AncestryDNA is changing the rules it uses to find people who are related to one another. As Judy Russell writes:

… some of the people who are showing up as matches at AncestryDNA right now will stop showing up as matches. Not huge numbers (not like the last time AncestryDNA revised its system and some folks lost as many as 90% of their matches) — but some. At the same time, some people who now don’t show up as matches may appear in the match list. So in terms of sheer numbers of matches, there isn’t going to be any big change.

Both Judy Russell and Roberta Estes recommend copying your current list of matches. This seems like an odd thing to do since Ancestry claims they will be eliminating incorrect matches. But it’s up to you. Their posts are “Ancestry DNA Alert” and “Upcoming Ancestry DNA Update — Urgent!!!“. To me, these posts sound a bit hysterical. Art Petty writes:

“Circles” and “Newly Discovered Ancestors (NADs)” have always been posted on Ancestry as “Beta Tests.”  It is not surprising to me that as they gain experience and knowledge, the algorithms will be tweaked from time to time to improve reliability.  As the [Estes] article indicates, for most, it is only the most distant (4th to 8th cousins) matches that will be affected anyway.  Typically, for cousins this distant, unless you already have some idea of who the people are, it’s hard to incorporate into your tree anyway.

Thanks to Art & Teri for letting us know about this.