Methodology, Sources and resources

How can you incorporate DNA evidence into your family tree?

You have had your DNA tested. You have analysed the results and reached some conclusions. Now you have to decide what changes you need to make to your family tree.

I am not going to talk about how to reach a conclusion using DNA evidence. That topic has been covered extensively elsewhere. What I want to discuss is how you can take the information and evidence obtained from autosomal DNA testing and apply it to your family tree.

What can DNA tell us?

DNA testing provides evidence about biological relationships between people who have been tested. From that information you draw conclusions about the identity of your ancestors.

This can be very useful for your family tree, because it might:

  • support what you have learned from documentary sources
  • refute what you have learned from documentary sources, or
  • fill gaps in your family tree.

What might you add to your tree?

A DNA source citation:

If your analysis of DNA matches supports your conclusion about the identity of someone who is already in your family tree, you might add a DNA source citation to their profile to document that the evidence has been strengthened. This is sometimes referred to as ‘confirming’ a relationship.

Example source citation from Wikitree for DNA evidence of a paternal relationship, where the father was the son of Samuel Bassett and Mary Doolan
Source citation from Wikitree setting out the DNA evidence for the father of my great grandmother

An identified person or group of people:

If you are able to gather sufficient evidence to support a conclusion about how a DNA match is related to you, you could add that match to your tree. If the ancestral line of that match is not already in your tree, you could also add that line to document how they are related to you via your most recent common ancestor (MRCA).

An unidentified person or group of people:

If your DNA match has supplied a family tree, you can add them to your tree even if you do not yet have sufficient evidence to determine how they related to you. In this case you add the match as an unlinked person and use their tree to investigate your relationship. Adding a group of related matches and combining their trees is often a useful strategy. More on this point below, under ‘Confirmed or hypothetical’.

Extract from an Ancestry family tree showing Bernard Lyons, wife Elizabeth Flanagan and Elizabeth's brother Francis Flanagan.
A large group of DNA matches suggested that I was related to Elizabeth Flanagan. I had her in my family tree for over a year before I worked out how we were related.

Extra documentation:

If your analysis confirms how a DNA match is related to you and they have extra information about family members, you might add that information to your family tree. This could include photos, events that they participated in or other details of their lives.

DNA source citations should be included in all of these circumstances.

What might you alter or remove from your tree?

Remove a person or family line:

If DNA provides evidence that you have the wrong people in your family tree, you may have to delete a person or family line. If you are uncomfortable with deleting them entirely, you could just unlink them and leave them in your tree.

Alter a relationship:

If DNA provides evidence that you have the right people in your tree but that the relationships are incorrect you will need to alter the relationships. This usually involves unlinking and reconnecting to establish the correct relationship.

If DNA provides evidence that a biological relationship is incorrect but they are still part of the family in some way, you might like to keep them in your tree but change how they are related to you. For example, if DNA demonstrates that someone was adopted you could add the biological line, keep the non-biological line and record the adoptive parents as such.

Extract from an Ancestry family tree showing biological parents and adopted parents
My father has two sets of parents

What do you need to document?

The mechanics of deleting, unlinking and changing relationships in your family tree will vary depending on where you store your tree. Just remember to back up your tree before you make any changes, in case you want to revert to the old tree at some point.

Source citations:

Source citations are essential. Here are a few useful articles on this topic:

Statement of evidence: 

Sometimes a source citation is not enough and you may need to include a statement that documents the evidence you used to reach a conclusion (often referred to as proof statements and proof arguments). You could include these as notes on the person’s profile or attach a separate document as media.

Extract from Ancestry family tree describing the evidence for a child of Catherine Flanagan and Alan Everett
Evidence statement on an Ancestry family tree

Identifying DNA matches: 

Identifying or labelling your DNA matches in your family tree helps with future analysis, especially if you have not yet gathered sufficient evidence to confirm the relationship. The most common methods are to use profile images, tags or hashtags. You can also identify members of a cluster or group in this way.

Ancestry allows you to add the tag ‘DNA match’ to people in your tree
Data sheet for an individual from Legacy family tree software showing the hashtag symbol and a DNA event or fact
Two options for identifying DNA matches in Legacy family tree – hashtag and an Event/Fact

Identifying MRCA:  

It can also be helpful to identify the most recent common ancestors (MRCA) of a group of DNA matches and add information about whether or not their relationship to you has been confirmed.

Ancestry allows you to add tags and you can also add a DNA confirmed image as the profile picture

Identifying the line between a DNA match and MRCA:

Marking the people in a direct line between a DNA match and your most recent common ancestor can also assist your research. In the image above, Ancestry allows you to add a tag ‘DNA Connection’ to indicate that ‘This person is a relative on the path between a DNA Match and a common ancestor.’ A DNA connection image can also be added to online family trees or your family history software.

Blue and purple DNA symbol
Example icon that can be added to the profile pictures of the ancestral lines of a DNA match

Confirmed or hypothetical: 

If your research method involves adding people to your family tree before you have confirmed that they belong there, then you should have a means of distinguishing between the confirmed people and the unconfirmed people. Some may shudder at this approach, but it is one that I myself use at times because I find that having them in my tree makes them easier to research.

An example of this situation might be where you add the family tree of a DNA match, mark them as unconfirmed, and then set out to verify their tree with further research. An alternative to this approach is to create separate family trees for unconfirmed matches.

Other information: 

You might like to store other information about DNA matches on your tree, to make the information more accessible. If your family tree is online, be careful you do not share any information about matches which violates their privacy.

You could record information such as email address, the name and URL of their online family tree, their location and their ethnicity as an Event/Fact on the profile of your DNA matches in your family history software.

Your own ethnicity predictions: 

Your ethnicity predictions could be stored on your own profile in your family tree as an attached document (media) or as an Event/Fact.

Research questions or plans: 

DNA test results will generate research questions and hypotheses to be tested. If they relate to a specific DNA match or MRCA, you could keep them handy by recording them on the relevant profile in your tree.

Privacy issues

Privacy is a complex issue when documenting DNA evidence. If you are interested in exploring this issue, I would recommend The Legal Genealogist blog.

Further information

My articles:

DNA Sydney website

2 thoughts on “How can you incorporate DNA evidence into your family tree?”

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