[Teeth as time capsules: isotope research].

Teeth and molars are of extraordinary value to archaeology and forensic science. They are small time capsules that, through isotope analysis, reveal their secrets about where people come from, what path they followed during childhood, and what kind of food they ate. Because teeth are so resistant to physical degradation and diagenesis, even millennia-old dental elements can still provide information about human populations. Isotope analysis is also used in forensic science to obtain information about the origins of unidentified individuals, in order to push an investigation in a (new) direction. Isotope research is based on the premise 'you are what you eat'; the isotope ratios of the food consumed are reflected in the tooth enamel. If the isotopic composition of the tooth enamel is compared with the expected composition of the geologic substrate, insight can be gained into the origin of an individual.