Thanks to Alex Williamson for his work on the world tree, and thanks to our three members who are pioneers on the frontier of genetics by taking the Big Y test to find their place on Alex's Big Tree. Through their efforts, the Gleason Lineage 1 group is now known to be located far downstream of SNP DF27 in our own unique block (R-6650231-C-T). Finding this characteristic SNP block is analogous to finding our stem (or twig) on the genetic tree. Those closest to us, on nearby stems of the branch, have roots in England, Scotland, and Ireland.
|Lineage I members on Alex Williamson's Big Tree|
The 7-digit number identifying the block indicates the position on the Y-chromosome where there is an anomaly (mutation) not found among others in the general population. The C-T designation says that the base chemical "C", which is usually found in that location, has morphed into a "T" in our family. You might say that this block of mutations, which are unique to us, define our temporary characteristic or terminal SNP. But as more people test, it may not be unique to our family, and we may need to look further downstream to locate our uniqueness.
Another fascinating discovery is that two of the three subjects share an additional SNP downstream from the block discussed above, at position 22117264-C-T. This can be seen on that portion of the Big Tree that Lineage 1 occupies: http://www.ytree.net/DisplayTree.php?blockID=1368&star=false. By moving right to left and clicking one of the “parent” SNPs at the top of this page, you can expand the tree to see more and more upstream branches.
|Current SNP progression for Lineage I|
Keep in mind that each member has mutation locations that are his alone (so far). It is the shared mutations that are shown in the blocks, and these are not found (as yet) in others. If more members of our lineage were to take the Big Y test, it might be possible to identify the sub-lineages among the family by their shared SNPs.
Judith Gleason Claassen