Jean-François Tournepiche

How Neanderthal molar teeth grew

Growth and development are both fundamental components of demographic structure and life history strategy. Together with information about developmental timing they ultimately contribute to a better understanding of Neanderthal extinction. Primate molar tooth development tracks the pace of life history evolution most closely, and tooth histology reveals a record of birth as well as the timing of crown and root growth. High-resolution micro-computed tomography now allows us to image complex structures and uncover subtle differences in adult tooth morphology that are determined early in embryonic development. Here we show that the timing of molar crown and root completion in Neanderthals matches those known for modern humans but that a more complex enamel–dentine junction morphology and a late peak in root extension rate sets them apart. Previous predictions about Neanderthal growth, based only on anterior tooth surfaces, were necessarily speculative. These data are the first on internal molar microstructure; they firmly place key Neanderthal life history variables within those known for modern humans.

Suggested guidelines for invasive sampling of hominid remains

The last few years have witnessed remarkable technical developments in paleoanthropology. On the one hand, accurate imaging techniques have limited the need to access actual specimens. On the other hand, direct dating, isotopic studies, and the study of ancient DNA, proteins, and microstructures have experienced great technical improvements but still require a degree of invasive sampling. The power of these invasive approaches for answering important questions in evolutionary anthropology brings forward the question of how to balance preservation of fossil hominid remains for the future against the application of current scientific analyses. In order to address these issues, a workshop was hosted by the Max-Planck Institute for Evolutionary Anthropology in Leipzig on April 26– 27, 2007 where the issues that emanate from the need for sampling of hominid remains versus the need for preservation of specimens for the future were discussed. At the end of the meeting, the participants produced a set of recommendations that might be useful to museums and other institutions as well as scientists that have to make decisions on requests for invasive sampling of hominid remains.