I know this is difficult for most of you to understand. Let's try these
bulleted points:
- Y chromosome mutations occur at the birth of men along a male lineages
on the average of one about every 150 years, roughly once every five
generations.
- Although we don't know the name of these ancestors, we can roughly tag
every fifth or sixth ancestor in the lineage with the name of a SNP. In
other words, SNP L448 was born with a specific individual in the
neighborhood of 3200 years ago (according to yfull.com).
- The Y chromosome is passed whole hog from father to son, right along
with any mutations, generation after generation.
In this way, all mutations in a lineage accumulate over the thousands and
hundreds of thousands of years. That's why Don and I both have the YP355
SNP (which came after L448) and the newly discovered YP4248, which the
Hackett tester also has. Because we know the average rate of mutations, we
can date the Cooley/Hackett split to about 1250AD.
I've updated my table:
http://ancestraldata.com/staging/cooley-hackett-SNP.html
Remember, the pink box include the SNPs that only Don and Hackett shared.
*Well, I now share them too.) In time, we'll find other testers (and
surnames) who share them. After all, the string terminated in the 13th
century.
Don had six SNPs with whom he matched no one. Now, he and I match on 3 or
4 of them. Since we have a match, the SNP masters (who ever they are) will
give them names and designate one of them as being representative of the
block.
This new block of SNPs began to emerge after the YP4248 block was fully
formed. In other words, those three or four SNPs were acquired by our
Cooley ancestors between c1250 and John Cooley's birth c1740, over a
period of about 500 years. That works: 3 SNPs times 150 years is 450
years.
So, three or so of our Cooley ancestors who lived between 1250 and 1740
had mutations at birth. We don't know their names, but we know something
about their DNA.
Additionally, I have two SNPs not matched with Don. These would have had
to come down through the line from Edward (John's son) to me. I doubt
another descendant of Edward's will ever do the Big Y. They will,
therefore, remain without names.
Don now has one (perhaps two) personal SNPs that would have been
introduced somewhere in the line from John's son James to himself.
Finally, if anyone is interested, I've created a custom SNP test at
yseq.net for YP4248. It's $17.50. Once a name is established for our John
Cooley SNP, I'll create a test for that also. (Remember, we don't know at
what point the mutation occurred. It could have been John's 3rd
great-grandfather, for example. Someone who tests positive for it will
still have an unknown relationship to John. It genetic terms, though, it
will be pretty darn close.
I always welcome questions.
-Michael
- Administrator or Co-Administrator for the following family DNA projects:
Akins, Ashenhurst, Bishop, Eldridge, Fisk, alt-McDowell, Cooley,
McDougall, Pickens, Strother - B.A. Humboldt State University, History,
2013 - Instructor, the Osher Lifelong Learning Institute (OLLI) at HSU
Received on Tue Aug 25 2015 - 02:32:11 CDT