Visualizing Complex Relationships: Working with Pedigree Collapse, Multiple Relationships, and Endogamy

I took five genetic genealogy courses this year, most focused on endogamy, pedigree collapse, and multiple relationships. Nicole Dyer at Family Locket asked me to share something about that. This post focuses on visualizing complex relationships, such as multiple instances of pedigree collapse and multiple relationships in one DNA match (e.g., between two close cousins).

The full text of the article was first posted at Family Locket. A PDF version of the article is available here: Here is the introduction of the article; the full text continues at Family Locket.

Excerpt: Visualizing Complex Relationships: Working with Pedigree Collapse, Multiple Relationships, and Endogamy

Don’t panic! At first glance, the swirling tangle of lines below may appear to be a meaningless and unmitigated mess. However, this is not the case when we consider how it was assembled. Approached in small steps, simple, smaller, easily-understood diagrams can be assembled and combined to simultaneously display information that may not be appreciated when spread across multiple diagrams. Sometimes the whole is greater than the sum of its parts.

But a tangle of confusion is the dilemma that some genetic genealogists may face, especially when first dealing with cases in communities where pedigree collapse, multiple relationships, and endogamy are present. At least, that was my personal experience, as I first began to grapple with my “mildly endogamous” Appalachian heritage. This post intends to help clarify for the learning researcher how to differentiate between the concepts of pedigree collapse and multiple relationships–even when they may be present simultaneously–and to introduce some methods for teasing apart and clarifying complicated genetic relationships, and how they may be visually depicted to assist in research planning and to more deeply appreciate their complexity.

family tree diagram of multiple connections shared between two close cousins
Figure 1 (CLICK TO ENLARGE): “Adam” LITTLE and “Betty” LITTLE (in green near bottom) are cousins related in several different ways, perhaps more than a dozen, including by pedigree collapse and by multiple relationships. This diagram is both simple and complex. It is simple in that it does NOT depict every ancestor of the DNA testers, but rather only those ancestors in instances of multiple relationships or pedigree collapse. It is complex in the sense that it combines several instances of multiple relationships, and it shows sources of pedigree collapse only once (whereas in a traditional pedigree chart they would be shown twice).

All 32 of my third-great-grandparents had settled into one Appalachian county by 1820 (many earlier), and 60 of my most-recent ancestors were born, lived, and died there, in Ashe County, North Carolina. My parents left Ashe County in the mid-1960s, the first of my direct ancestors to leave Ashe in 140 years; sometimes they say they escaped (left of their own free will) and at other times they will say that they were exiled (“asked” to leave); both are in jest. The only people who love Ashe County more than the people who live there are the people who have left there.

Anyway, a love of place and of family was instilled in me early. In the 1980s, as a teenager, I began digitizing an aunt’s decades of solid genealogy research; with the birth of my first son in the 1990s, I began my own family history research; and with the advent of DNA tests, I began the work of confirming the documentary research that my aunt and I had done.

But, with such deep roots in one county, I found myself encountering DNA challenges that weren’t apparent to many of my more cosmopolitan colleagues. For example, while they were able to produce neat and tidy Leeds Charts, mine looked like an explosion at the Benjamin Moore paint store: a riot of color; while their Gephi network graphs images looked like beautiful and meaningful color-coordinated galaxies, mine looked like a Jackson Pollock painting had been run through a shredder and swept into a clump.

So this year, 2022, was the year I threw myself deeply into learning everything I could about how to apply DNA analysis to untangle and tease apart complicated relationships in my Appalachian heritage. And it’s been a great year.

(Continued at Family Locket.) …

The full text of the online article is available at Family Locket:

One thought on “Visualizing Complex Relationships: Working with Pedigree Collapse, Multiple Relationships, and Endogamy

Leave a Reply

Your email address will not be published. Required fields are marked *