The people tested are living descendants of the ancestors. The Y-chromosome DNA makes few mutations when passed from male to male each generation. The 12 marker test tells you whether you match genealogy DNA with another individual and therefore that person's entire male-to-male ancestry back to a common ancestor. The 25 marker test is significantly more accurate than the 12 marker test and provides a better estimate of how far back two people share a common ancestor. Larry Jordan Charlotte, NC Visit my genealogy website at: http://jordannctoal.homestead.com/DNAindex.html Subj: Re: [JORDAN] DNA confusion?? Date: 9/9/2002 7:45:22 PM Eastern Daylight Time From: <A HREF="mailto:Mudder9651">Mudder9651</A> To: <A HREF="mailto:LJordan316">LJordan316</A> How can there be a DNA match with anyone that far back. Do you have their DNA to match with?