A two-step match in a 37 marker YDNA test is not very close. The
common ancestor probably lived ten or more generations ago. So
don't assume that the Y and autosomal (FF) matches came >from the
same ancestor. Intermarriage of distant cousins was quite common,
particularly in the little shtetls of eastern Europe, where
everyone knew one another and the choice of spouses was limited.
For most of us with Ashkenazi ancestry the paper trail disappears
in the early 1800s, and most of the Y-DNA matches pre-date that
time. So the chance of correlating a DNA match with your documented
family tree is small.
From: Elaine Bush <erbush@...>
Date: Wed, 16 Oct 2013 14:20:43 -0700
I have FF results for myself and for my maternal first cousin. Is it
safe to say that if there is a match on my FF list who does not turn
up anywhere on his FF list, that that match comes >from my paternal
side? It would seem so, but one of my results odd: My maternal
male cousin has a yDNA match 37 markers, 2 steps. This Y match match
turns up on my FF results as 4th to remote, however does not turn up
at all on my cousin's FF results.
The yDNA is different >from my brother's, and so I guess this elusive
FF match could be >from my paternal grandmother's side?