A study published in the journal Nature by a team of 31 researchers from the U.S. and Europe details how the four-year-old’s skeletal remains — excavated at the Mal’ta archeological site in south-central Siberia in the 1920s and kept since then at Russia’s Hermitage State Museum — yielded a DNA signature shared by modern European populations but also by many present-day aboriginal people in the Western Hemisphere.

The ancient boy’s DNA profile may help explain why a “European” strain of genetic material can be found among today’s New World indigenous communities, a mystery that many scientists had assumed was the result of contact in recent centuries with successive waves of colonizers from Europe.

Another controversial theory to explain the shared DNA is based on the idea that boat-using tribes of seal-hunters from ancient Europe might have migrated westward to the Americas along a North Atlantic ice edge.