Direct evidence of milk consumption from ancient human dental calculus

Abstract

Milk is a major food of global economic importance, and its consumption is regarded as a classic example of gene-culture evolution. Humans have exploited animal milk as a food resource for at least 8500 years, but the origins, spread, and scale of dairying remain poorly understood. Indirect lines of evidence, such as lipid isotopic ratios of pottery residues, faunal mortality profiles, and lactase persistence allele frequencies, provide a partial picture of this process; however, in order to understand how, where, and when humans consumed milk products, it is necessary to link evidence of consumption directly to individuals and their dairy livestock. Here we report the first direct evidence of milk consumption, the whey protein β-lactoglobulin (BLG), preserved in human dental calculus from the Bronze Age (ca. 3000 BCE) to the present day. Using protein tandem mass spectrometry, we demonstrate that BLG is a species-specific biomarker of dairy consumption, and we identify individuals consuming cattle, sheep, and goat milk products in the archaeological record. We then apply this method to human dental calculus from Greenland's medieval Norse colonies, and report a decline of this biomarker leading up to the abandonment of the Norse Greenland colonies in the 15th century CE.

The Evolutionary Origin and Genetic Makeup of Domestic Horses

“…Combined with current efforts of the FAANG consortium , such approaches promise to reveal the true extent of past individual plasticity and how patterns of gene regulation were modified in response to new domestication/selection targets. Additionally, the recent discovery that dental calculus represents a fantastic source of ancient microbial DNA (Adler et al 2013) and genetic traces of major components of the diet (Warinner et al 2014), encourages the genetic investigation of dietary changes and modification of the oral microbiota that accompanied horse domestication. We anticipate that, together with ancient genome and epigenome reconstruction, these approaches will reveal the true extent of biological transformation that forged the modern horse.…”

Isotopic anthropology of rural German medieval diet: intra- and inter-population variability

“…Additionally, host ancient DNA investigation of 18 individuals in the Dalheim cemetery, on one hand, revealed a high level of genetic lactase persistence, indicative of milk consumption and genetic selection for the trait at some point in the population's past (Krüttli et al, 2014). On the other hand, protein analysis of the dental calculus of nine Dalheim individuals did not identify any milk proteins (Warinner et al 2014b). …”

Successful enrichment and recovery of whole mitochondrial genomes from ancient human dental calculus

“…The biological content of dental calculus is primarily microbial in origin (Warinner et al 2014b), and its parent material, dental plaque, is estimated to contain >200,000,000 microbial cells per milligram (Socransky and Haffajee 2005). In addition to microbes (bacteria and archaea), dental calculus also contains trace amounts of dietary (plant and animal) biomolecules and microfossils, viral DNA (primarily bacteriophages, or bacteria-infecting viruses), and human DNA and proteins (Warinner et al 2014a; Warinner et al 2014b). …”