Great discussion of DNA on line here.     Want to add a couple of things.  We need to keep stressing to Newbies that Ancestry and 23 offer only the autosomal DNA test. This is now much more useful than it used to be as far as matches go.  People who have not done genealogy before and don't already know their 2nd-5th cousins (or what they are) will be thrilled, I am sure, to get these matches.  I just have heard a lot of disappointed people saying, "Oh, I am 100% European, didn't learn anything."  Well, duh, yes.  Those of us doing genealogy for decades have already located many of those cousins by paper trails and mail (imagine that!).  And those cousins were happy to hear from me even when I had to explain what a second cousin was.     I keep saying that I think the autosomal test is most useful for mixed race people, those with adoption walls, and those who suspect infidelity in the line.     Yes, Ancestry has the largest database, but FamilytreeDNA offers the most tests.  I began with a small Y test on my brother's DNA, and have followed up by having about eight tests done on that same sample, the mt-DNA, ones with more markers on each, and finally the autosomal.  I even got my sister and me to take the latter because we DO have a paternal grandmother adoption ca. 1884 that has been a brick wall as long as I have known about it--and that took five years in itself.  No solution yet.     I am more interested in getting back farther with ancestors than in finding cousins, but to each her own, of course.  After 30 years of work, we finally have our surname place of origin in England due to London church records coming on line; but it is the Y DNA that told us specifically that the two brothers or their sons in Ipswich, MA, in the 17th century are not brothers or cousins at all.  So far the specific paternity event is only a guess, but we would never have known this without a Y test that looks at slow mutations over centuries.  The test also finally proved to some other descendants that our ancestor left Massachusetts early on and immigrated up the Hudson River.  No one believed me until we had the Y test done.     Debbie offers some great suggestions below, so I hope newbies will copy her post and refer to it as you learn more.  I just bought Blaine Bettinger's book on genetic genealogy, after borrowing it from the library, and am referring to it constantly. I used to be able to explain genetic genealogy to people, but it has now gathered speed and passed me by.  More and more is possible, so I hope I find out where my paternal grandmother came from before I die.     And, I don't brush off the autosomal test at all.  Just this month, I heard from an Irish second cousin whose family I know well.  She took the autosomal test and reached out to some near matches.  To our surprise, poor great uncle Bertie who we thought was childless was anything but.  On one of his engineering jobs out from Ireland to the West Indies in the 1940s, he left two daughters who were thrilled to find us and get photographs of their father.  Our tree has now added more people of color to the Japanese-Americans already in it.  Our heads spin with a tree world more diverse than we ever imagined. Elizabeth On 6/5/2018 11:31 AM, nyc-roots-request@rootsweb.com wrote: > Date: Tue, 5 Jun 2018 11:21:11 -0400 > From: Debbie<debidub@gmail.com> > Subject: [NYC-ROOTS] Re: DNA testing > To: NYC-ROOTS Rootsweb<nyc-roots@rootsweb.com>, > floridamarbil@gmail.com > Message-ID: > <CALUxgCUYnH5WeHzg3PapBUhHTFKG3h1K0At2Z1XBZg1Vwc2RrQ@mail.gmail.com> > Content-Type: text/plain; charset="UTF-8" > > Hi Bill, > I've been working with DNA for a number of years now. A couple of thoughts > regarding your post. > > First, when it comes to the "ethnicity estimates," remember that they are > just that -- estimates. Each company develops an algorithm to make sense > of the data. Some of this is dependent on who is in their database, and > how big it is. That said, Ancestry's database is said to be the largest. As > more people test and the dataset improves, the algorithms are updated, and > the estimates get more accurate and more narrow -- being able to pinpoint > smaller regions. But, you will find differences in the estimates between > companies, and even with the same company over time as they tweak their > algorithm. > > Here is one article on the subject: > http://www.researchjournal.yourislandroutes.com/2018/01/dna-ethnicity-estimates-are-just-that-estimates/ > > Second, ethnicity estimates are most accurate at the continental level. > So, for example, you won't see things like "French," but instead "Western > Europe." With roots in Spain, you'd see "Western European' and "Iberian > Peninsula" and probably even some UK. We have to remember that between > wars and trade, there was a lot of intermingling of people. My Italian > roots show a mix of Italian/Greek, North African, Middle Eastern and > British. > > Third, DNA "washes out" with every generation. The saying goes that > "Everyone has two family trees -- a genealogical one and a genetic one." > For example, perhaps I had one great-great-great grandfather who was > Jewish. With every generation, the people in our family will have less and > less DNA from him. We will get to the point where the is a generation where > some, if not all, of the descendants don't have ANY Jewish DNA. We have > the paper trail to show he's an ancestor. Our older relatives have some of > his DNA. But, the youngest generation doesn't have any. > > This is my favorite article on the subject: > http://thegeneticgenealogist.com/2009/11/10/qa-everyone-has-two-family-trees-a-genealogical-tree-and-a-genetic-tree/ > > Finally, the DNA matches are very reliable and of more use to your > genealogy research. I'd focus my energy there. > > One of my all time favorite webinars on using DNA for genealogy is Blaine > Bettinger's 5-part series "The Foundations of DNA," which is offered > through Legacy. > > http://news.legacyfamilytree.com/legacy_news/2016/08/foundations-in-dna-by-blaine-bettinger-now-available.html > > I hope this helps to address some of your questions! > Debbie