Y-Chromosome DNA
(To view an Adobe flash player presentation from SMGF, click on the double helix above)
The Y-Chromosome is one of the chromosomes that determines gender and is only present in males. Because each man has only one Y-Chromosome, there is no recombination with other Chromosomes. Instead the Y-Chromosome is passed down directly and nearly unchanged from father to son.
Because it is passed down only from father to son, Y-DNA is only informative about a small fraction of your ancestors. Just those in the direct paternal line. However, since Y-Chromosome DNA does accumulate changes very slowly, it is a rich source of information going back many generations. It is important to note that even though a woman does not have her own Y-Chromosome, analysis of a Y-Chromosome of a relative such as her father, uncle or brother can reveal information about her paternal lineage.
Information and chart are from the "Sorenson Molecular Genealogy Foundation"
 copy.PNG)
All males connected by blue lines have common Y-DNA