys. Among the extinct groups of catarrhines are the pliopithecoids, with no known descendants. Anapithecus hernyaki is a medium-size stem catarrhine known from Austria, Hungary and Germany around 10 Ma, and represents a terminal lineage of a clade predating the divergence of hominoids and cercopithecoids, probably more than 30 Ma. In a previous study, Anapithecus was characterized as having fast dental development. Here, we used non-destructive propagation phase contrast synchrotron micro-tomography to image several dental microstructural features in the mixed mandibular dentition of RUD 9, the holotype of A. hernyaki. We estimate its age at death to be 1.9 years and describe the pattern, sequence and timing of tooth mineralization. Our results do not support any simplistic correlation between body mass and striae periodicity, since RUD 9 has a 3-day periodicity, which was previously thought unlikely based on body mass estimates in Anapithecus. We demonstrate that the teeth in RUD 9 grew even faster and initiated even earlier in development than suggested previously. Permanent first molars and the canine initiated 49 and 38 days prenatally, respectively. These results contribute to a better understanding of dental development in Anapithecus and may provide a window into the dental development of the last common ancestor of hominoids and cercopithecoids.
Collapse
Affiliation(s)
- Adeline Le Cabec
- Department of Human Evolution, Max Planck Institute for Evolutionary Anthropology, Deutscher Platz 6, D-04103, Leipzig, Germany; Beamline ID19, Structure of Materials, ESRF - The European Synchrotron, 71, avenue des Martyrs, CS 40220, F-38043, Grenoble, Cédex 9, France.
| | - M Christopher Dean
- Department of Cell and Developmental Biology, University College London, Gower Street, London, WC1E 6BT, UK.
| | - David R Begun
- Department of Anthropology, University of Toronto, Toronto, ONT M5S 3G3, Canada.
| |
Collapse
|
33
|
Wang C, Zhao L. Perikymata distribution on anterior teeth of Miocene Lufengpithecus lufengensis from Yunnan, Southern China. AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY 2016; 162:191-196. [PMID: 27670624 DOI: 10.1002/ajpa.23102] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/13/2016] [Revised: 08/11/2016] [Accepted: 09/01/2016] [Indexed: 11/09/2022]
Abstract
OBJECTIVES The present study investigated the distribution of perikymata on anterior teeth of Miocene Lufengpithecus lufengensis so as to broaden the comparative data of developmental variation within and among hominoids. We also compared perikymata-spacing pattern of Lufengpithecus lufengensis with hominins and extant African great apes to understand the implication of dental development. MATERIALS AND METHODS A total of 30 anterior teeth (including 6 I1, 10 I2, and 14 C) of Lufengpithecus lufengensis were examined using a scanning electron microscope and Keyence VHX-600EOS digital microscope to document the number and distribution of perikymata on their labial surfaces. The labial crown height of each tooth was divided into 10 equal deciles and the total perikymata number in each decile was recorded. The mean number of perikymata per millimeter was then calculated for each decile. SPSS statistical software was used to perform analyses of these data, including t-tests for sexual dimorphism and plots showing the perikymata distribution in Lufengpithecus lufengensis. RESULTS Perikymata counts of Lufengpithecus lufengensis in the first three deciles are fewer than the remaining deciles, and with perikymata becoming increasingly more closely packed as growth progresses from cusp to cervix, but decrease in density in the cervical decile. Besides, total labial perikymata counts of canines tend to display very significant sexual dimorphism. DISCUSSION Lufengpithecus lufengensis anterior teeth are more similar in their distribution of labial perikymata to those of Australopithecus than those of other hominins and extant African great apes from previous studies.
Collapse
Affiliation(s)
- Cuibin Wang
- Key Laboratory of Vertebrate Evolution and Human Origins of Chinese Academy of Sciences, Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, Beijing, 100044, China.,University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Lingxia Zhao
- Key Laboratory of Vertebrate Evolution and Human Origins of Chinese Academy of Sciences, Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, Beijing, 100044, China
| |
Collapse
|
34
|
Dean MC. Measures of maturation in early fossil hominins: events at the first transition from australopiths to early Homo. Philos Trans R Soc Lond B Biol Sci 2016; 371:20150234. [PMID: 27298465 PMCID: PMC4920291 DOI: 10.1098/rstb.2015.0234] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/01/2016] [Indexed: 12/18/2022] Open
Abstract
An important question in palaeoanthropology is whether, among the australopiths and the first fossil hominins attributed to early Homo, there was a shift towards a more prolonged period of growth that can be distinguished from that of the living great apes and whether between the end of weaning and the beginning of puberty there was a slow period of growth as there is in modern humans. Evidence for the pace of growth in early fossil hominins comes from preserved tooth microstructure. A record of incremental growth in enamel and dentine persists, which allows us to reconstruct tooth growth and compare key measures of dental maturation with modern humans and living great apes. Despite their diverse diets and way of life, it is currently difficult to identify any clear differences in the timing of dental development among living great apes, australopiths and the earliest hominins attributed to the genus Homo There is, however, limited evidence that some early hominins may have attained a greater proportion of their body mass and stature relatively earlier in the growth period than is typical of modern humans today.This article is part of the themed issue 'Major transitions in human evolution'.
Collapse
Affiliation(s)
- M Christopher Dean
- Department of Cell and Developmental Biology, University College London, Gower Street, London WC1E 6BT, UK
| |
Collapse
|
35
|
Smith TM. Dental development in living and fossil orangutans. J Hum Evol 2016; 94:92-105. [DOI: 10.1016/j.jhevol.2016.02.008] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2015] [Revised: 12/29/2015] [Accepted: 02/25/2016] [Indexed: 10/22/2022]
|
36
|
Kierdorf U, Death C, Hufschmid J, Witzel C, Kierdorf H. Developmental and Post-Eruptive Defects in Molar Enamel of Free-Ranging Eastern Grey Kangaroos (Macropus giganteus) Exposed to High Environmental Levels of Fluoride. PLoS One 2016; 11:e0147427. [PMID: 26895178 PMCID: PMC4760926 DOI: 10.1371/journal.pone.0147427] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2015] [Accepted: 01/04/2016] [Indexed: 11/18/2022] Open
Abstract
Dental fluorosis has recently been diagnosed in wild marsupials inhabiting a high-fluoride area in Victoria, Australia. Information on the histopathology of fluorotic marsupial enamel has thus far not been available. This study analyzed the developmental and post-eruptive defects in fluorotic molar enamel of eastern grey kangaroos (Macropus giganteus) from the same high-fluoride area using light microscopy and backscattered electron imaging in the scanning electron microscope. The fluorotic enamel exhibited a brownish to blackish discolouration due to post-eruptive infiltration of stains from the oral cavity and was less resistant to wear than normally mineralized enamel of kangaroos from low-fluoride areas. Developmental defects of enamel included enamel hypoplasia and a pronounced hypomineralization of the outer (sub-surface) enamel underneath a thin rim of well-mineralized surface enamel. While the hypoplastic defects denote a disturbance of ameloblast function during the secretory stage of amelogenesis, the hypomineralization is attributed to an impairment of enamel maturation. In addition to hypoplastic defects, the fluorotic molars also exhibited numerous post-eruptive enamel defects due to the flaking-off of portions of the outer, hypomineralized enamel layer during mastication. The macroscopic and histopathological lesions in fluorotic enamel of M. giganteus match those previously described for placental mammals. It is therefore concluded that there exist no principal differences in the pathogenic mechanisms of dental fluorosis between marsupial and placental mammals. The regular occurrence of hypomineralized, opaque outer enamel in the teeth of M. giganteus and other macropodids must be considered in the differential diagnosis of dental fluorosis in these species.
Collapse
Affiliation(s)
- Uwe Kierdorf
- Department of Biology, University of Hildesheim, Hildesheim, Germany
- * E-mail:
| | - Clare Death
- Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Werribee, Victoria, Australia
| | - Jasmin Hufschmid
- Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Werribee, Victoria, Australia
| | - Carsten Witzel
- Department of Biology, University of Hildesheim, Hildesheim, Germany
| | - Horst Kierdorf
- Department of Biology, University of Hildesheim, Hildesheim, Germany
| |
Collapse
|
37
|
Hupková A, Šáliová S, Králík M, Malček R. Nejsou čáry jako čáry: inkrementální linie v mikrostruktuře zubů a jejich využití při analýze kosterních nálezů. ACTA ACUST UNITED AC 2016. [DOI: 10.5817/sab2016-2-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
|
38
|
TSUTAYA TAKUMI, MIYAMOTO HIROSHI, UNO HIKARU, OMORI TAKAYUKI, GAKUHARI TAKASHI, INAHARA AKIYOSHI, NAGAOKA TOMOHITO, ABE MIKIKO, YONEDA MINORU. From cradle to grave: multi-isotopic investigations on the life history of a higher-status female from Edo-period Japan. ANTHROPOL SCI 2016. [DOI: 10.1537/ase.161029] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022]
Affiliation(s)
- TAKUMI TSUTAYA
- Graduate School of Science, Kyoto University, Kyoto
- Department of Integrated Biosciences, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa
| | | | - HIKARU UNO
- National Agriculture and Food Research Organization, Institute for Agro-Environmental Sciences, Tsukuba
| | | | - TAKASHI GAKUHARI
- College of Human and Social Sciences, Kanazawa University, Kanazawa
| | | | - TOMOHITO NAGAOKA
- Department of Anatomy, St. Marianna University School of Medicine, Kawasaki
| | - MIKIKO ABE
- Department of Anatomy and Cell Biology, Graduate School of Medicine, Osaka City University, Osaka
| | - MINORU YONEDA
- Department of Integrated Biosciences, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa
- The University Museum, The University of Tokyo, Tokyo
| |
Collapse
|
39
|
Le Cabec A, Tang N, Tafforeau P. Accessing developmental information of fossil hominin teeth using new synchrotron microtomography-based visualization techniques of dental surfaces and interfaces. PLoS One 2015; 10:e0123019. [PMID: 25901602 PMCID: PMC4406681 DOI: 10.1371/journal.pone.0123019] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2014] [Accepted: 02/26/2015] [Indexed: 12/02/2022] Open
Abstract
Quantification of dental long-period growth lines (Retzius lines in enamel and Andresen lines in dentine) and matching of stress patterns (internal accentuated lines and hypoplasias) are used in determining crown formation time and age at death in juvenile fossil hominins. They yield the chronology employed for inferences of life history. Synchrotron virtual histology has been demonstrated as a non-destructive alternative to conventional invasive approaches. Nevertheless, fossil teeth are sometimes poorly preserved or physically inaccessible, preventing observation of the external expression of incremental lines (perikymata and periradicular bands). Here we present a new approach combining synchrotron virtual histology and high quality three-dimensional rendering of dental surfaces and internal interfaces. We illustrate this approach with seventeen permanent fossil hominin teeth. The outer enamel surface and enamel-dentine junction (EDJ) were segmented by capturing the phase contrast fringes at the structural interfaces. Three-dimensional models were rendered with Phong’s algorithm, and a combination of directional colored lights to enhance surface topography and the pattern of subtle variations in tissue density. The process reveals perikymata and linear enamel hypoplasias on the entire crown surface, including unerupted teeth. Using this method, highly detailed stress patterns at the EDJ allow precise matching of teeth within an individual’s dentition when virtual histology is not sufficient. We highlight that taphonomical altered enamel can in particular cases yield artificial subdivisions of perikymata when imaged using X-ray microtomography with insufficient resolution. This may complicate assessments of developmental time, although this can be circumvented by a careful analysis of external and internal structures in parallel. We further present new crown formation times for two unerupted canines from South African Australopiths, which were found to form over a rather surprisingly long time (> 4.5 years). This approach provides tools for maximizing the recovery of developmental information in teeth, especially in the most difficult cases.
Collapse
Affiliation(s)
- Adeline Le Cabec
- ESRF—The European Synchrotron, 71, avenue des Martyrs, CS 40220, F-38043 Grenoble, Cédex 9, France
- Department of Human Evolutionary Biology, Harvard University, Cambridge, MA, 02138, United States of America
- Department of Human Evolution, Max Planck Institute for Evolutionary Anthropology, Deutscher Platz 6, D-04103, Leipzig, Germany
- * E-mail: (PT); (ALC)
| | - Nancy Tang
- Department of Human Evolutionary Biology, Harvard University, Cambridge, MA, 02138, United States of America
- Department of Preventive Medicine, Exposure Biology Laboratory, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America
| | - Paul Tafforeau
- ESRF—The European Synchrotron, 71, avenue des Martyrs, CS 40220, F-38043 Grenoble, Cédex 9, France
- * E-mail: (PT); (ALC)
| |
Collapse
|
40
|
Żądzińska E, Lorkiewicz W, Kurek M, Borowska-Strugińska B. Accentuated lines in the enamel of primary incisors from skeletal remains: A contribution to the explanation of early childhood mortality in a medieval population from Poland. AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY 2015; 157:402-10. [DOI: 10.1002/ajpa.22731] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/27/2014] [Revised: 02/10/2015] [Accepted: 02/13/2015] [Indexed: 01/28/2023]
Affiliation(s)
- Elżbieta Żądzińska
- Department of Anthropology; Faculty of Biology and Environmental Protection, University of Łódź; 90-237 Poland
| | - Wiesław Lorkiewicz
- Department of Anthropology; Faculty of Biology and Environmental Protection, University of Łódź; 90-237 Poland
| | - Marta Kurek
- Department of Anthropology; Faculty of Biology and Environmental Protection, University of Łódź; 90-237 Poland
| | - Beata Borowska-Strugińska
- Department of Anthropology; Faculty of Biology and Environmental Protection, University of Łódź; 90-237 Poland
| |
Collapse
|
41
|
Kierdorf H, Witzel C, Kierdorf U, Skinner MM, Skinner MF. “Missing perikymata”-fact or fiction? A study on chimpanzee (Pan troglodytes verus) canines. AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY 2015; 157:276-83. [DOI: 10.1002/ajpa.22720] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/12/2014] [Revised: 01/11/2015] [Accepted: 02/02/2015] [Indexed: 11/08/2022]
Affiliation(s)
- Horst Kierdorf
- Department of Biology; University of Hildesheim; Hildesheim 31141 Germany
| | - Carsten Witzel
- Department of Biology; University of Hildesheim; Hildesheim 31141 Germany
| | - Uwe Kierdorf
- Department of Biology; University of Hildesheim; Hildesheim 31141 Germany
| | - Matthew M. Skinner
- School of Anthropology and Conservation; University of Kent; Canterbury CT2 7NR UK
- Department of Human Evolution; Max Planck Institute for Evolutionary Anthropology; Leipzig 04103 Germany
| | - Mark F. Skinner
- Department of Archaeology; King's Manor, University of York; York YO1 7EP UK
| |
Collapse
|
42
|
Dental ontogeny in pliocene and early pleistocene hominins. PLoS One 2015; 10:e0118118. [PMID: 25692765 PMCID: PMC4334485 DOI: 10.1371/journal.pone.0118118] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2014] [Accepted: 01/06/2015] [Indexed: 11/19/2022] Open
Abstract
Until recently, our understanding of the evolution of human growth and development derived from studies of fossil juveniles that employed extant populations for both age determination and comparison. This circular approach has led to considerable debate about the human-like and ape-like affinities of fossil hominins. Teeth are invaluable for understanding maturation as age at death can be directly assessed from dental microstructure, and dental development has been shown to correlate with life history across primates broadly. We employ non-destructive synchrotron imaging to characterize incremental development, molar emergence, and age at death in more than 20 Australopithecus anamensis, Australopithecus africanus, Paranthropus robustus and South African early Homo juveniles. Long-period line periodicities range from at least 6–12 days (possibly 5–13 days), and do not support the hypothesis that australopiths have lower mean values than extant or fossil Homo. Crown formation times of australopith and early Homo postcanine teeth fall below or at the low end of extant human values; Paranthropus robustus dentitions have the shortest formation times. Pliocene and early Pleistocene hominins show remarkable variation, and previous reports of age at death that employ a narrow range of estimated long-period line periodicities, cuspal enamel thicknesses, or initiation ages are likely to be in error. New chronological ages for SK 62 and StW 151 are several months younger than previous histological estimates, while Sts 24 is more than one year older. Extant human standards overestimate age at death in hominins predating Homo sapiens, and should not be applied to other fossil taxa. We urge caution when inferring life history as aspects of dental development in Pliocene and early Pleistocene fossils are distinct from modern humans and African apes, and recent work has challenged the predictive power of primate-wide associations between hominoid first molar emergence and certain life history variables.
Collapse
|
43
|
Tsutaya T, Yoneda M. Reconstruction of breastfeeding and weaning practices using stable isotope and trace element analyses: A review. AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY 2014; 156 Suppl 59:2-21. [DOI: 10.1002/ajpa.22657] [Citation(s) in RCA: 138] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/13/2014] [Accepted: 10/17/2014] [Indexed: 01/09/2023]
Affiliation(s)
- Takumi Tsutaya
- Department of Integrated Biosciences; Graduate School of Frontier Sciences, The University of Tokyo; Kashiwanoha 5-1-5 Kashiwa Chiba 277-8562 Japan
| | - Minoru Yoneda
- Department of Integrated Biosciences; Graduate School of Frontier Sciences, The University of Tokyo; Kashiwanoha 5-1-5 Kashiwa Chiba 277-8562 Japan
- The University Museum, The University of Tokyo; Hongo 7-3-1 Bunkyo Tokyo 113-0033 Japan
| |
Collapse
|
44
|
Jordana X, Marín-Moratalla N, Moncunill-Solé B, Köhler M. Ecological and life-history correlates of enamel growth in ruminants (Artiodactyla). Biol J Linn Soc Lond 2014. [DOI: 10.1111/bij.12264] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Affiliation(s)
- Xavier Jordana
- Institut Català de Paleontologia Miquel Crusafont (ICP); Universitat Autònoma de Barcelona; 08193 Bellaterra Barcelona Spain
| | - Nekane Marín-Moratalla
- Institut Català de Paleontologia Miquel Crusafont (ICP); Universitat Autònoma de Barcelona; 08193 Bellaterra Barcelona Spain
| | - Blanca Moncunill-Solé
- Institut Català de Paleontologia Miquel Crusafont (ICP); Universitat Autònoma de Barcelona; 08193 Bellaterra Barcelona Spain
| | - Meike Köhler
- ICREA at Institut Català de Paleontologia Miquel Crusafont (ICP); Universitat Autònoma de Barcelona; 08193 Bellaterra Barcelona Spain
- Departament d'Ecologia; Facultat de Biologia; Universitat de Barcelona; Diagonal 645 E-08028 Barcelona Spain
| |
Collapse
|
45
|
Kierdorf H, Breuer F, Richards A, Kierdorf U. Characterization of Enamel Incremental Markings and Crown Growth Parameters in Minipig Molars. Anat Rec (Hoboken) 2014; 297:1935-49. [DOI: 10.1002/ar.22951] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Revised: 04/09/2014] [Accepted: 04/11/2014] [Indexed: 11/12/2022]
Affiliation(s)
- Horst Kierdorf
- Department of Biology; University of Hildesheim; Germany
| | | | | | - Uwe Kierdorf
- Department of Biology; University of Hildesheim; Germany
| |
Collapse
|
46
|
Mersey B, Brudvik K, Black MT, Defleur A. Neanderthal axial and appendicular remains from Moula-Guercy, Ardèche, France. AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY 2013; 152:530-42. [DOI: 10.1002/ajpa.22388] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2013] [Accepted: 09/19/2013] [Indexed: 11/06/2022]
Affiliation(s)
- Ben Mersey
- Human Evolution Research Center; University of California Berkeley; 3101 Valley Life Sciences Building Berkeley CA 94720-3160
- Department of Integrative Biology; University of California Berkeley; 3040 Valley Life Sciences Building Berkeley CA 94720-3140
| | - Kyle Brudvik
- Human Evolution Research Center; University of California Berkeley; 3101 Valley Life Sciences Building Berkeley CA 94720-3160
- Department of Integrative Biology; University of California Berkeley; 3040 Valley Life Sciences Building Berkeley CA 94720-3140
| | - Michael T. Black
- Phoebe A. Hearst Museum of Anthropology; University of California Berkeley; 103 Kroeber Hall Berkeley CA 94720-3712
| | - Alban Defleur
- CNRS UMR 5276, Laboratoire de Géologie de Lyon, Ecole Normale Supérieur de Lyon, Allée d'Italie, 69364 Lyon Cedex 07, France
| |
Collapse
|
47
|
Affiliation(s)
- Tanya M. Smith
- Department of Human Evolutionary Biology, Harvard University, Cambridge, Massachusetts 02138;
| |
Collapse
|
48
|
Kierdorf H, Kierdorf U, Frölich K, Witzel C. Lines of evidence-incremental markings in molar enamel of Soay sheep as revealed by a fluorochrome labeling and backscattered electron imaging study. PLoS One 2013; 8:e74597. [PMID: 24040293 PMCID: PMC3765360 DOI: 10.1371/journal.pone.0074597] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2013] [Accepted: 08/06/2013] [Indexed: 01/17/2023] Open
Abstract
We studied the structural characteristics and periodicities of regular incremental markings in sheep enamel using fluorochrome injections for vital labeling of forming enamel and backscattered electron imaging in the scanning electron microscope. Microscopic analysis of mandibular first molars revealed the presence of incremental markings with a daily periodicity (laminations) that indicated successive positions of the forming front of interprismatic enamel. In addition to the laminations, incremental markings with a sub-daily periodicity were discernible both in interprismatic enamel and in enamel prisms. Five sub-daily increments were present between two consecutive laminations. Backscattered electron imaging revealed that each sub-daily growth increment consisted of a broader and more highly mineralized band and a narrower and less mineralized band (line). The sub-daily markings in the prisms of sheep enamel morphologically resembled the (daily) prisms cross striations seen in primate enamel. Incremental markings with a supra-daily periodicity were not observed in sheep enamel. Based on the periodicity of the incremental markings, maximum mean daily apposition rates of 17.0 µm in buccal enamel and of 13.4 µm in lingual enamel were recorded. Enamel extension rates were also high, with maximum means of 180 µm/day and 217 µm/day in upper crown areas of buccal and lingual enamel, respectively. Values in more cervical crown portions were markedly lower. Our results are in accordance with previous findings in other ungulate species. Using the incremental markings present in primate enamel as a reference could result in a misinterpretation of the incremental markings in ungulate enamel. Thus, the sub-daily growth increments in the prisms of ungulate enamel might be mistaken as prism cross striations with a daily periodicity, and the laminations misidentified as striae of Retzius with a supra-daily periodicity. This would lead to a considerable overestimation of crown formation times in ungulate teeth.
Collapse
Affiliation(s)
- Horst Kierdorf
- Department of Biology, University of Hildesheim, Hildesheim, Germany
| | - Uwe Kierdorf
- Department of Biology, University of Hildesheim, Hildesheim, Germany
| | - Kai Frölich
- Department of Biology, University of Hildesheim, Hildesheim, Germany
- Tierpark Arche Warder e.V., Warder, Germany
| | - Carsten Witzel
- Department of Biology, University of Hildesheim, Hildesheim, Germany
| |
Collapse
|
49
|
Abstract
PURPOSE OF REVIEW Accurate prenatal exposure assessment is one of the major challenges in environmental epidemiologic studies. Variations in placental transport make maternal biospecimens unreliable for many chemicals and fetal specimens collected at birth do not provide information on exposure timing over the prenatal period. RECENT FINDINGS The skeletal compartment is an important chemical repository, making calcified tissues important for measuring exposure. For decades teeth have been used to estimate long-term cumulative exposure to metals and some organic chemicals. Recently developed methodologies that combine sophisticated histological and chemical analysis to precisely sample tooth layers that correspond to specific life stages have the potential to reconstruct exposure in the second and third trimesters of prenatal development and during early childhood. SUMMARY Such a retrospective biomarker that precisely measures exposure intensity and timing during prenatal development would substantially aid epidemiologic investigations, particularly case-control studies of rare health outcomes.
Collapse
|
50
|
Sešelj M. Relationship between dental development and skeletal growth in modern humans and its implications for interpreting ontogeny in fossil hominins. AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY 2012; 150:38-47. [PMID: 23283663 DOI: 10.1002/ajpa.22209] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/07/2012] [Revised: 11/14/2012] [Accepted: 11/14/2012] [Indexed: 11/12/2022]
Affiliation(s)
- Maja Sešelj
- Department of Anthropology, New York University, NY 10003, USA.
| |
Collapse
|