890 research outputs found

    Dental Development As A Measure Of Life History In Primates

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    Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/137591/1/evo04266.pd

    Mortality and magnitude of the "wild effect" in chimpanzee tooth emergence

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    Age of tooth emergence is a useful measure of the pace of life for primate species, both living and extinct. A recent study combining wild chimpanzees of the Taï Forest, Gombe, and Bossou by Zihlman et al. (2004) suggested that wild chimpanzees erupt teeth much later than captives, bringing into question both comparisons within the hominin fossil record and assessment of chimpanzees. Here, we assess the magnitude of the “wild effect” (the mean difference between captive and wild samples expressed in standard deviation units) in these chimpanzees. Tooth emergence in these wild individuals is late,although at a more moderate level than previously recorded, with a mean delay conservatively estimated at about 1 SD compared to the captive distributions. The effect rises to 1.3 SD if we relax criteria for age estimates. We estimate that the mandibular M1 of these wild chimpanzees emerges at about 3 2/3-3 3/4 years of age. An important point, often ignored, is that these chimpanzees are largely dead of natural causes, merging the effect of living wild with the effect of early death. Evidence of mortality selection includes, specifically: younger deaths appear to have been more delayed than the older in tooth emergence, more often showed evidence of disease or debilitation, and revealed a higher occurrence of dental anomalies. Notably, delay in tooth emergence for live-captured wild baboons appears lower in magnitude (ca. 0.5 SD) and differs in pattern. Definitive ages of tooth emergence times in living wild chimpanzees must be established from the study of living animals. The fossil record, of course, consists of many dead juveniles; the present study has implications for how we evaluate them. 2010 Elsevier Ltd. All rights reserved.Max Planck Institute of Evolutionary Anthropology, GermanyPeer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/87989/1/Smith Boesch 2010 final.pd

    Chapter 11. Evolution of the Human Life Cycle

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/134403/1/Bogin & Smith_2000_Evolution of the Human Life Cycle rd.pdfDescription of Bogin & Smith_2000_Evolution of the Human Life Cycle rd.pdf : Book chapter pd

    Don’t throw the baby teeth out with the bathwater: Estimating subadult age using tooth wear in commingled archaeological assemblages

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    Commingled assemblages of fragmentary human skeletal remains are a common feature of many archaeological sites and pose significant analytical problems for bioarchaeologists. Such deposits often contain a high volume of the teeth of subadults for which it is challenging to estimate age, including developing permanent teeth with damaged roots, articulated teeth with roots obscured by alveolar bone, and deciduous teeth with completed root apices.Here, we present a new method for more precisely estimating age for the developmentally ambiguous teeth of subadults from archaeological contexts. We used a sample of articulated subadult dentition from the Copper Age site of Marroquíes in Jaén, Spain, to build linear models of the relationship between dental age and tooth wear for deciduous and permanent molars. We tested three different strategies for identifying and removing outliers to build a linear model with the strongest relationship between age and wear. The Adjusted Residual strategy, which used diagnostic plots of linear regression residuals in the statistical package R to identify and remove outliers, was found to produce the strongest linear model. The linear model developed using the Adjusted Residual strategy was then used to provide estimated midpoint ages and upper and lower age bounds based on the wear scores from the sample of developmentally ambiguous teeth.This study demonstrates that it is possible to estimate the age of developmentally ambiguous deciduous and permanent molars with reference to an adequate sample of subadult dentition with estimated ages from the same population. This new method is valuable as it extracts information from developmentally ambiguous teeth that would otherwise be inaccessible, allows for rapid data collection, employs standard macroscopic dental scoring methods, and can be used for sites from other regions and periods. We conclude by discussing the applications of this new method within bioarchaeology and identify directions for future research on subadult dental wear.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/151955/1/oa2802_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/151955/2/oa2802.pd

    Premolar Development And Eruption In The Early Eocene Adapoids Cantius Ralstoni And Cantius Abditus (Mammalia, Primates)

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    http://deepblue.lib.umich.edu/bitstream/2027.42/78461/1/Contributions_32_no_03_12-22-10.pd

    Eruption Sequence Similarities in the Maxilla and Mandible

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/68195/2/10.1177_00220345800590092501.pd

    Developmental Communalities in Tooth Emergence Timing

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/67014/2/10.1177_00220345800590072501.pd

    A Mandibular-maxillary Precedence Field in Tooth Eruption

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/68078/2/10.1177_00220345800590091801.pd

    "Schultz's Rule" and the evolution of tooth emergence and replacement patterns in primates and ungulates

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    Edited by Mark F. Teaford, Moya Meredith Smith and Mark W.J. FergusonPeer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/106593/1/Smith 2000 SchultzsRule.pd

    Life history and the evolution of human maturation

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    The Taung child, like fossils of other individuals who died before reaching adulthood, is a piece of the puzzle of the evolution of human growth and development, the puzzle of when, how, and why human “life history” evolved into its modern form. With regard to Taung, interest focuses on both its rate of growth (maturation of the child in relation to its age) and its pattern of growth (synchrony of the elements of maturation). The meaning of rates and patterns of growth, as well as the interpretation of maturation of Taung or any other fossil mammal, are best understood through the broad perspectives provided by comparative study of mammalian life history and the techniques of allometry.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/38585/1/1360010406_ftp.pd
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