Help me understand DNA testing

[Alan H]

This leaves an extremely large part of your ancestry about which neither NRY nor mtDNA can tell you anything at all. If we go back to the great great grandparents level (of which there would have been 16 in total), NRY and mtDNA tests would tell you about just 2 of them, i.e. your father’s father’s father’s father and your mother’s mother’s mother’s mother. This leaves 14 great great grandparents unaccounted for (genetically speaking).

An excellent point and absolutely correct, thanks for mentioning it.