You can use DNA to validate and extend your tree, and you don't need a detailed scientific understanding of DNA to do it. Your DNA match information is much more useful than the ethnicity estimates that disappoint some people, and it can be quite gratifying to find evidence that the family tree you have created is accurate. On this page I've tried to list resources that might be useful for people who want to get started analyzing their own DNA results.
Most of this page is intended to help those who have taken DNA tests and are trying to understand them. For those who have not yet tested, WikiTree provides advice on types of tests and testing companies at Help:DNA Tests.
Questions and suggestions welcome.
WikiTree and DNA
Unlike other genealogy websites, WikiTree allows users to display their DNA test information on their ancestors' profiles for several generations back, and provides a process with specific criteria for documenting DNA Confirmation.
What this does: It enables WikiTreers who share common ancestors to find each other, to learn whether descendants of their ancestors have tested, and to understand the DNA evidence behind connections found on the common family tree. See Help:DNA Features for more information.
What this doesn't do: It does not prove that you match someone, even if you are both listed on the same ancestor's profile. You have to investigate each match for yourself. Even if you do share DNA with someone listed on your ancestor's profile, that alone does not prove that the DNA is from that ancestor. (Are your trees well documented? Are the other people that match you both consistent with the identified family line? Is the match strength reasonable for the identified relationship?)
How to enter your information: You do not upload actual DNA data to WikiTree. You simply state what tests you have taken. To do that, go to your own profile. Click on the "DNA tested" link on the left side of the gray area near the top of your profile. Scroll down to "Add New Test Information" and select from the drop-down menu. Save when you're done.
WikiTree will connect your autosomal test information to all your blood relatives out to eight degrees of separation—up to sixth great grandparents and out to third cousins. Y-DNA and mtDNA information will be connected to all relatives who might share the DNA with you. DNA information is updated once a day, so you will need to wait a day after posting your test information before it shows up on your ancestors' and relatives' profiles. (Obviously, for this to work, your ancestors and relatives must have profiles on WikiTree, and you must be connected to your family.)
DNA Confirmation. WikiTree policy requires that when relationships are marked as "Confirmed with DNA," DNA confirmation statements must be added to the profiles. See Help:Confirmed with DNA and Help:Triangulation among other WikiTree Help pages.
Using your DNA results
Identifying your matches
- Once you get your test results, you will need to identify your matches in order to make use of the information. Some you may already know, such as first cousins, but those are the exceptions. Identifying your matches generally depends on your having traced your family tree back at least a few generations (those seeking to identify unknown parents are a special case). The Blaine Bettinger blog post listed just below has many good tips for identifying matches.
- In early 2019, Ancestry introduced its ThruLines, which illustrate possible relationships between DNA matches descended from common ancestors up to fifth great grandparents. These can be helpful in identifying matches, and suggesting common ancestors, but their accuracy depends on the accuracy of user trees*. Make sure you've verified the paper trail before relying on ThruLine information. (See Randy Seaver's May 3, 2021 blog post, listed in "Resources" below, for an example of an erroneous ThruLine.)
- *Ancestry's ThruLines are derived from all user trees, and may not represent what you or your matches have on your own trees.
Tips for identifying matches
- The Genetic Genealogist: Are You Doing Everything to Identify Your Matches? March 11, 2017: Tips from Blaine Bettinger
- Masterclass: How to make the most of your DNA results: From LostCousins newsletter, 9 August 2019; strategies for analyzing Ancestry matches including searching for surnames and birth locations; recommended by Paige Kolza on G2G March 18, 2020
- Understanding Cluster Matrices from Dana Leeds
- Autosomal DNA Table of Consanguinity This elegant table created by WikiTree member Edison Williams can be used to identify our relationships to various descendants of our ancestors. It includes the expected amount of shared DNA for each relationship, both in centiMorgans and percentages. Studying how those expected amounts change as you move across or down the table can help you understand and visualize how DNA inheritance works.
- Or you can consult this Autosomal DNA table from ISOGG for another reference that lists average match strengths for various relationships.
Organizing your match information
- Here's what I've done. This section is adapted from one of my own G2G posts. No one has to do things my way, of course, but I feel very strongly that a list of matches, even the identified ones, must be organized into a coherent set of records if it is to be maximally useful.
- Start with Ancestry*, particularly if you are a subscriber so you can take full advantage of the information that may be connected to your matches. Analyze your matches one by one beginning with the strongest. Start a list, grouping your matches by most recent common ancestors, when you know them, or family group if you don't know the MRCAs (the family group will be determined by shared matches, and some groups can be more specifically identified than others). One way to get started is the Leeds Method (see the resource list below). In the beginning, the matches without trees will go into the family groups, but you may be able to do more with them later.
- *Obviously, this comment only applies to those who have tested with Ancestry. I recommend Ancestry as the first test for most people, due to their large user base, option for downloading raw DNA, and pretty-good user tools (except for the lack of chromosome detail).
- Also set up a chart of your ancestors (i.e. a tree or a fan chart) and check off which ones are validated by DNA.
- Then, if you have the time and ambition, start a set of chromosome maps (see below).
- Meanwhile, build out your tree by tracing the descendants of the siblings of your own direct ancestors, starting with the more recent and working back.
- As you get oriented, you should be able to see which of your ancestors are questionable (not validated by DNA) as well as where you have large groups of mysterious matches. Those are the ones I would pursue. There are various ways to try and identify your matches (see above), including contacting them.
- And after you've done all that, and depending on what you want to spend, for the difficult ancestral lines you could try some targeted DNA testing.
Taking a closer look
- The weaker the match, the more uncertain it is. It helps to have chromosome detail, which some testers provide, but which Ancestry does not. In order to get the chromosome detail for Ancestry matches, you can ask the matches to upload their DNA raw data to GEDmatch.com. Upload instructions are included on the website. (It will be necessary to sign up for the free GEDmatch account in order to view the instructions. Log in first, then use the link.) You will also find some educational links on the GEDmatch home page. Here are a couple others:
- Beginner GEDmatch: What Toolds Should I Use First? from FamilyHistoryFanatics.com
- A Really Basic Approach to Using GEDmatch Kitty Cooper's Blog, February 18, 2021
- Geneticaffairs.com offers automated cluster analysis. What this does is group DNA matches by shared DNA and presents the information in a visual format. See this example. Each colored square is one person, and the colored groups are people who share common ancestors.
- Unfortunately, since 2020 Ancestry has refused to cooperate with Genetic Affairs, but data from other DNA test providers can still be analyzed (I think). GEDmatch also offers cluster analysis as a Tier 1 service ($10 per month).
- Roberta Estes: Genetic Affairs Instructions and Resources (August 13, 2020)
- Convert old AutoCluster reports to Excel (February 23, 2021)
- There are also some resources listed in other sections of this page.
- Blaine Bettinger, The Family Tree Guide to DNA Testing and Genetic Genealogy, Family Tree Books, Cincinnati, Ohio, 2016
- International Society of Genetic Genealogy (ISOGG) Wiki
- Ventura County Genealogical Society list of genetic genealogy links last updated September 2020; a comprehensive list of links organized by category and date--sections include Getting Started, Tutorials and Basics, and much more
- Kitty Cooper's Blog: A Really Basic Approach to Using GEDmatch February 18, 2021
- Jim Bartlett's Segmentology blog, including
- Getting Started with Autosomal DNA Part I November 22, 2015
- Download Your AncestryDNA Matches in 10 Minutes! posted April 9, 2020
- Roberta Estes's DNAeXplained blog. Well worth reading through the archives and subscribing to the blog posts (free); many useful posts including those below. Please note that the links I've provided may change over time as earlier posts are archived (use the dates I've provided to find them), and that sometimes it is necessary to scroll down the page to find the post I've listed.
- The Concepts Series beginning February 18, 2016: A series of posts covering basic concepts in genealogical DNA.
- Concepts: inheritance June 11, 2020: A basic primer on the types of DNA tests and which ancestors we inherit our various types of DNA from.
- Concepts: Chromosome Browser – What Is It, How Do I Use It, and Why Do I Care? April 21, 2020: The value of chromosome (segment) detail. To locate post, go to April 2020 archive and scroll down the page if necessary.
- WikiTree and DNA November 4, 2013
- The Leeds Method September 26, 2018: Explains how to use the Leeds Method to create a spreadsheet that groups DNA matches according to "grandparent" quadrants.
- Why Are My Predicted Cousin Relationships Wrong? October 21, 2013
- Shared cM Project 2020 Analysis, Comparison & Handy Reference Charts April 9, 2020: This post includes comments on problems in using this crowd-sourced information. To locate post, go to April 2020 archive and scroll down the page.
- Genetic Affairs: AutoPedigree Combines AutoTree with WATO to Identify Your Potential Tree May 24, 2020: Title is self-explanatory; because this is a current link, when using it later you may have to access Estes's archives.
- Identifying Unknown Parents and Individuals Using DNA Matching June 29, 2019
- Triangulation Resources In One Place December 16, 2020
- A Triangulation Checklist Born From the Question "Why NOT Use Close Relatives for Triangulation?" April 18, 2021
- Y-DNA: Part 1 - Overview and Y-DNA: Part 2 - The Dictionary of DNA January 2020
- Y-DNA: Step-by-Step Big Y Analysis May 30, 2020 (access archives if necessary)
- Y DNA Resources and Repository January 2, 2021
- Four Quick Tips to Make Your Mitochondrial DNA Results More Useful May 7, 2020: This page includes links to other Estes columns explaining mtDNA in detail.
- Haplogroup Matching: What It Does (and Doesn't) Mean February 3, 2021
- Using Mitochondrial Haplogroups at 23andMe to Pick the Lock May 6, 2021
- The Concepts Series beginning February 18, 2016: A series of posts covering basic concepts in genealogical DNA.
- Randy Seaver's Genea-Musings blog
- Who Were the Parents of John Richman... April 28, 2020: Seaver explains how he used Ancestry's ThruLines in combinations with analysis of candidate families in Hilpertson, Willtshire to try and identify the parents of his ancestor John Richman.
- Researcher Beware - Sometimes the AncestryDNA ThruLines Are Wrong May 3, 2021: On the other hand, here Seaver provides an example of Ancestry making a wrong connection.
- DNA Color Clustering: The Leeds Method for Easily Visualizing Matches Dana Leeds explains.
- WikiTree's How to Get Started with DNA
- WikiTree DNA Categories (list of help pages and projects)
- WikiTree's Getting the Best from DNA This is apparently a link the Greeters send to those who've posted their DNA test information to WT.
- WikiTree's DNA FAQ
- WikiTree's DNA Project Resources Page
- DNA Confirmation Citation Maker app for use on WikiTree
Helpful G2G discussions
- DNA Triangulation February 4, 2020: More than the title suggests; several people discuss how they analyze their matches; one person links to his free-space page describing how he attempted to break down a brick wall.
- I don't know how to use DNA April 3, 2020: Here are some tips given to a beginner.
- How I Used DNA to Find My Cousin's Great-Grandfather January 11, 2020: Omar Butler explains (in a linked article) how he used GeneticAffairs's AutoCluster and AutoTree tools and DNAPainter's "What Are the Odds?"
- Version 4.0 of the Shared cM Project is now available March 27, 2020: Links to Blaine Bettinger's blog post announcing his update; Edison Williams explains the usefulness of the shared cM numbers as well as some of the limits to our understanding of genealogical DNA. (See also list of Estes posts above.)
- Did you know WikiTree integrates with GEDmatch, MitoYDNA, and DNAPainter? December 12, 2019: Peter Roberts explains.
- 23andMe adds features to "Your Family Tree" March 1, 2020: Various WikiTreers discuss how to use 23andMe's DNA information.
- Are you an AncestryDNA tester but not an Ancestry.com subscriber? April 20, 2020: Several people describe how they use Ancestry to identify their DNA matches even without a subscription.
- 52 Ancestors Week 25: Earliest June 18, 2019: SJ Baty explains how he used a combination of autosomal and Y-DNA to confirm his descent from an early ancestor (scroll down to SJ's answer, which includes the bold heading "Henry is the 21th great grandfather of SJ").
- Not all small DNA segments are junk, according to this post. April 23, 2020: Some discussion of small segments and "false matches."
- Can someone help me read DNA results...? June 27, 2020: Edison Williams discusses the effects of pedigree collapse.
- DNA Genealogy - What's the best sequence to do things in... January 21, 2021: Several WT members offer tips.
- "I don't think we've even come close to realizing the potential of genetic genealogy." December 17, 2021: Discussion of Brit Nicholson's website and his work with GEDmatch.
- Help interpreting (4594cM) outlier results January 3, 2022: Edison Williams explains centiMorgans including full sibling matches and gender differences.
- Are there new explanations of pile up regions? February 11, 2022: Edison Williams explains pile-ups; includes a link to his "cheat-sheet."
- Latest Big Y-700 DNA Test April 3, 2020: Edison Williams discusses the new Big Y test.
- DNA on William Smith, PGM Beyond New England project profile June 6, 2020: Edison Williams answers a question about the uses and limits of Y-DNA testing.
- I need info about the y-dna test... February 26, 2021: Includes helpful comments by Barry Smith and Edison Williams, among others
- On what criteria (are SNP branches) decided on... March 22, 2021: Barry Smith provides detailed explanation.
- So what is ethnicity anyway? June 1, 2018: A lively debate.
- A new angle on the use of DNA to solve cold cases (hopefully) Sept. 30, 2021: Includes informative discussion of law enforcement procedures by Edison Williams
- The Journal of Genetic Genealogy is Back in Publication Dec. 24, 2021 post by Edison Williams
Chromosome mapping identifies your DNA by the ancestor it came from. It is a powerful aid in identifying your DNA matches (which is useful for confirming, and possibly extending, your family tree). One approach is to map your chromosomes back to your four grandparents using simple yes/no choices for each separate paternal or maternal segment. Later, you can try and go further back.
As you might expect, it is necessary to have chromosome detail in order to do chromosome mapping. Some DNA testing companies provide it. The largest, Ancestry, does not. In order to obtain chromosome detail of your Ancestry DNA data, you can upload to GEDmatch.com, a free DNA matching website. Instructions on uploading are included on their website. GEDmatch is also useful for comparing DNA results of people who have tested with different companies.
Other DNA testing companies also offer the opportunity to upload Ancestry (and other) DNA data, and can provide chromosome detail. Roberta Estes provides instructions here.
At least two approaches to chromosome mapping that don't involve software or enormous spreadsheets can be found on-line: 1. Blaine Bettinger's visual phasing (see Resources list). It depends on having a sibling who is DNA-tested, preferably two. 2. Jim Bartlett's triangulation groups.
My chromosome maps are created using a modified version of Blaine Bettinger's Visual Phasing. See my personal map which I have posted to my WikiTree profile for the use of my matches. (Note: What I have posted is a summary; the detail comprises one map for each chromosome where my DNA is compared to my siblings' and our matches.)
The website DNAPainter.com also provides some mapping options. (I confess to not having kept up well with their newer features; the site is definitely worth exploring once you have mastered a few basic concepts.)
Resources for chromosome mapping
- ISOGG Wiki discussion of chromosome mapping
- Blaine Bettinger's Visual Phasing instructions
- Family History Fanatics' "Can You Do Visual Phasing With Only Two Siblings?" (answer: yes)
- Jim Bartlett's segmentology: Triangulating Your Genome
- DNAPainter Free for basic subscription; $55 (U.S.) for premium service including multiple trees.
- Login to request to the join the Trusted List so that you can edit and add images.
- Private Messages: Contact the Profile Managers privately: George Kelts and Lynn Kelts. (Best when privacy is an issue.)
- Public Comments: Login to post. (Best for messages specifically directed to those editing this profile. Limit 20 per day.)
- Public Q&A: These will appear above and in the Genealogist-to-Genealogist (G2G) Forum. (Best for anything directed to the wider genealogy community.)