The iceman cometh: Ötzi's fully defrosted body should yield high-quality samples for analysis. Credit: JOSEF PERNTER/SÜDTIROLER ARCHÄOLOGIEMUSEUM, BOZEN

Six European research groups are eagerly awaiting new samples from the bones, teeth and intestine of Ötzi, the Stone Age man whose body was defrosted last week.

Ötzi's frozen body, over 5,000 years old, was found in 1991 in the Italian Alps close to the Austrian border. It was examined by local researchers for several years before being moved to a specially built museum of archaeology in Bolzano in Italy — under armed guard in case of attacks by Austrian nationalists (see Nature 391, 318 ; 1998).

Since then, tempers have cooled and a more coordinated approach has been established. A scientific committee set up in 1998 comprises researchers from Austria, Switzerland and Italy, and is chaired by Horst Seidler, co-director of the Institute of Anthropology at the University of Vienna.

Six projects have been selected for study. Scientists are particularly interested in analysing Ötzi's genetic make-up, if this proves technically possible. They hope to address medical, pathological and anthropological questions by examining bacterial DNA in his gut flora, to study genetic similarities with modern Europeans, and to learn about migration patterns and diseases in the late Neolithic period.

Previous examinations included isolation and analysis of mitochondrial DNA from tissue samples. But as only the surface of Ötzi's body was warmed up, data from many samples were of low quality. Samples from the completely defrosted body should be more reliable and more readily comparable with other preserved human bodies.

In one of the projects, Franco Rollo, a professor of anthropology at the University of Camerino in Italy, plans to obtain bacterial genetic sequences from the iceman's intestine. Rollo hopes to determine Ötzi's eating habits and the distribution of pathogenic bacteria at the time he was alive.

Another research group, headed by Mark Thomas of the Centre for Genetic Anthropology at University College London, plans to investigate European migration patterns by comparing the iceman's Y-chromosome with genetic dispositions found among contemporary populations.

Another question concerns Ötzi's geographical origins. Wolfgang Müller, a researcher at the Institute for Isotope Geology at the Technical University of Switzerland in Zürich, hopes that the proportion of strontium and lead isotopes in Ötzi's tooth enamel will help provide the answer. If the quality of the enamel samples is high enough, Müller also wants to look into the oxygen isotopes they contain. This could help to determine the temperature conditions during Ötzi's early youth, he says.