Deep ancestry is the tracking of family history from as far back as hundreds or even thousands of years. Unlike genetic genealogy of close relatives, a process that usually involves historical records, deep ancestry is using DNA to trace the migration paths of ancestors who traveled the world. Deep ancestry takes advantage of the ability to trace maternal and paternal lines.
One-half of the genetic ancestry test is through mtDNA. This type of DNA is passed from a mother to her biological children. Using an extensive mtDNA database, people of any sex can connect with their maternal relatives and follow the migration paths of their female ancestors.
The other half of the deep genetic ancestry test is the Y-DNA test. Only biological males can take advantage of this test as Y-DNA is found on the Y chromosome and is only passed from father to son. Similar to the mtDNA test, you can compare your DNA to an extensive Y DNA database to connect with male relatives and trace your paternal migration pattern.
Because their tests are only designed to sequence about 0.02% of the full genome, ancestry at companies like 23 and Me are usually limited to ethnicity estimates and information other family members input. Generally, they only analyze specific single nucleotide polymorphisms (SNPs) relevant to most of the population. Deep ancestry performed with whole genome sequencing provides much more insight.
Whole genome sequencing, by sequencing all 20,000 genes, mitochondrial DNA, and the Y chromosome, allows you to discover ancestry information spanning up to thousands of years, using your whole genome as a comparison against potential ancestors in the database. Each sequence is read at least 30 times, ensuring the accuracy of your DNA test results. Access to the raw DNA data produced by whole genome sequencing gives you the power to continuously discover new insights.