Many of the other autosomal dna forums are talking about big upcoming changes here on how ancestry.com autosomal dna match lists will be presented in the future. Because for various reasons, most “advanced” discussions of autosomal dna issues are no longer posted on these dna message boards here at ancestry.com, I thought I would try to bring posters here up-to-date on what appears to be about to happen to your ancestry.com dna match list.

For some time, ancestry.com folks have been hinting at changes in their methodology and a few days ago they shared information on their plans with a number of genetic genealogical dna bloggers and provided more details on the changes expected by the end of the year. Don’t expect any information from ancestry to its customers until it happens (maybe a week later) as over the past two years, changes have generally happened without prior notice (and in the early days, i.e. two years ago, people who regularly posted here would share information on changes they had observed before they were officially announced.).

One of the bloggers posted a summary a day or so ago. Google “The Legal Genealogist” by Judy G. Russell to get a nice summary. (Url links are sometimes not allowed here so just google it to locate the detailed information.)

The bottom line is that ancestry is going to drastically reduce the number of matches you have by eliminating matches that fall into certain heavy population areas…sometimes called hotspots where it appears that the autosomal dna shows up in large numbers of people and may reflect common ancestors beyond what we normally think of as within the genealogical framework. If you use gedmatch or genome mate to play with chromosome matching data (i.e. people with ancestry.com autosomal dna have either uploaded to gedmatch or tested at another company that has a chrome browser tool which ancestry doesn’t have) you will see the places where many, many of your matches line up with small pieces of dna.

The discussions in other forums are generally favorable to getting rid of matches that aren’t genealogically useful, although there are some views that they would rather have all the information even if it includes false positives (due to these hotspots) or they have been able to pinpoint common ancestors even in these hot spots.

Another concern is that if ancestry eliminates thousands of matches, will your match list be overpopulated with private or no tree testers, who aren’t helpful on genetic genealogy anyway?

My initial thought is that if you use the Snavely chrome extension to download your ancestry.com dna matches to your laptop or desktop, it is a good idea to do that now to capture everyone you have…then you can later reexamine that list if they disappear here. I use only the summary tool (not the ancestors because that data base would be too large for me ). It appears that any notes you added on people who disappear will likely disappear as well (i.e. when they are not longer on your match list, anything you wrote will likely disappear, so if you kept notes on connections you were thinking about, they will be gone unless you screen shot or used the chrome extension to capture them.)

This change will reinforce the importance of transferring ancestry.com autosomal dna to either FTDNA or gedmatch where you can examine your matches in detail and find people who ancestry.com doesn't list on your match list (i.e. like FTDNA matches who fail to pass their 20 cms test, but are real matches).