Michael Cooley's Genetic Genealogy Blog GEN • GEN
28 September 2016

Yseq SNP Results for Cooley Group CF04

Yseq has further evaluated and named the SNPs discovered in the recent Big Y test results. Some SNPs are found in locations on the Y chromosome that are deemed unreliable. For example, there are areas that so closely resemble the X chromosome that it can't be certain that they weren't read off the X. Others were found in large areas of STRs, which are subject to regular change, and thus considered not viable for testing. They're still noted, at least for a while, as it's possible that further testing will reveal evidence supporting their inclusion. Yfull and FTDNA have yet to look at them. Once done, there could be further changes. The new graphic indicates those SNPs by graying them out. The graphic in the original article, #25, is likewise updated.

If these interpretations hold out that means the Cooley / Davis MRCA may not have lived as long ago as presently surmised. The Cooley lineage has seven viable private SNPs, the Davis line has six. If we take the average, 6.5, and multiply that with the grossly estimated average mutation rate of once every 144 years, the MRCA lived about 933 years ago, or about the year 1100 AD, perhaps in the time of the Norman Conquest. This brings us closer to the genealogical timeframe and the emergence of surnames.

The better we break up this block, the more accurate will be the timeline. The more we test, the more accurate we can determine the relationship between all CF04 testers.

As always, I'm available for any questions.