Europe's Romani people, widely known as gypsies, migrated out of northwestern India about 1,500 years ago, researchers say.
The Romani represent the largest minority group in Europe, consisting of approximately 11 million people, but lack written historical records on their origins.
"We were interested in exploring the population history of European Romani because they constitute an important fraction of the European population, but their marginalized situation in many countries also seems to have affected their visibility in scientific studies," says David Comas of the Institut de Biologia Evolutiva at Universitat Pompeu Fabra in Spain.
The team gathered genome-wide data from 13 Romani groups across Europe. This pinned down their geographic origin to north or northwestern India, and gave a date of origin of about 1,500 years ago.
But while the Middle East and Caucasus regions are known to have had an important influence on the Romani language, the researchers saw limited evidence for shared genetic ancestry between the European Romani and those who live in those regions of the world today.
Once in Europe, Romani people began settling in various locations, likely spreading across Europe via the Balkan region about 900 years ago.
"From a genome-wide perspective, Romani people share a common and unique history that consists of two elements: the roots in northwestern India and the admixture with non-Romani Europeans accumulating with different magnitudes during the out-of-India migration across Europe," says Manfred Kayser from Erasmus University Rotterdam.
"Our study clearly illustrates that understanding the Romani's genetic legacy is necessary to complete the genetic characterization of Europeans as a whole, with implications for various fields, from human evolution to the health sciences."