Thursday, June 2, 2016

More adventures with AncestryDNA NADs - NADs Up/NADs Down - Update

This is starting to get real old, real quick. I understand that science moves forward and as we continue to research things will change. Lord only knows I have lived through three versions of AncestryDNA updates and a couple at FTDNA. But Ancestry should be ashamed of this NADs fiasco. To unleash the barrage of NADs on the heels of the v3 update without truly testing how the v3 would effect those NADs is nothing short of irresponsible.

How can I say that you ask?

I am one of those lucky folks to have tested both parents so in theory I should benefit from Ancestry phasing our autoomal DNA test. I'm not uncomfortable at this point with the v3 update although I still have high confidence false positives.

But those NADs I was hanging around five NADs before the update. When the NAD update hit that number jumped to 17. But the rub was only nine of them were shared by my parents. Eight of them were false postives. I immediately sent a support message to Ancestry. and now the big update again, I'm down to seven and my parents have all those NADs.

So here is the fallout of the bouncing NADs - pre v3 update - v3 update - current: 

My test                    5-17-7
My father              10-35-8
My mother              4-14-5
My wife                17-28-15
Wife's 2nd cousin 18-33-18
My 2nd cousin        9-14-4

My original article on the false NADs posted on my family blog at

Let's hope this is the last update for awhile at Ancestry, but I fear we have at least one more coming (that is the rumor I am hearing).

Come on folks I need a chance to catch up my documentation and I am tired of adding columns to my spreadsheet documenting your ups and downs. Please give this a rest for a while.

Here is Ancestry's response to my Facebook post on their FB page:

"Hi Larry, we apologize for any frustration you may have experienced with the New Ancestor Discoveries. In order to determine New Ancestor Discoveries, we created an algorithm with criteria that connects people to DNA Circles based on their DNA matches. This algorithm was created last year when we launched New Ancestor Discoveries and with the rapid growth of the DNA database, we are finding it needs to be updated.

"As DNA Circles get larger and more DNA matches are delivered, more people are connecting into the DNA Circles, which results in more New Ancestor Discoveries, but with a decrease in accuracy. So, we are updating the criteria to make it more conservative and increase the accuracy of New Ancestor Discoveries. This means you’ll need more connections into a DNA Circle to get a New Ancestor Discovery.

"These updates will result in a significant decrease in the number New Ancestor Discoveries, but with an increase in accuracy. We will continue to monitor and adjust this as necessary to ensure these provide meaningful discoveries for our members."

And then there is this explanation from Anna Swayne of Ancestry DNA:

"Previously, you needed to match at least 2 members of a known DNA Circle to be given a New Ancestor Discovery. Now, users must match at least 3 members of a small (15 members or less) DNA Circle to be given a New Ancestor Discovery. For larger DNA Circles (16+ members), users must match 20% of that Circle to be given a New Ancestor Discovery. For example, if there is a DNA Circle of 10 people, you will need to match at least 3 people to get a New Ancestor Discovery. And if there is a DNA Circle of 30 people you will now need to match 6 people instead of 2."