Amino acid dating accuracy

21-Oct-2017 15:55

Here we describe a method to date hydroxyproline found in collagen (~10% of collagen carbon) as a bone-specific biomarker that removes impurities, thereby improving dating accuracy and confidence. The burial lies under cultural layer III, but no signs of a burial pit were observed from the level of this cultural layer. The pit containing the body had cut through the volcanic ash horizon at the site, the Campanian Ignibrite (CI), which was clearly visible in the walls but absent from the burial fill (22, 23).

This method is applied to two important sites in Russia and allows us to report the earliest direct ages for the presence of anatomically modern humans on the Russian Plain. The most probable context for the burial is thought to be with the “cultural layer in volcanic ash” of Aurignacian attribution (between cultural layers III and IVa). The stratigraphic context and direct radiocarbon dates of material from the same cultural level therefore suggest that the age of the human must be at least 30 ka BP.

S1), is one of only three fossil human remains with a “complete” published mt DNA sequence (17) and it shows the five diagnostic substitutions defining haplogroup U2, present also in modern populations in Europe.

The Kostenki 14 (Markina Gora) human skeleton excavated near Voronezh, Russia (Fig.

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These inaccuracies in turn frustrate the development of archaeological chronologies and, in the Paleolithic, blur the dating of such key events as the dispersal of anatomically modern humans. The resulting 1.2 mg graphite, produced for dating by accelerator mass spectrometry (AMS), yielded an age of 33,250 ± 500 y BP (There is independent evidence for the age of the burial, based on the excavated sequence at Kostenki. Rogachev (21, 22), the excavator, rejected any possibility for the burial to be attributed to cultural layer III, which is dated to ∼28.3–31.7 ka BP (19).

These are bones that previously have proved impossible to reliably date due, it is thought, to the effects of museum conservation or to site-based organic contaminants.

We have applied the technique to a set of important anatomically modern human bones from the Early and Mid-Upper Paleolithic of Russia.

Methods to quantitatively assess the quality of AAR data and to identify aberrant specimens are under-developed.

Here we examine a variety of screening criteria for identifying outliers and determining the suitability of specimens for numerical dating including: high serine concentrations (modern contamination), covariance of aspartic acid (Asp) and glutamic acid (Glu) concentrations (diagenetic influences), replication of measurements (specimen heterogeneity), and the relation between Asp and Glu d/l values (internal consistency).

These inaccuracies in turn frustrate the development of archaeological chronologies and, in the Paleolithic, blur the dating of such key events as the dispersal of anatomically modern humans. The resulting 1.2 mg graphite, produced for dating by accelerator mass spectrometry (AMS), yielded an age of 33,250 ± 500 y BP (There is independent evidence for the age of the burial, based on the excavated sequence at Kostenki. Rogachev (21, 22), the excavator, rejected any possibility for the burial to be attributed to cultural layer III, which is dated to ∼28.3–31.7 ka BP (19).

These are bones that previously have proved impossible to reliably date due, it is thought, to the effects of museum conservation or to site-based organic contaminants.

We have applied the technique to a set of important anatomically modern human bones from the Early and Mid-Upper Paleolithic of Russia.

Methods to quantitatively assess the quality of AAR data and to identify aberrant specimens are under-developed.

Here we examine a variety of screening criteria for identifying outliers and determining the suitability of specimens for numerical dating including: high serine concentrations (modern contamination), covariance of aspartic acid (Asp) and glutamic acid (Glu) concentrations (diagenetic influences), replication of measurements (specimen heterogeneity), and the relation between Asp and Glu d/l values (internal consistency).

AB - Amino acid racemization (AAR) is a cost-effective method for dating the large numbers of specimens required for time-averaging studies.