I created this web page because of so much DNA testing. I want you to know what your DNA test results mean.
As of 2018, there are 3 main DNA testing companies.
Ancestry.com has the largest database and they offer features nobody else offers.
23andMe.com has the second largest database and they offer some medical related information.
FTDNA.com (Family Tree DNA) has the smallest database but the best research tools.
Each of these "Big 3" has their advantages and disadvantages.
- Ancestry.com offers no tools for diagnosing your DNA test results but they do offer the best genealogy research tools and the largest (and perhaps best) available online family research software of any commercial company. These features come at a cost.
- 23andMe.com is the only major company currently offering both genealogy and medical DNA results. However, their genealogy matching tools are so secure that it is really hard to find out WHY you match someone. It's also really difficult to correspond with them once you find your match.
- FTDNA.com has a database of DNA matches that's significantly smaller than the other two companies. But as you'll see below, they are the only company who offers other types of DNA testing which means that no other company can show you people who match you through more than one type of DNA test. Also, FTDNA is currently the only company that allows you to upload your test results from another company to their database for free.
Other companies, like MyHeritage.com, also offer DNA testing. These are growing.
MyHeritage uses the same lab as FTDNA but not the same database.
PLEASE NOTE: If you only test at Ancestry.com and someone else only tests at FTDNA.com, you will never know if you match them unless you both upload your results to a third-party DNA site.
Types of DNA Tests
All these companies offer what's called an "autosomal DNA" (AUTO-sum-ul) test, sometimes refered to as "atDNA." I'll explain below what that means to you. This is the only type test offered by both Ancestry.com and 23andMe.com.
FTNDA.com also offers both "yDNA" tests and "mtDNA" tests. mtDNA is mitochondrial DNA (my-toe-KON-dree-ul) DNA. FTDNA.com is the only major company that offers these important (but expensive) tests for genealogy. I'll first explain these two tests. Then you can get a better idea of what an autosomal test does not do.
This is called a "DNA Inheritance Chart"
The DNA Inheritance Chart above shows how yDNA and mtDNA is inherited and passed on.
mtDNA
The ancestors in RED are all women. Only females can pass down mitochondrial DNA (mtDNA). They pass it down to ALL their children but only their daughters can pass it down to their children. Men cannot pass it down but they can inherit it from their mom. If you and and your sibling take an mtDNA test it will tell you if you both had the same biological mother.
An autosomal test can tell you if you and your sibling have the same parent but it won't tell you if that parent is your dad or your mom unless you both also match a third person who is only related to that parent and not your other parent.
An mtDNA will match EXACTLY the mtDNA of all your biological cousins from your mother's sister, AND her mother, AND her mother's sisters, and their mother, and their mother's sisters, and so on back for many hundreds of years. mtDNA does NOT change often. It can remain the same for generations whereas autosomal DNA is so "watered down" from one generation to the next that, after a many generations, it's impossible to tell if you're related to another person.
My mtDNA tells me there was a black lady who lived many, many hundreds of years ago from whom I descended. We do not know her name. We do not know when or where she lived. We may never know. But we know she existed because my mtDNA proves it. My mtDNA would closely match her mtDNA even if she had lived 1,000 years ago.
yDNA
The ancestors in BLUE in the above chart are all men. Only males can pass down yDNA. Only males can inherit it. It is what makes them men instead of women. yDNA tests are VERY helpful for genealogy in identifying your surname line but ONLY men can take a yDNA test.
If your last name is "Smith", "Gonzales", "Nguyen", or some other very common surname, a yDNA test will tell you for certain if you are biologically related to someone else with the same surname.
You cannot take a yDNA test if you are female. Females do not carry any yDNA. Get your brother to test his yDNA. Your brother cannot find out if his yDNA matches your mother's father's yDNA. Your mother cannot pass down her father's yDNA because she is a female. yDNA is only passed down from male to male.
That's a good thing. That's why yDNA tests are so helpful in identifying your surname line. It will tell you for certain what the surname of your great-great-great-great-grandfather was if you match someone who has found his name using traditional genealogy, but ONLY if they can prove it with sources and ONLY if there are others who match who have similar research.
atDNA
If all the ancestors in blue squares are male and all the ancestors in red circles are female, what about your ancestors in the white squares or circles?
The white squares and circles are your autosomal DNA (atDNA) ancestors. They're who gave you your autosomal DNA. An atDNA test is the only type test available at Ancestry.com, 23andMe.com, and MyHeritage.com.
FTDNA.com also offers this test but they are the only company that offers the other type tests.
Autosomal DNA matches include those who may match from a yDNA or mtDNA test.
You naturally ask, "So, why not just take an autosomal DNA test and skip the others?"
People test their yDNA or mtDNA because these tests give information an autosomal DNA test cannot give.
An autosomal DNA can show you a 1st, 2nd, or 3rd cousin match. It may also tell you if you match a 4th or 5th cousin but that's probably the limit.
There are a couple of annoying things about an autosomal DNA test.
1) It cannot match you with distant cousins accurately. 4th cousin matches are often guess work. There is a chance they could be wrong EVEN when that person has matching genealogy.
2) An autosomal DNA test cannot tell you the family line on which you match another person. Your match could be related to any of your 4 grandparents, any of your 8 great-grandparents, or any of your 16 great-great-grandparents or any of their descendants.
If your DNA matches their DNA you may think you know the ancestor you have in common. However, it could be another ancestor or no ancestor at all. Sometimes autosomal DNA matches aren't real matches. It depends on how long ago the ancestor lived. 4th cousin matches and higher are notoriously inaccurate.
That's why I always tell people that an autosomal DNA test is only good back about 5 generations. Beyond that, there are way too many false matches. Testing companies show you all your matches and let you decide which are real and which are false.
People often want to know who the family of a particular ancestor was, where they lived and who their descendants are. I always recommend that females consider having a male relative with the desired surname take a yDNA test at FTDNA.com.
An autosomal test can give you a "best guess" at who your family is related to but a yDNA test can tell you beyond a shadow of a doubt whether or not another person is your biological match.
For example, my mother's great-grandfather was Jesse Kirby Smith. For decades we never knew who his father was or where his family came from. On census records, he said his parents were from Georgia. That's all we knew.
We had to wait 'til yDNA testing became a more perfected and popular technology. Then a direct male descendant of Jesse Kirby Smith took a yDNA test. We knew right away who his father may have been. An autosomal test would not have told us anything because Jesse Kirby Smith lived too long ago.
yDNA testing accurately shows matches to a common ancestor's descendants even when the ancestor lived hundreds of years ago, sometimes thousands of years ago.
I provided a saliva sample for a sophisticated yDNA test I was asked to take. With these test results I was joined with a test group that matched me with 3 others. Their ancestors were Vikings.
Their Viking ancestors had settled around Yorkshire, England about 1,200 years ago. My ancestor definately matched theirs but mine lived about 2,000 years ago in Jutland (southern Denmark). Just the same, our yDNA was beyond doubt.
How is each type DNA inherited?
A DNA chart shows the inheritance pattern of each type DNA. When we put our on ancestors in it, the chart helps us understand which DNA we got from which ancestors.
This is MY "DNA Inheritance Chart"
The chart above is My DNA inheritance chart. I displayed it vertically to match the blank DNA Inheritance chart at the top of this page. You can CLICK HERE to view my chart a little larger.
Click your browser's "back" button to return.
For a horizontal (pedigree-style) version, CLICK HERE. It will open in a separate window.
Why "Y" or Who's who in My yDNA?
That's my name at the bottom -- Ron Vincent. To the left, in blue (to the right in the horizontal chart), is my father, Wilburn Glenwood Vincent. His father is Oakley Vincent, my grandfather. When I took a yDNA test I of course matched Oakley Vincent's other descendants who took the same test. We all match almost exactly. When you are very close relatives and all descend from the same, recent male ancestor it shows in your yDNA.
Next (in blue) is my grandfather's father, Aaron Vincent. After that, his father's (in blue) was John Vincent.
We have accurately traced our Vincent line back 350 years to another John Vincent. We can prove it. That makes 11 generations of Vincents. This is important to others who don't know this line but who descend from it.
Our yDNA matches all his other direct male descendants. Some of them spell their surname "Vinson" but they are still biological cousins.
There are other very close matches whose surnames are completely different but they are biological cousins just the same. One of these families has records to prove their ancestor was adopted by another family but was biologically a "Vinson." They've used the other family's surname for several generations.
There are others who have no records that show how they came from the Vincent line. They took a yDNA test but did not match anyone who shared their surname. Instead, they matched a number of Vincents and Vinsons. These people are still wondering when they changed the surname. They only know the name changed many generations ago.
These are what's called "undocumented births." yDNA is very accurate and very good at identifying such ancestors. The only thing it cannot tell is exactly which ancestor it was but, with the right type yDNA test, it can tell with a high degree of accuracy approximately which generation that ancestor lived in.
We have others whose surname is "Vincent" who know their ancestors back to the mid-1800s. Beyond that they have no idea who their ancestors were. Because they match our Vincent yDNA so well, we know who their most ancient ancestor was. He is the same John Vincent we descended from who lived 11 generations ago. We can prove that to them. However, we cannot tell who the people are between John Vincent who lived back then and their oldest known ancestor. These are the type things one can learn only through yDNA testing.
Oh, my! My mitochondrial DNA?
It isn't as easty to tell who my mtDNA matches might have descended from. Furthermore, I don't have many matches. That happens often. And mtDNA tests are only good for genealogy if you pay for the most expensive test.
My mom's maiden name was Doris Virginia Warren. Her mom was Lela Oney Blake. Her mom was Lillie Viola Smith, and her mom was Francis Elizabeth "Fannie" Fullman. These are all displayed in red on My DNA Inheritance chart. That's as far back as my chart goes.
We don't know who Fannie Fullman's mother or grandmother was. Our research stops with Fannie. Unlike yDNA which is easier to trace, mitochondrial DNA traces your matriarchs. In a patriarchal society like ours, this makes mtDNA research difficult.
If we were able to find out several more generations back from Fannie we might be able to discover which of my female ancestors was black or at least mixed race. However, a mixed race ancestor is very, very difficult to discover. Records from long ago are scarce and people were reluctant to be identified as "black" or "negro" prior to the abolition of slavery. So we may never know.
Where's the auto in autosomal DNA?
I'm not sure why it's called "auto." Perhaps it's because you receive it automatically from every ancestor including those who pass down their yDNA (to males) and mtDNA.
Database size matters also -- it matters a LOT! The larger the testing company's database, the more people you are likely to match. That's really important. That's why an autosomal match at FTDNA won't show you as many possible cousins as a match at Ancestry. However, FTDNA has much better research tools if you really want to get into atDNA research.
Further autosomal DNA research
At 23andME or Ancestry, you have to download your test results then upload them to another site like GEDmatch to find DNA research tools. I personally don't fool with tools much. For my money, I've found that if a person whose autosomal DNA matches mine closely, usually that person also knows how we match or can tell me enough so that I know how we match. But that's only for close matches.
Those who don't match me closely usually don't know why we match and I don't know either. Further DNA research can help with that but further research means building spreadsheets from tests of several known relatives who can prove why they are your kin. You cross-match these people with your unknown matches in a process called "triangulation."
It's a very involved and complex process that usually reveals nothing more than to tell you on which of your family lines you and the other person match. It usually can't tell you which generation, just which line.
Furthermore, the people you distantly match often don't enough about their ancestry to help achieve your research goals. Many who get deeply involved only build large databases of "cousins" with no other information. That's good if your goal is to identify all the descendants of a known ancestor but that isn't my goal. My goal in identifying cousins is to find out who their ancestors were and how we tie in together. For my Vincent relatives I've had great luck doing that through yDNA research.
Summary
If you can only afford one DNA test, and your goal is to identify as many unknown ancestors as you can, I recommend an autosomal DNA test. If the information you seek is for genealogy or to help locate a biological parent or other relative (i.e. you are adopted or don't know who your father was), get an Ancestry.com test. Wait 'til it's on sale around Christmas time or other holiday sale.
They not only have the largest autosomal DNA database, they also provide (for an additional charge) the ability to add what you know about your ancestry. DO THIS! Also, BE SURE to make your information public so your matches will know who they match and why. If they don't know those things, they usually won't bother to contact you.
A word of caution
Be aware that DNA testing can reveal things you or a close relative may not want to know. Even if you do want to know, it could be shocking.
There was a story about a woman who matched her father's Vietnamese daughter. The man didn't know the girl's mom was pregnant. She had never told him. Furthermore, he would have married her but was forced to quickly leave when the U.S. Army suddenly pulled out of the war.
He never knew of his "other" daughter by the Vietnamese girl he was in love with before he met his American daughter's mom. There was a happy reunion organized through an organization that helps Vietnamese children of unknown American fathers locate their American relatives.
Sometimes this can have the opposite effect. One man discovered his father's father was not biologically related. His dad was furious and wanted to sue the testing company for revealing a family "secret" he had wanted to remain a secret.
Whatever your goals are, make them clear to yourself before trying to find your answers online. If your goals aren't clear to you the answers to your questions will be difficult to find.