The Phillips DNA Project News

The Science of Your Direct Paternal Line

The Y chromosome is a sex chromosome. Sex chromosomes carry the genetic code that makes each of us male or female. All people inherit two sex chromosomes. One comes from their mother and the other from their father. Men receive a Y chromosome from their father and an X chromosome from their mother. Men and only men inherit their father’s Y chromosome. Thus, it follows the same path of inheritance as their direct paternal line.

Paternal line DNA testing uses STR markers. STR markers are places where your genetic code has a variable number of repeated parts. STR marker values change slowly from one generation to the next. Testing multiple markers gives distinctive result sets. These sets form signatures for a paternal lineage. We compare your set of results to those of other men in our database. The range of possible generations before you share a common ancestor with a match depends on the level of test you take. A match may be recent, but it may also be hundreds of years in the past.