During Fort Wayne Ancestry Day's Ask the Experts Panel, we received so many questions that we were unable to answer them all during the event. The following are questions asked and The Genealogy Center staff's responses.
The four DNA matches for my brother said that it didn't match their lines. Where do I go from here? (My brother has passed away).
This is hard to answer. I presume you had a Y-DNA test done, but I don't know how many markers were tested. Depending on what company has the sample, you might consider having the maximum number of markers tested and then look for possible comparisons. I have found 37 and 67 marker matches to be useful - anything less than that is not significant. It may be that no other male under your last name has provided a sample or that you are a close match to some other surname.
DNA Testing. After getting a test result, where do we go to get help in interpreting and follow-up. My results seemed very generic and didn't give me a good point to continue on.
I presume that you tested with Ancestry. Most testing companies have a tech support area to answer further questions and provide guidance. You should call 1-800-ANCESTRY and ask to be directed to someone who can help.
Recently did the DNA Maternal and Paternal. Have a couple of matches for one family and zero for the other set. Now what? Where do we go with DNA info we match and with family we don't have matches with?
There are two different types of DNA tests available for genealogists: Y-Chromosome tests, which examines Y DNA passed from father to son and allows males with that chromosome to match other males. The other so-called female test is a Mitochondrial DNA test, which compares DNA found in the cells of women and passed down through their daughters. Sons inherit their mothers' DNA but do not pass it down. Currently, there is no way to develop matches to other surnames through mitochondrial DNA. The tests will show what large Haplogroup you belong, and what subgroup within that group. If you think you and a cousin share the same maternal line, you can do a comparison. Otherwise, the data from a mitochondrial test is too general to be meaningful genealogically. Y-Chromosome testing is different and offers more promise for a match. This is because there are a number of fast-moving markers on a Y-chromosome (by "fast-moving," we mean that there are mutations that can occur within a genealogical time frame of a few hundred years or less). So for genealogical purposes, I recommend the Y test, and that you test other male relatives who share the same unbroken male line, and I would recommend at least a test involving 37 markers (anything less is too likely to create a false positive match). A 67-marker test is even better. If you have a match, you can be assured that you have a common ancestor. A very close match, say 65 out of 67 markers, means that you may have a common ancestor in the last 100 or 150 years (scientists are still trying to work out the mutation rates of various markers). If you don't match another male-line descended relative with whom you share a common male ancestor (and it has to be an unbroken male line), then something called a "non-paternal event" has occurred. This means that somewhere in either your or your cousin's line, an adoption or pregnancy occurred where the paternity was different than what was believed. Ideally, results should be compared with a group of male-descended cousins or people with the same surname.