GENEALOGY-DNA-L ArchivesArchiver > GENEALOGY-DNA > 2002-12 > 1040643077
From: "Gary Rea" <>
Subject: Re: [DNA] Counting ancestors, measuring ancestry
Date: Mon, 23 Dec 2002 05:31:17 -0600
While I haven't read the book you mentioned, I have read a similar book,
some years ago, that said that our primary genetic inheritance is from our
parents, and that the amount of genetic material inherited from previous
generations diminishes as you go back in time. In fact, the author said that
we inherit virtually no genetic material at all by the time you get back to
your great-grandparents. I don't know if this view still squares with what
is now known, though. We do know now that the "Y" chromosome is passed,
virtually unchanged, down through each male generation for many generations,
undergoing mutations once in a few centuries. Is this what you're talking
----- Original Message -----
From: "Jerry Smith" <>
Sent: Monday, December 23, 2002 11:47 AM
Subject: [DNA] Counting ancestors, measuring ancestry
> Some years back I recall a book (perhaps "Heredity and You"?) that said it
> was possible to *not* be genetically related to a grand-parent and that by
> the sixth generation back, it was around a 50/50 chance that there was a
> genetic connection with any one ancestor.
> It also said that most genetic material was passed along via whole
> chromosomes but there was some 'cross-over' (don't remember what that was)
> Is this consistent with current thinking?
> If so, might not such a 'loss' of ancestors account for at least some of
> the discrepancy between our family knowledge of heritage and that measured
> by DNA testing (except, of course, the 'edge' --Y and Mt-- tests)?
> Given that there is a fairly small number of genes (or whatever the
> smallest bit of genetic information that can be passed along is), is it
> reasonable to have a greater count for 'ancestors'?
> Jerry Smith
> in Sacramento, CA
> trying to make some sense of it all...
|Re: [DNA] Counting ancestors, measuring ancestry by "Gary Rea" <>|