How To Create Diagrams and Charts for Genetic Genealogy Research

This article is based on a similar article in the July – September 2022 issue of NGS Magazine and is republished here with permission.

The Leeds Method, developed by Dana Leeds, enables genetic genealogy researchers to identify clusters of genetic cousins, based on color-code assignment of close matches and their shared genetic cousins. Chart created by author.

Genealogists reporting on research should consider the use of charts, diagrams, tables, maps, and other figures to clearly communicate findings. Sometimes a chart is worth a thousand words, and in the case of genetic genealogy, a simple diagram can present information much more effectively than an extensive (and oft-times repetitive and dry) discussion in paragraph form.

Charts and diagrams can also help in the process of discovery, analysis, and interpretation of genetic genealogy data. This article describes practical, accessible types of charts, diagrams, and tools for making sense of DNA evidence.

How To Use The Leeds Method for Genetic Genealogy

Simple spreadsheet software can be helpful for prioritizing, organizing, understanding, and analyzing autosomal DNA matches. One popular approach for organizing DNA matches, the Leeds Method, employs spreadsheets to cluster DNA matches into unique groups of genetically related individuals. To use the Leeds Method, first construct a spreadsheet listing close genetic cousins, ordered from those sharing the most DNA to those sharing less DNA. Selection of which cousins to include might focus on a certain number of closest matches or a lower threshold of shared DNA.

Next, set an upper threshold (often around 350-400 cM), to exclude close genetic cousins. Close genetic cousins need to be excluded since the whole point of sorting genetic cousins is to construct meaningful clusters of genetic cousins whose relationships to each other can be explored. Including close genetic cousins will result in helpful clusters being merged into larger and less helpful clusters. For example, if a first cousin is used to define a cluster, their shared matches will include many relatives from an entire side of the tester’s family tree. Excluding this match and starting with more distant matches is more likely to result in unique clusters associated with each grandparent or even great grandparent.

Once an upper threshold has been set, analyze the first individual sharing an amount of DNA below the threshold. Assign a color to this match and all of the person’s shared matches. Then analyze the next match without an assigned color, and assign a second color to that person and his or her matches.  Repeat this process until all of the matches selected for the analysis are organized by color in relationship clusters. 

Following this process of color assignment will often result in the formation of a handful of clusters of related matches. These clusters (represented by a single color) often are composed of descendants of an ancestor or ancestral couple, descendants and collateral relatives of an ancestral couple, or endogamous populations from particular lines of ancestry. Analysis of the family trees of genetic cousins in a cluster can often reveal the likely association to particular ancestral lines and can aid in prioritization of which genetic cousins would be most helpful for exploration of a particular research question. See Dana Leeds's blog for additional advice on how to interpret the results of these color-coding efforts.

Other Genetic Genealogy Uses for Spreadsheets

Spreadsheets can also be used to prioritize analysis of genetic cousins across multiple testing platforms, and they can serve as a type of research log where annotations on relationships, research efforts, and analysis can be recorded in a single location. Until recently, several DNA testing companies offered options for downloading information regarding DNA matches. However, recent privacy and data security concerns have resulted in these features being removed from many of the DNA testing companies. Instead, information from genetic match lists might be copied and pasted into spreadsheets and then formatted for useful organization and analysis.

Spreadsheets can also be used to analyze the test results of multiple individuals—perhaps several tested siblings or multiple descendants of a research subject. Descendants inherit different portions of their ancestor’s DNA and therefore have different amounts of shared DNA with key genetic cousins. They may even have completely different key genetic cousins. Combining their DNA test results can help in prioritization of analysis for pertinent genetic cousins.

The versatility of spreadsheets enables organization and analysis of DNA test results in many ways. Application of formulas can also enhance analysis efforts and aid in prioritization of matches who may be relevant to a research question.

If you need help organizing and sorting your DNA matches, analyzing the DNA matches of several testers descending from a research subject, or working to isolate more distant genetic cousins who are most pertinent to a research question, our researchers at Legacy Tree Genealogists can help!

Tools For Visualizing Relationships: SmartArt and Lucidcharts

Once DNA matches are organized and prioritized, the next step is often analysis of individual matches or clusters of genetic cousins. Visualization of relationships and relationship levels in descent charts is helpful not only for analysis, but also for communication of findings. Two excellent digital options for descendancy charts are SmartArt charts in Microsoft Office applications and Lucidchart.

Labeled hierarchy formats provided by SmartArt options in the Microsoft Office Suite empower quick and effective construction of descendancy charts for genetic cousins through bulleted text inputs. Chart created by author.

In Microsoft Word (and other Microsoft applications), SmartArt hierarchies can be used to show relationships between descendants of a common ancestral couple. To incorporate these charts in a Word document, click on Insert in the top ribbon, SmartArt in the second ribbon, Hierarchy in the resulting list of options, Labeled Hierarchy in the second row of the chart, and OK. One way to adjust the structure of these charts is to select the Add Shape menu option in the top left corner.

For a more rapid and efficient method of changing the format and entries in the chart, choose Text Pane and make adjustments by using the tab key. Change layouts, colors, and design and shape fills through Design and Format menu options in the top ribbon.

While SmartArt hierarchies are helpful for showing the relationships between several descendants of a single ancestor or ancestral couple, they are not as versatile for depicting relationships between descendants of multiple families. To show relationships between descendants of multiple families, or as another option for descent trees from a single ancestor or ancestral couple, consider Lucidchart, one of several tools available through Lucid (https://lucid.app) with free or paid subscription options for creating charts.

Create Lucidcharts by selecting different types of shapes and lines and linking them together. While there is no text entry input to guide the formation of a chart as there is in SmartArt, the charting process is fairly straightforward and can be performed quickly.

Lucidchart, a web-based app for creating charts, can be used to demonstrate relationships between a test taker and several genetic cousins. Chart created by author.

For both SmartArt and Lucidchart, charts showing the relationships between genetic cousins and a test subject might include names, birth dates, death dates, and additional information such as names or usernames of genetic cousins and the amounts of DNA they share with a test taker.

A Tool for Genetic Genealogy Analysis: What Are the Odds? (WATO)

Another tool for visualizing relationships between genetic cousins who descend from a common ancestor is the What Are the Odds? tool at DNAPainter. An even better use of this tool is to enable analysis of competing hypotheses for where a test taker might fit into a larger tree of extended relatives, based on amounts of shared DNA.

Use the Add Parent and Add Child options to map out relationships between descendants of a common ancestor or ancestral couple. Half-relationships can be entered between siblings within a family group, and birth dates and death dates can be added for deceased generations between matches and the common ancestor or ancestral couple. Amounts of shared DNA can be entered for DNA matches. The structure and data for a tree can be imported via GEDCOM if desired. Finally, hypotheses for where a test taker might fit into a family tree can be added or automatically generated and subsequently narrowed based on documentary evidence and genealogical context.

WATO, a tool developed by Jonny Perl with input from Leah Larkin, Andrew Millard, and many others, enables visualization of relationships between genetic cousins to a test subject. It also facilitates analysis and exploration of hypothesized scenarios for how a test taker may fit into a larger extended family tree. Image courtesy of Jonny Perl.

WATO will use probabilities reported in the AncestryDNA Matching Whitepaper (original probabilities) or the updates to those probabilities published through AncestryDNA match lists (beta probabilities), in order to rank hypotheses based on their relative probabilities to one another as determined through joint probability analysis.

While DNAPainter’s Shared cM Project tool can offer insight into the probability of a single relationship between a test taker and a genetic cousin, WATO can communicate the relative strength of competing hypotheses, based on the relationships between a test taker and many relatives with documented descent from the same ancestor or ancestral couple. In some cases, this visualization can help to clarify the most likely hypothesized relationship between a test taker and genetic cousins and may even enable researchers to rule out hypotheses that are much less likely.

Conclusion

The Leeds Method, spreadsheets, SmartArt, Lucidchart, and What Are the Odds? are just a few of many tools to help organize, chart, diagram, visualize, analyze, and interpret DNA evidence in the context of genetic genealogy.

If you'd like help making sense of your DNA test results to help you accurately expand your family tree, you can schedule a consultation here with one of our expert genetic genealogists.