The data, published by Classic Biology, reveal a genetic barrier between the Finns and the rest of Europe. This is not surprising because the relatively small Finnish population for generations lived nomadic lives almost isolated from the rest of Europe.

A second genetic barrier separates Italy from the other countries, which may reflect the role of the Alps in impeding free flow of people between Italy and the rest of Europe.

A mirror of migration patterns

The researchers found that the genetic map closely resembled the pattern of three major human migrations mainly from the south. Southern Europeans revealed more genetic diversity than Scandinavians, British and Irish, mirroring the migration waves of early humans from Africa about 35,000 years ago, post-ice age expansion 20,000 years ago and the population movements driven by farming methods emanating from the Middle East about 10,000 years ago.

According to John Novembre, a US scientist who led one of the studies, the data "tells us that geography matters."

Genetic differences can be traced to the birthplaces of Europeans. The map depicts a Spanish-Portuguese cluster to the southwest below that of France. The Italians are further southeast, while the Danish, Dutch, French and German clusters are centrally positioned.

The researchers are confident that they can soon pinpoint to a few hundred kilometres the ancestry of individual Europeans.

Such data can be useful for forensic medicine but also for anyone in the US, Australia or Canada wishing to trace their European ancestry.