Everything you need to know about using DNA to trace your family history

DNA profiling to trace your family history has become a household phrase during the past 2 decades or so. TV shows about using DNA have fed into this need to find one’s DNA pattern.

Now using DNA to trace your family history is not just a science fiction, but it actually is a real thing. Advances in Science and technology have made it easier to get an idea of your origins or your family history. Dozens of Biotech companies now offer to examine your DNA to help you learn more about your ancestry and trace your family history easily.

How Your DNA can Help You Trace Your Family History?

Your DNA tells a lot about you and your family history. It lets you know what health conditions you are and are not susceptible to determine the color of your eyes and hair, your ability to learn certain things easily (like math), and even your ability to smell or taste certain things. It also tells you about your family history or ancestors, since they are the ones who passed down their DNA to you.

You have a 50% chance of inheriting any particular DNA trait from either parent. This means that if one parent carries the DNA for brown eyes and one carries the DNA for blue eyes, you have a 50% chance of inheriting either one. If you just happened to get the blue eye DNA and your sister got the brown eye DNA, that just means the genetic coin flip landed on one side for you and one side for her.

Your parents likewise each had a 50% chance of inheriting different types of DNA from each of their parents. Whatever they inherited, they have a 50% chance of handing down to you. This is how physical features and other family traits change (or sometimes stay the same) through the generations.

Your genes are located in your DNA. The more genes you share with someone, the closer you are related to them. If you aren’t sure of your relationship to someone, a DNA test done by both of you will tell you how you’re related. For example, full siblings share around 50% of their genes. Half-siblings share only about 25%. You also share about 25% with your aunts and uncles. First cousins share around 12%, second cousins share around 3%, and so on down the ancestral line.

However, relationships to living relatives are not all DNA research can reveal. It all depends on what type of DNA you have tested.

It is a well-known fact that humans share about 99.9 percent of the same sequence of DNA. Only about 0.1 percent of the sequence is different among various groups of humans. Regional populations of humans tend to share many of the same genetic markers. By comparing your DNA to a database filled with other subjects’ DNA sequences, genetic testing companies can give you an idea of where your ancestors came from.

It’s important to note that the information you get from a DNA genealogy test is general and probabilistic. That means the answers are based on statistical probabilities they aren’t hard and fast facts. While some genetic markers may be commonly found in one particular population, that doesn’t mean they’re unique to that people. It just means you’re statistically more likely to be related to those people than other groups.

But before you fork over more than $100 for such a test, you need to know answers to these question: Can a DNA test really tell me about where I come from? How do these tests work? And can they be wrong?


There are three different types of DNA, which include Autosomal DNA, mtDNA and Y-DNA. Each type tells something a little bit different about oneself and one’s heritage.

1. Autosomal DNA: offers the most extensive answers. It provides both kinship and medical results. It traces back six or possibly seven generations. Once tested, the testing company can identify other people already in its database, called cousins, who share long strings of matching DNA. (The matches are labeled cousins because somewhere back in the lineage, the two people came from a common couple pairing.) In addition to lineage, this type of DNA also can identify physical traits and medical predispositions.

2. mtDNA (mitochondrial DNA):  offers deep ancestry information through the female line. Mitochondria are found in the cytoplasm of human cells, and while a mother passes it to every child, only daughters pass it on to the next generation. The mutation rate for mtDNA is only every 450 years or 22 generations, so having one person in a family tested is usually enough. Information found with a test for mtDNA would be able to tell a person what geographic area in which the matrilineal family line originated. It also is possible to find out what other family lines stemmed from the same origin and branched out elsewhere.

3. Y-DNA:  offers information passed only through males. It is the DNA on the Y-chromosome. Similar to mtDNA, Y-DNA also has a slow mutation rate. The mutation rate is about 150 to 200 years, so again, having one person tested in a family line is often enough to gather the results needed. Information about the origins of the patrilineal line can be found with a test for Y-DNA.

If you’re submitting just your own DNA, you’ll get results that will tell you more about your genetic makeup. If you’re male, you can perform a Y-DNA test to find out where your paternal line comes from (women lack the Y chromosome ). Men and women can perform a mitochondrial DNA (or mtDNA) test to learn about where their maternal line comes from. You can even determine if you’re related to someone specific if you’re able to submit DNA samples from you and the other person.

Some companies offer different versions of the Y-DNA and mtDNA tests. Usually this means that one test uses more genetic markers than the other, giving you a more accurate glimpse at your family background. If you’re trying to find out more about your particular surname, you’ll need to order a test that looks at more markers than a general ancestry test. You may find some companies offering package deals in which you can order both a Y-DNA and mtDNA test. Other DNA tests can tell you if you’re related to a specific person,both people need to take the test.

As companies build out their databases, they uncover more information about human populations. The genetic population you belong to might change. This doesn’t mean your DNA changes. It just means that as we learn more about our ancestors we refine our definitions and classifications.

How to Get a DNA Test for Research

Commercial tests are available for each DNA type. At the moment, five companies offer commercial DNA testing: FamilyTreeDNA, DNA.Ancestry.com, 23andMe.com, Nat Geo and DNA Tribes. All of the companies offer some type of ethnicity report, but only 23andMe will give a chromosomal view, showing physical traits and medical predispositions.

The first thing you should do is research the company. Make sure the company has a good reputation. Each company relies on its own proprietary database of DNA information. The larger the database is, the more accurate your results will be. And a respected company is more likely to stick around long after you take your test. Some companies will even send you updated information about your results as they refine their databases.

Worried about a blood test? The tests are simple and painless. Taking these tests is straightforward. A person swipes the inside of his or her cheek for a saliva sample, which is sent to a lab. There, the DNA is extracted, amplified, and analyzed. It is then compared to and matched with DNA samples from a reference database of haplotypes – a set of closely linked genes or DNA polymorphisms – that have been identified in specific populations. If a person’s DNA sequences match certain sequences in the database, the information can be used to determine the populations with which that person shares maternal or paternal ancestry.

Getting a test is as simple as ordering the right test kit from the company you have chosen. The company will ship the test to you. Once you take the test, you can send the sample to the company for analysis.

Where do they post DNA Test Result

Once the company you’ve chosen completes the analysis of your DNA, it will send you the results. Some companies will give you the option including your results in a special database. If other customers have results that match yours, the company can contact you and the other people to let them know of the match. A match means that you share an ancestor with the other customer, though it’s impossible to determine how far back that ancestor might be from the results alone.

By getting in touch with people who match your results, you may be able to fill in the gaps in your family’s history. You may also discover distant cousins who split off from your branch of the family many decades ago. Your results will help the company refine its classifications each customer’s data adds to the bigger picture.

Some testing companies create profile pages for customers on their Web sites which is like a social networking site. This can help you get in touch with other customers of that company who have similar DNA results to your own.

There are also web sites where you can create an account and post your results. One may wish to search their surname- many surnames have Web sites dedicated for genealogical research. Or they can post the results to their own personal site.Or they can even post the haplogroup they belong to, but haplogroups are very general, they just define genetic populations. A genetic population isn’t necessarily linked to a particular ethnicity, culture or even geography. And the classifications for haplogroups for Y-DNA results are different than those for mtDNA results.

It’s only by looking for marker matches that you’ll start to uncover possible relatives. If you and another person have several markers that match, there’s a chance you may be related. The more marker matches you have, the more likely you share an ancestor within a few generations.

DNA Genealogy Projects

There are plenty of genealogy projects currently which tells about your family history . They range from regional to global in scope. Some are meant to give a big picture glimpse of how people migrated from one region to another over millennia -these are more anthropological than genealogical in nature. Others help people get in touch with fellow genealogists to solve mysteries and connect to family members who may be separated by geography and generations alike.

One of the largest projects is the Genographic Project spearheaded by National Geographic. You can participate in the Genographic Project by purchasing a test, which costs around $100 and submitting your sample to the project. This project does not help you find out who your great-great-grandfather was. But instead, the project’s  main aim is to map the migratory patterns of human history. It’s about as big a picture as you can get.

The USGenWeb Project is a volunteer organization dedicated to helping citizens of the United States research their family backgrounds. The project has links to each state project. Within the state project site, you’ll find links to resources that might help you find out more about your family. In many cases, the links will tell you where you need to go to see official documents that have your family’s information on them. You’ll still need to do some legwork to fill in the gaps, but the projects resources can give you a good place to start.

The WorldGenWeb Project has similar goals but on a global scale. It contains links to regional genealogical project Web sites. Volunteers can elect to oversee a particular region. It becomes that volunteer’s duty to gather research resources and create forums for members to connect with one another and discuss family histories.

Many surnames have their own DNA projects. Most of these projects began as personal projects that grew over time and merged with other projects for the same surname.

Keep in mind that these projects are meant to help you in your search for information about your family. They do not present your complete family history through a single search query. You’ll most likely need to do additional research and contact distant relatives to build out a full history. If you haven’t used DNA to explore your genealogy, you should. It is a wonderful replacement to the traditional research methods you are using. Even better, it has the potential to unlock genealogical mysteries when the paper trail ends. Use it, and discover your true roots.