SHANGHAI, Jan. 17 (Xinhua) -- An international research team has discovered that an ancient nomadic group, which migrated from China to Eastern Europe, had preserved almost a reproductive barrier between it and the local indigenous population for about two centuries, even though they did share a common culture.

After first being dispelled by Turkic people roaming the Mongol plateau and then embarking on a long-distance migration, the Avars, who had Eastern Asian origins, reached what is now Hungary between 567 and 568 CE. There, they encountered local groups with distinctly different European genetic backgrounds.

Researchers from China, Germany, Austria, Hungary and the United States analyzed ancient genetic data from 722 individuals, along with a comparative study of two neighboring cemeteries dating back to the 7th and 8th centuries, respectively, located south of Vienna in Austria.

They reconstructed six-generation pedigrees at both sites, including up to 450 closely related individuals, and found that even 200 years after migration, the ancestry at the Leobersdorf site had remained dominantly East Asian-like, whereas the M?dling site revealed local, European-like ancestry.

However, they did share a distinctive late-Avar culture, according to the study published this week in the journal Nature.

The generations-long genetic barrier was maintained by systematically choosing partners with similar ancestry from other sites in the Avar realm, researchers said.

Also, the few genetic flows between these two sites were mostly due to female exogamy -- a practice where women marry outside their own social group, tribe or community, according to the study.

The study further revealed that how the Avars had settled in Europe, and assimilated locals while forming large patrilineal clans during that period.

Wang Ke, from Fudan University in Shanghai, is the paper's first author and co-corresponding author. ■