When you hear the term endogamy, what communities come to mind? French Canadians, Puerto Ricians, Mennonites, Pacific Islanders, and Ashkenazi Jews are common examples. Some of these examples are from island peoples, so what about the Irish? Last time, I discussed the effect of a clearly endogamous community, Ashkenazi Jewish (AJ), on a relatively non-endogamous community, German, within my dad’s match list. My dad has more AJ matches with longer segments (greater than 20 cM),...
As genealogists we want to understand our match lists. We want to identify the matches that will give us the solid clues we need to make progress on our target ancestor’s family tree. Endogamy and its close cousins, pedigree collapse and multiple relationships, complicates that. Diana laid out the definitions in the first blogpost in this series: “Endogamy, Pedigree Collapse, and Multiple Relationships: What’s the Difference and Why Does it Matter?” Nicole wrote about strategies...
Today’s episode of Research Like a Pro is about endogamy, its effect on DNA analysis, and strategies to overcome these challenges. We discuss a client case with French Canadian and Acadian lines as well as making a network graph and analyzing it. Join us as we discuss calculating average segment size, sorting by longest segment, segment mapping, and more. Transcript Nicole (1s): This is Research Like A Pro. episode 236 Strategies for Overcoming Endogamy Welcome...
Have you ever suspected that endogamy was affecting your DNA analysis? You might notice a large number of matches from an island population or isolated area. The matches might seem to share a lot of DNA but no common ancestor can be determined. Clustering matches doesn’t seem to produce clusters related along different ancestral lines. Instead, you find one big mass of tightly connected matches. The total amount of shared DNA points to a second...
Steve Little, one of our Research Like a Pro with DNA 4 Study Group members, wrote this guest blog post about how he uses diagrams to help visualize the multiple relationships with his DNA matches. He is from a community of mild endogamy — Appalachia. I hope his insights will help anyone dealing with multiple relationships with DNA matches, pedigree collapse, and endogamy. -Nicole Don’t panic! At first glance, the swirling tangle of lines below...
Today’s episode of Research Like a Pro is about pedigree collapse and its effect on DNA matching. We discuss the coefficient of relationship calculation and how that can help you estimate the expected amount of DNA two people should share based on the relationship in their trees. We talk about the Hopper case study with a DNA match with two individuals with multiple relationships and one of the test takers has pedigree collapse on the...
Pedigree collapse occurs in a person’s family tree if one of their ancestral couples are related to each other. This causes the same ancestors to be repeated in their tree. For example, if a person’s parents are second cousins through their great-grandparents Joseph Dyer and Anna Smith, then Joseph Dyer and Anna Smith appear in the test taker’s pedigree twice. Instead of having 32 unique third-great-grandparents, this test taker has 28 unique third-great-grandparents. These diagrams...
Today’s episode of Research Like a Pro is about double cousins. Do you have any? We’ll talk about how double cousins and other relatives with whom you share multiple relationships can affect DNA match analysis and genetic network analysis. Although double 3rd cousins don’t always share an inflated amount of DNA, you can definitely tell they are double cousins in your network analysis. Join us as we discuss these issues. Transcript Nicole (1s): This...
Would you like an efficient method to find clusters of DNA matches relevant to your research subject? In this series, I’m sharing the steps to create a network graph using the free, open source Gephi application, available for Windows or Mac. I use Gephi to create network graphs of my AncestryDNA matches, but you can use matches from other companies as well. Throughout this series, I will be using my own matches from AncestryDNA, but I...
Today’s episode of Research Like a Pro is about the difference between endogamy, pedigree collapse, and multiple relationships. We discuss examples of each scenario and how it affects DNA matching and cluster analysis. Transcript Nicole (2s): This is Research Like a Pro episode 222 Endogamy, Pedigree collapse and multiple relationships. Welcome to Research Like a Pro a Genealogy Podcast about taking your research to the next level, hosted by Nicole Dyer and Diana Elder accredited...