New method of determining geographic origin of humans
Leiden researchers have developed a new method of determining the geographic origin of humans. Archaeologist Jason Laffoon and his team used the technique to discover where precolonial pioneers in the Caribbean region came from.
When we research human migration in the past, it is a challenge to pinpoint where exactly different individuals or groups came from. DNA studies are widely used methods for research on human remains, but in terms of geographic origins, these genetic studies provide more information about the ancestors of the individual found, according to Dr Laffoon. ‘The DNA cannot tell us about an individual's personal origin, where he or she spent their childhood,' he explains.
Isotope research is increasingly being used to determine the origin of archaeological (or forensic) remains. Based on radioactive isotopes in the human remains, it is possible to distinguish between locals and immigrants. 'Although we can trace which individuals are immigrants in the area, we still don't know where they came from.'
Laffoon and his team combined isotope research with GIS (Geographic Information Systems) and statistical analyses to develop a new method that makes it possible to determine where the individual originally came from. Laffoon: ‘We can combine this with biochemical analysis of human remains, such as teeth, so that we are able to determine the geographic origin of individuals.'
The team tested this new method on the tooth of a modern person of known origin - from Caracas, Venezuela - and the results showed a very good match with this location. The team then tested the model on two archaeological teeth from different sites in the Caribbean, of which the origin was suspected. While less precise than with the modern tooth, the results of these tests also indicated specific regions as the places of origin.
Archaeology and forensic research
The new method earned Laffoon's team a publication in the scientific journal PLOS ONE. The team is now working on further validating the method. 'The technique has the potential to strongly improve the precision and accuracy with which the origins can be determined,' says Laffoon. 'This could have very important implications not only for archaeological studies of migrations but also for forensic research into, for example, the identification of human remains in crime investigations.'