Test Parents and Family Members Of course, because you do share roughly half of the same DNA inherited from your parents, you will have some matches to both you and a sibling that are identical by chance in exactly the same way.
The best way to eliminate identical by chance matching, of course, is to test your parents. The next best way to determine legitimate matches is to test other family members.
At Family Tree DNA, they provide customers with the ability to link the DNA tests of family members to their proper location in your tree, and then Family Tree DNA utilizes the common DNA segments to determine common matching between you, that family member(s), and other people.
Those people who match you and a family member on the same segment are then identified as either paternal or maternal matches, based on their position in your tree.
Identifying Lineage When thinking about who to test, half-siblings, if you have any are, a wonderful way to differentiate between maternal and paternal matches.
50% the Same – 50% Different Siblings share approximately 50% of the same DNA of the parents.