Coca chewing in prehistoric coastal Peru: dental evidence.

In this study, we describe the dental health of four prehistoric human populations from the southern coast of Peru, an area in which independent archaeological evidence suggests that the practice of coca-leaf chewing was relatively common. A repeated pattern of cervical-root caries accompanying root exposure was found on the buccal surfaces of the posterior dentition, coinciding with the typical placement of coca quids during mastication. To further examine the association between caries patterning and coca chewing, caries site characteristics of molar teeth were utilized as indicators for estimating the likelihood of coca chewing for adults within each of the study samples. Likelihood estimates were then compared with results of a test for coca use derived from hair samples from the same individuals. The hair and dental studies exhibited an 85.7% agreement. Thus, we have demonstrated the validity of a hard-tissue technique for identifying the presence of habitual coca-leaf chewing in ancient human remains, which is useful in archaeological contexts where hair is not preserved. These data can be used to explore the distribution of coca chewing in prehistoric times. Simultaneously, we document the dental health associated with this traditional Andean cultural practice.

Identification of Mycobacterium tuberculosis DNA in a pre-Columbian Peruvian mummy.

The existence of tuberculosis in the pre-Columbian Americas is controversial because the morphology of the lesion is not specific, the organism is culturally nonviable in ancient tissues, and nonpathogenic soil mycobacteria can contaminate buried bodies. We report the recovery of DNA unique to Mycobacterium tuberculosis from a lung lesion of a spontaneously mummified, 1000-year-old adult female body in southern Peru. This provides the most specific evidence possible for the pre-Columbian presence of human tuberculosis in the New World.

Cocaine and metabolites in the hair of ancient Peruvian coca leaf chewers.

Cocaine and its metabolites, benzoylecgonine (BZE) and ecgonine methylester (EME), were found in hair samples from ancient Peruvian coca-leaf chewers dating back to AD 1000. Hair was analyzed by gas chromatography/mass spectrometry (GC/MS) to quantitate the concentrations. The two metabolites were found in higher concentration than the parent drug. The metabolite levels appear to be below that of modern cocaine abusers. Gender does not appear to be a factor in the incorporation of drug into hair.

Genetic correlations between sides and heritability of asymmetry for nonmetric traits in rhesus macaques on Cayo Santiago.

The use of nonmetric traits for estimation of biological distance is a long-standing practice in biological anthropology. Nonmetric traits can be scored using either the individual or the side of the individual as the unit of measure. If sides of the individual are genetically correlated the use of sides would produce redundant genetic information. For this reason, Korey (Am. J. Phys. Anthropol. 53:19-23, 1980) argues for the use of individuals as the unit of measure for nonmetric traits. Ossenberg (Am. J. Phys, Anthropol. 54:471-479, 1981), however, argues that bilateral occurrence of nonmetric traits indicates greater genetic liability for the trait and that therefore the sides are the more biologically correct unit of measure. Genetic correlations for 13 cranial nonmetric traits are estimated for a sample of rhesus macaque skeletons from Cayo Santiago. In addition, heritability of asymmetry is estimated for these 13 traits as a test of Ossenberg's contention that asymmetry is genetically influenced. Significant genetic correlations between sides support Korey's contention that nonmetric traits should be scored by individual. Only two asymmetry heritabilities were significantly different from zero, providing no significant support for Ossenberg's contention that asymmetry is genetically determined. Our results support the theory that asymmetry represents a measure of the ability of an organism to buffer stresses. Therefore, a measure of the heritability of asymmetry is a measure of the heritability of the ability to buffer stresses. This ability does not appear to be heritable in this sample.