Ancestry's new DNA by Grandparent

 Ancestry is now offering an ethnicity breakdown, not just by Parent, but by Grandparent.

This has not yet been rolled out to all tests.For some it will say "Coming Soon."

Here, for example, is my mother, and maternal grandparents.

Ancestry is unable to determine which grandparent is which, but it is easy for me to determine by the ethnicity regions. I believe my mother would be shocked if Grandparent 2 actually had any Ashkenazi Jewish ancestry. Those marginal percentages are almost definitely what is often called, 'noise.'  As one friend of mine once put it -- what's less than 1%? 0. [I am also suspicious that there is a possibility their science in dividing the ethnicities by grandparent isn't 100% perfect, and those marginal percentages are just assigned to the wrong grandparent.]

More importantly, it appears that I received an almost equal amount of DNA from both grandparents. Ignoring all of the less than 1%s, Grandparent 1 provided 23%, Grandparent 2 provided 22%. 

Ancestry provides a note that they were unable to assign 7% of my DNA to a grandparent. The remaining 5% is part of that

This is not what always happens. 

As we can see below, my paternal grandparents' DNA are not close to being equal in my genetic makeup.

Since the ethnicity regions are identical, just in different amounts, it's impossible to tell which one is which. But it's a comparison of 12% and 36% with 2% unassigned. A significant difference.

From the number of cousin matches I have been able to identify on each branch, I have a suspicion I know which one is the larger, but I don't believe there is a way to actually confirm it.

But if anyone believed they always received close to 25% of their DNA from each grandparent -- this dispels that belief, and illustrates how over several generations, one branch of your DNA can disappear more quickly than another.