The science of osteo-archaeology

How scientists analyse human bones to discover 'we are what we eat'.

How scientists analyse human bones to discover 'we are what we eat'.

Isotopic analysis: Carried out on human teeth enamel and bone collagen. Plants can be divided into three groups - two of land plants and one of marine plants - based on their differing rations of ¹³C and ¹²C. As plants are eaten by animals these rations are passed along the food chain, eventually to be fixed in human and animal bone collagen. The ratios can show whether diet was based on land or marine plants, i.e. we are what we eat.

Strontium analysis: The Sr isotope measured in bone and teeth can be used to infer the geographic region that an animal or human inhabited, because different regions tend to have distinct Sr isotope compositions. The Sr isotope composition measured in human teeth will reflect the average Sr isotope composition that was ingested as a child, due to the stable nature of Sr and Ca in teeth after formation, whereas the Sr isotope composition of bone will reflect the average isotopic composition over the last 10 years of life, due to continuous biological processing of Sr and Ca in bone.

Radiocarbon dating: US chemist Willard Libbey published the first radiocarbon dates in 1949. Radiocarbon 14C is produced in the atmosphere and absorbed by plants through carbon dioxide and is passed along the food chain. Uptake of 14C ceases at death and decays at a known rate. Libbey discovered that the age of the dead plant or animal could be calculated by measuring the amount of radiocarbon left in a sample. Traces of 14C are reduced by half after 5,730 years.

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The Department of Archaeology and Palaeoecology at Queen's University in Belfast offers a MSc/Diploma in Environmental Archaeology, while UCC offers an MA in Archaeology which includes a module in Human Osteo-archaeology.