DNA evidence: takeaways from SLIG

Last month I mentioned prepping for a week-long immersion in Meeting Standards Using DNA Evidence—Research Strategies, led by Karen Stanbary, CG, at the Salt Lake Institute of Genealogy (SLIG). It was a tremendously valuable experience. I’ll share some takeaways here.

Genealogy standards offer us guidelines—best practices—in conducting research and analysis and in writing up our assertions. They aren’t hard and fast “rules,” and in some cases if you ask a handful of experts to review a conclusion and determine whether the standards have been met, you might get different answers. This is one reason why peer-reviewed genealogy articles and portfolios for certification have three or more reviewers. This variation in interpretations applies to both documentary evidence and genetic evidence.

To be clear, pretty much all the standards apply to DNA too. But there are a handful of standards that are DNA-specific.

While all the experts giving presentations in this SLIG program were generous with sharing their opinions, they all made clear that their opinions were their own and they were not speaking on behalf of any organization. The class featured animated discussions and debates!

SLIG 2020 panel

Panel of experts: Karen Stanbary, David Rencher, Tom Jones, David Ouimette, Angela Packer McGhie, LaBrenda Garrett-Nelson

Some of the DNA issues we tangled with:

  • How big does a chromosome segment match need to be? If we want to use a smaller segment, are there strategies we can employ to support why we consider it reliable?
  • How many autosomal match pairs are sufficient?
  • Does triangulation add credibility to our conclusion?
  • On a Y-DNA test, how many markers are sufficient?
  • How far back do we have to prove our matches’ trees?
  • How do we best document those lineages of our matches for readers? For example, we may have dozens of matches and need to prove each parent-child connection back to the Most Recent Common Ancestor. If writing for publication, or for a portfolio for certification, there are page limit constraints.
  • We may only prove the lineages of our matches on the specific line back to the common ancestor, but for autosomal DNA evidence, we must also consider how complete their trees are on the other lines (think fan chart). We could have more than one common ancestor and the DNA may have been passed down from a different line. If their trees are incomplete, what can/should we do to mitigate that?
  • What is the best source to cite to back-up a claim that the amount of shared DNA is consistent with the relationship we hypothesize?
  • Our evidence must be verifiable by the reader. With documents, we provide citations to identify where we found the information so others can view it too. With DNA, what options do we have to provide ‘verifiable’ evidence of matches and still meet the standard of respecting the privacy of living people? (One of the few unanimous answers we got was that if we ask a match for permission to include their results in a case study and they say no, then no. We may not include them. But what if they agree to be included, but they are not willing to copy their DNA data to a publicly accessible location, like GEDmatch? How do we meet the ‘verifiable’ standard if they have tested at, say, AncestryDNA?)
  • If someone never replies to our request to include them in our case study, can we give them an anonymous label, like Tester A, and include them?
  • Do we always need DNA evidence? If not, when do we and when don’t we?

This is just a sampling. There were so many more! And there is rarely one right answer that applies to all situations. We walked through several case studies to discuss how each expert interpreted the standards in their research strategies and in their writing choices, so that we would develop better decision-making skills in our own work.

You can do this too! Pick up a copy of Genealogy Standards, second edition, by the Board for Certification of Genealogists. It’s not just for professionals–every genealogist who wants to draw accurate conclusions should try to meet these standards. Read that, and for examples of how to apply those standards, check out the National Genealogical Society Quarterly. Many issues over the past five years carry an article incorporating DNA in a case study. Your library may carry copies, or you can join the National Genealogical Society and access past issues from their archives online.

SLIG 2020

I captured a few general tips and reminders from the class to share here too.

  • I like Karen Stanbary’s metaphorical Big Whiteboard of Assumptions. We all make assumptions in our genealogy research. Maybe we assume that church records for a time period and place don’t exist. Or that two siblings had the same mother. Or that triangulation of DNA segments is significant. I need to be alert to when I’ve made an assumption and note it somewhere then and there to address later, not wait until I’m writing up my case, when I’ve forgotten some of those assumptions.
  • We should try as hard to disprove a hypothesis as we do to prove it.
  • DNA is not a shortcut to avoid completing reasonably exhaustive documentary research. If records might exist somewhere (not just online!) that a competent genealogist would consult to find direct or indirect evidence about our subject or his/her extended family, friends, associates, and neighbors, we still need to look for those records. Having good DNA matches doesn’t change that!

I’m grateful to all the instructors who shared their wisdom in this course, and all my classmates who contributed opinions, insights, questions, and support. If you get the opportunity to take this program at a future genealogy institute, I highly recommend it!

13 Feb 2020 Edited to Add: My classmate Nicole Dyer has written a much more detailed blog post about the class, published 6 Feb 2020, at https://familylocket.com/blog/. It includes links for books and a list of case studies in journal articles you can pursue too. You can check out Nicole’s great article at “Strategies to Meet Standards with DNA Evidence: a compelling SLIG course”.

I’s also like to recommend the 2019 book Advanced Genetic Genealogy: Techniques and Case Studies, ed. by Debbie Parker Wayne, CG, which includes case studies and a chapter on standards and much, much, more.

© Feb 2020, Ann Raymont, CG®

6 thoughts on “DNA evidence: takeaways from SLIG

  1. Shannon Lynn Green

    You posted such interesting questions that were discussed! I wish I was in the class with you and could have heard all of the answers to those questions discussed. Maybe next year…

    Liked by 1 person

  2. Ariana

    Thank you for your article.

    As well as a tree that is complete, we need a tree that is CORRECT.

    Records can lie, people can lie; but DNA never lies. Without triangulation, a match CANNOT be proven.

    In one Census record my grandmother, Jemmie, was listed as a boy. Records can lie.

    Do we need DNA evidence, you ask. A resounding, Yes. I know of a family where the mother had 4 children while married. Dna has since proven that child 2 and child 4 were fathered by a man up the street. Child 3 died at age 50 and there was no Dna test; but, he had a speech impediment like the man up the street. Duh……A bunch of wrong birth certificates…..

    We cannot judge other people.


  3. Pingback: DNA evidence: takeaways from SLIG — DNAsleuth | Ups and Downs of Family History V2.0

  4. Nicole Dyer

    Great write-up of our class! I enjoyed it and was glad to sit with you. The triangulation discussion was fascinating. I was surprised to see Jim’s example of such a large triangulated segment that wasn’t connected to any of his other clusters in the network graph. So many things to consider in a body of evidence.

    Liked by 1 person


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