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Sampling and Pretreatment of Tooth Enamel Carbonate for Stable Carbon and Oxygen Isotope Analysis
Published on: August 15, 2018
Variation in enamel thickness within the genus Homo.
Tanya M Smith1, Anthony J Olejniczak, John P Zermeno
1Department of Human Evolutionary Biology, Harvard University, Cambridge, MA 02138, USA. tsmith@fas.harvard.edu
Journal of Human Evolution
|February 25, 2012
Summary
Hominin molar enamel thickness varies significantly across species and time, challenging the notion of a universally "thick enamel" trait. This dental variation impacts our understanding of hominin evolution and paleodemographics.
Area of Science:
- Paleoanthropology
- Dental Anthropology
- Evolutionary Biology
Background:
- Thick molar enamel is a key trait distinguishing hominins from apes.
- Enamel thickness in early Homo and its variability remain poorly understood.
- Previous studies suggest significant intra- and inter-specific variation in later Homo enamel thickness.
Purpose of the Study:
- To investigate taxonomic, geographic, and temporal trends in hominin enamel thickness.
- To analyze enamel thickness variation in fossil Homo teeth spanning two million years.
- To assess the utility of enamel thickness as a taxonomic marker within the genus Homo.
Main Methods:
- Micro-computed tomographic imaging was applied to 150 fossil Homo teeth.
- Average enamel thickness (AET) and relative enamel thickness (RET) were measured.
- Data were analyzed for taxonomic, geographic, and temporal patterns.
Main Results:
- Early Homo teeth from Africa and Asia exhibited highly variable AET and RET.
- Some South African Homo molars showed hyperthick enamel, similar to Paranthropus.
- Later Homo groups generally possessed thick enamel, while Neanderthals displayed relatively thin enamel.
- Recent Homo sapiens have relatively thicker enamel due to disproportionate dentine reduction during dental size decrease.
Conclusions:
- Generalizations of hominins having 'thick enamel' oversimplify a complex and variable trait.
- Enamel thickness variation has limited taxonomic utility within the genus Homo.
- Consideration of this variation is crucial for accurate paleodemographic reconstructions and dietary ecology studies.
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