DNA: Which Test and Why?
(a talk by Joyce Fingland)

Saturday, March 24, 2018

Joyce Fingland gave a presentation “DNA: Which Test and Why?”. Joyce explained that there are several types of DNA test available:

• Y-DNA testing (done until recently only by Family Tree DNA) is only available to males, and is really only useful when wanting to determine if two known men descend from the same male, e.g. a great-great-grandfather in common. Obviously both men must take the test in order for it to work.
• MtDNA, or Mitochondrial DNA, is passed from every woman to her female descendants. It is not useful for genealogical purposes, since it would only tell you that hundreds of generations ago you had a female ancestor in, say, Europe.
• Autosomal DNA, sometimes called “Family Finder” testing, enables your DNA to be compared to that of other individuals who have taken a test with the same company, or else have added their test results to other third-party sites. This permits you to find extended family members. Joyce stated that autosomal testing offers the best starting point, and is the least expensive option. It can sometimes help solve family mysteries, or debunk myths.The “Origins” report which each testing company provides is the least accurate and useful part of the testing, despite the Ancestry ads which show a man exchanging his kilt for lederhosen: Joyce demonstrated the difference between her first Origins report from FTDNA which indicated more French-German origins than UK, and a new report after the company revised their algorithms which showed her (more correctly) with a much higher percentage of British ancestry. Even at that, the Origins Report is not what genealogists are after: they want to find relatives who share ancestry several generations back.

Joyce mentioned that there are three major companies who have been performing DNA testing for genealogical purposes for a number of years: Ancestry, FamilyTreeDNA, and 23AndMe. She outlined advantages and disadvantages of testing with each company, and also mentioned a couple of newcomers to the industry, MyHeritage and LivingDNA.

Joyce stressed the importance of putting up a family tree at the site where you test, to accompany your test results. In that way those who are found to “match” you — that is, to share portions of your DNA — can look at your pedigree chart to figure out where you match them. There is also a well-used free third-party site, GEDMatch.com, to which you can upload your raw data results from your own testing company and have them compared against those who tested with one of the other companies, thereby increasing your chances for matches.

If people wonder “why bother finding 4th or 5th cousins?”, Joyce told us that she found a match through GEDMatch to two sisters who were her 4th cousins. These ladies, who were 84 and 97 when she began to correspond with them, decided that she would be the best new guardian for the set of letters written between 1854 and 1886 by Joyce’s great-great-grandfather to his niece, their great-grandmother. What a treasure!