This is an algorithm and it is called GPS, or rather Geographic Population Structure. It converts genetic information into geographical coordinates in order to reveal the place of origin of individuals in the same way that a "normal" GPS converts satellite system radio waves into geographical coordinates. The genomic GPS presented in the latest issue of the magazine Nature Communications was developed by an international consortium of researchers including Dr. Sergio Tofanelli from the Department of Biology at the University of Pisa.
As the article points out, the algorithm has been tested on around 1,650 individuals belonging to more than 40 different populations. 83% of the individuals were correctly assigned to their place of origin and for some populations, as was the case for Sardinia, they were correctly placed within 50km of their village of origin. It goes without saying that the accuracy of the genomic GPS with respect to a certain population or region depends on the wealth of specific data available and on the absence of recent phenomena of racial mixing or migration. Therefore, it is more accurate if applied to regions such as Sardinia, which have a "historical residency" of the population and a large amount of genomic data.
"The data the genomic GPS elaborates," explains Sergio Tofanelli, "are tens of thousands of variants for each single nucleotide, those with the greatest amount of biogeographical information, which we selected from the millions of different sites of our genome. In technical language they are known as AIMs, that is ancestry informative markers. In particular, my contribution was that of participating in the selection and validation of the specific AIMs of the male transmission genome."
"One of the most innovative aspects of the GPS algorithm," concludes Sergio Tofanelli, "is the application of a new paradigm in human evolutionary genetics which leads to the ultimate withdrawal of any biological implication of the historical concept of race: all the current populations are the fruit of racial mixing."