If there is a Manly female ancestor who wasn't married and had a male child with the surname of Manly would the DNA trace stop with this son ? I understood that the DNA had to trace back on the male line. This would have been in the 1780's. I was thinking of having my uncle, who is over 90 years, run a DNA, but if it only goes back a few generations then it might not be worth the cost. He decends from Gray & Manly.