The fact that genetic genealogy has revolutionized genealogy research and brought about the marriage of science and family history is without dispute. Yet DNA testing is a tool that many have either not utilized or have been unsure of the science behind it. You need not be "geeked out" on the science, but a basic understanding of the biology behind your chromosomes and genetic inheritance is essential to understanding how DNA testing can help with your research.
The presentation was well attended, with a diverse group of genealogists, some of whom had done DNA testing and others had not. Dr. Lacopo did a good job of explaining the science behind DNA testing and what the various companies that provide the testing offer without losing the audience with the science. Based on the question and answer period, he also did a good job of relating what types of genealogical problems that DNA test can and cannot solve.
Though I have already tested my DNA at two of the three major providers and was familiar with triangulation, I was able to glean some ideas from this presentation.
I was particularly interested to hear him describe his method's of using DNA testing to solve brick wall problems. I was familiar with his blog, but it was nice to hear him in person. I kept hoping I would recognize one of the family names he would mention.
The best quote I heard from him was the maxim that "human beings are not renewable resources" in relationship to the fact that we need to gather DNA from older living relatives now before they are gone. Their DNA might hold the keys to unlocking family mysteries you are trying to solve. Dr. Lacopo stressed that genetic genealogy is a numbers game, the more people with known relationships you have tested the better.
Key takeaways from the presentation were:
- DNA testing is a numbers game; the higher the % of matching DNA, the more definitive the relationship
- Size does matter; the larger the segment of DNA you share with a match, the more likely you received the segment from a common ancestor
- More is better; the more people you test with a known relationship the better
- Triangulate and map; once you identify your most recent common ancestor (MRCA) and confirm with another that match on a particular segment
Dr. Lacopo gave some tips regarding the numbers game of DNA testing - that any match over 0.3% is a big deal and that any matching segment longer than 10 cM (centimorgans) has a 99% change of being identical-by-descent, meaning a definite match. He suggested that you focus on those matches rather than the smaller matches, even thought the DNA testing companies pull in results as low as 7 cM.
The presentation inspired me to work anew on my DNA genealogy, and strive to map out the research plan for the problems I want to solve and seek out cousins to have tested. I have started compiling my own spreadsheets of DNA matches, and was impressed to see his color-coded DNA segments that he had identified as belonging to certain family names.
This was my first interaction with one of the "rock star" genealogists, and I must say that I was impressed. I would highly recommend attending one of Dr. Lacopo's presentations if you have the opportunity, and this was a great program put on on by the historical society.
A bonus was that one of the members of the society brought their pedigree fan chart to the presentation and by glancing at it, I noticed we have several points of connection on my mother's side. I handed him my business card and hope we can begin corresponding soon.
2 comments:
Thanks for the kind words! Using and understanding DNA as it applies to research can be a bit tough at first, but the rewards are well worth the brain strain! And we do have a surname in common: I have a Sherk/Schürch ancestor in Lancaster County, Pennsylvania, as well. :)
Appreciated your talk and handouts, looking forward to making some breakthroughs using DNA. Interesting to hear that we have some common Sherk/Schürch ancestry.
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