“Go Fish!” 7 Tips for Casting a Wide DNA Net

When seeking to identify a biological relationship, don't overlook the importance of casting a wide DNA net. We'll show you how!

*names have been changes to protect privacy

What Does “Casting a Wide DNA Net” Mean?

Over the last decade, DNA testing has proven to be a powerful tool in genealogy research. One of the strategies repeated most often is the recommendation to “cast a wide net”, or test at all the major testing companies. This is also commonly referred to as “fishing in all ponds.” The idea is to include your DNA at all the major databases in hopes of finding matches through any or all of them, as you never know which company your key match is going to test at. It sounds good in theory, but how effective is it really for solving genealogical problems? A recent client’s story highlights what can happen when multiple databases are used together to solve a genetic genealogy mystery. 

If At First You Don't Succeed, Try, Try Again…

Reuben* was born in the southern United States, and was placed for adoption at birth. As he grew interested in learning about where his biological ancestors were from, he purchased DNA tests at 23andMe and AncestryDNA, and once he received his results, he came to Legacy Tree Genealogists for help in identifying those ancestors. We reviewed his matches at those sites, and while he had some close matches, we ran into the typical problems—missing or private trees, unresponsive matches, and a lack of clear connections between close matches. As a result of these obstacles, we helped him transfer his data to FamilyTreeDNA. 

Once his results were ready at FamilyTreeDNA, we checked his match list and were shocked to see his closest match was his biological mother! Not only that, another close match turned out to be her son, a maternal half-brother of Reuben’s, who did have a tree. This same brother had tested at AncestryDNA, but his tree at that site was private, while the tree at FamilyTreeDNA was public and viewable. Many users who test at multiple companies will, for various reasons, attach a tree to one site and not the others, or make one tree public and keep the others private. Testing at multiple companies allows you to look for those close matches and possibly find the one site where they include their tree for all to see. Reuben’s half-brother’s tree allowed us to quickly identify which of his matches were maternal and which were paternal, and soon we had his birth mother’s tree researched back four generations to their roots in Sicily. 

The closest two matches on Reuben’s FamilyTreeDNA match list.

Overcoming Misattributed Parentage With Cluster Research

The situation for Reuben’s birth father did not come together so easily. Contacting his mother and other maternal relatives produced no information. He had several close paternal matches, but their trees did not line up—no one had any surnames or ancestors in common. It seemed likely some of those close matches may have included misattributed parentage, whether because of adoptions or inaccuracies. We were able to find connections between some of Reuben’s more distant paternal matches at AncestryDNA that allowed us to identify several groups of interrelated matches (called clusters). Identifying common ancestors between your matches can be a very effective strategy, as it can help you identify potential common ancestors between you and your matches. However, tracing forward the descendants of common ancestral couples to find candidates can be time intensive. 

After several weeks of research, we had a breakthrough. A new close paternal match appeared at 23andMe, and a linked family tree included all the ancestors of those clusters we had identified. Using her tree, we were able to identify Reuben’s biological father’s family. 

Reuben’s new paternal match in his 23andMe match list. 

Finding Answers Through DNA Can Take Time and Patience

Startling discoveries of close relatives at one database happens many times in our research. The testing companies’ databases are continually growing as new people test or transfer their data. Going back to your match list every few months, especially in the months following a major holiday like Christmas or Mother’s Day, when tests are often purchased as gifts for family members, can lead to a new batch of matches to sort through and analyze. 

In the end, no one database was enough to identify Reuben’s biological ancestors. Each database held a piece of the puzzle, and it was only by combining the data from each database that we were able to assemble Reuben’s biological family tree. Utilizing all the genetic genealogy tools at your disposal—casting a wide DNA net and testing with multiple testing companies, using third-party tools like GEDmatch, hiring professional genetic genealogists, and a healthy dose of patience—can help you bust through almost any brick wall. 

Tips for Casting a Wide DNA Net

1. Test the oldest living generation, closest to your genealogical problem, first. Members of older generations in your family are closer to your ancestors and will thus have more of their DNA in their genome. They will have the closest matches on that side of your family. This can be a grandparent, parent, aunt or uncle, great-aunt or great-uncle, or even a parent’s first cousin. 
2. AncestryDNA and 23andMe will only process tests performed with them, and do not accept uploads from other companies. Begin with one or both of these tests. 
3. MyHeritage DNA and FamilyTreeDNA do accept uploads from other sites (including Ancestry DNAand 23andMe) and have good size databases and some great tools to work with, though some features are locked until a small fee is paid. Note: If you choose to upload your data to these sites, you will need to agree to their terms of service. Be sure you’re comfortable with these terms before proceeding. Once the data is uploaded, it takes a few days to a week before the results are available. 
4. GEDmatch accepts data from all DNA testing platforms, and allows users to upload their data for free and compare their results with everyone who has uploaded to the site. They also have a powerful suite of unique tools that can be used in analyzing your DNA results for a monthly subscription of $10. Once you’ve uploaded your data here, it takes 24 to 48 hours before the results are available. Note: Be sure to review the terms of service, as this database is commonly used by law enforcement in solving criminal cases, however; you must opt-in in order to allow law enforcement to review your results. If you decide to opt-in you have the option to opt out at any time.
5. There are European DNA companies like LivingDNA and Geneanet who also accept uploads from all the major testing companies. As of this writing, the testing databases are relatively small for both companies and may not be immediately helpful, but will likely become more useful as they grow. 
6. Keep track of the matches you know and communicate with. Most of the websites have various tools like messaging systems, notepads, color coding, adding stars, etc. to mark significant matches, makes notes, and correspond with them. You can also find other ways to track your matches, such as a Word or Excel document, Evernote notebooks. Whatever system you choose, once you identify your connection to a match, make sure you keep track of that information. 
7. Review your match lists at all testing companies regularly. Even though the rate of new testers has slowed somewhat compared to a few years ago, new people are continually added to all testing companies’ databases. Keeping track of the matches you’ve worked with already will help you readily identify new matches. 

If you need help determing your relationship to a genetic match, or would like help extending your family lines, let Legacy Tree Genealogists provide the research and the extensions to your family tree. Contact us today for a free quote.