How was the database used to estimate the ancestry of each user constructed? 

Our database consists of modern populations, reflecting the current genetic diversity of different human populations. To be part of our database and registered as belonging to an ethnicity, an individual and their family must be natives of that genetic population for at least the last three generations.

Additionally, each individual undergoes a quality control to determine if they can be part of the reference population used. By following these strict quality criteria, our team continuously works to increase the populations included in our test, as well as the accuracy in their assignment.