DNA from the boy buried 12,600 years ago shows his people were ancestors of many of today's native peoples.
Another aftershock rocked Japan today, one month to the day since the devastating earthquake and tsunami killed more than 10,000 and left more than 100,000 homeless.
Many of those people are still living in evacuation centers set up in schools and temples. In some places the wreckage is being cleared, but the job will take years. The BBC’s correspondent Roland Buerk reports from Kamaishi on the northeast coast.