By Dexter Montgomery

DNA testing for Genealogy, called Genetic Genealogy, is a powerful new tool, which is used in conjunction with family history research. This new tool provides new information, often information that cannot be uncovered from other sources.

DNA testing can:

• Determine if two people are related

• Determine if two people descended from the same ancestor

• Confirm your family tree

• Find out if others with your surname are related

• Prove your research

• Prove or disprove a research theory

• Find others to whom you are related

• Get clues about your ethnic origin

• Confirm a suspected ancestral adoption

• Provide clues to find the Ancestral village

• Determine the points of origin for a surname

DNA testing for Genealogy is Not a substitute for family history research. It is a tool to be used in conjunction with family history research. There are two basic types of DNA tests available for Genealogy: Y DNA Tests and mtDNA Tests.

The Y DNA test are only available for males, since the test involves testing a small portion of the Y chromosome, which is passed from father to son. Males have both an X and a Y chromosome. They receive the X chromosome from their mother, and the Y chromosome from their father. Females have two X chromosomes, one each from their father and mother.

Both males and females inherit mtDNA from their mothers. Testing mtDNA provides information about the direct female line of the person, which would be their mother, their mother’s mother, and so forth. MtDNA testing provides information about the original ethnic origin of your direct female ancestral line. The result of the mtDNA test would tell you which of the original daughters of Eve was your ancestor. MtDNA testing can also be applied to your genealogy research. An example of utilizing mtDNA testing for genealogy would be where an ancestor had two wives, and multiple daughters, and you want to determine which daughters had which mother. In this case, you would need to find direct descent female descendents of the daughters, and test them. Lets assume that Daughter 1 is documented with Mother A, and Daughter 4 is documented with Mother B. You are uncertain of the mother for Daughters 2 and 3. You would find female descendents of the daughters, in the direct female line, and test 1 descendent of each of the 4 daughters. The descendents of Daughter 1 and Daughter 4 should have different results, and depending on which of these results the descendents of Daughter 2 and 3 match, tells you whom the mother was of Daughters 2 and 3.

Because the Y chromosome typically follows surnames, there is a much wider range of applications for Y DNA testing, and a much broader spectrum of problems which can be solved, and information that can be acquired. Therefore, the balance of this article will focus on Y DNA testing.

Scientists have discovered a small portion of the Y chromosome is passed from father to son. It is located in the region called Junk DNA, and is not involved in determining our personal characteristics. Locations in this section of the Y chromosome are called Markers, and these Markers change at a rate of about once every 500 generations per Marker. When these locations, or Markers, are tested, the result is a numerical score for each Marker, reflecting a count of the proteins found. Below are some example results:

14 22 14 10 13 14 11 14 11 9 11 25
15 23 15 10 15 16 13 13 11 14 12 30 16 8 9 11 11 26 15 20 29 12 12 15 17
13 23 14 10 13 14 11 14 12 12 11 28 14 8 9 8 11 23 15 20 28 13 15 16 17

The first line of results illustrates the results of a 12 Marker Y DNA test. The next two lines are an example of a 25 Marker Y DNA test results.

The value of DNA testing comes in to play when comparing results of two or more males. By comparing the three (3) results shown above, we can determine that these people are not related in a genealogical time frame. None of the results match each other.

In the example below, we have the Y DNA test results for two people, who wanted to determine if they were related, and therefore had a common ancestor.

13 25 15 11 11 11 12 12 10 13 11 31 17 9 10 11 11 23 14 20 33 14 16 16 17
13 25 15 11 11 11 12 12 10 13 11 31 17 9 10 11 11 23 14 20 33 14 16 16 17

As you can see, the results match. This match is called a 25/25 match, since all 25 markers match between the two results.

In the example below, which is a 24/25 match, the two people are related, but most likely at a more distant time. In the example below, for the 24^th marker, one person has a 16, and one person has a 15. A mutation, or change, has occurred for this marker.

13 25 15 11 11 11 12 12 10 13 11 31 17 9 10 11 11 23 14 20 33 14 16 16 17
13 25 15 11 11 11 12 12 10 13 11 31 17 9 10 11 11 23 14 20 33 14 16 15 17

Since the Y chromosome is passed from father to son, the male direct line of descent must be followed when considering test candidates. Since females cannot participate, they often ask a direct descent male relative to participate.

The first step to utilizing DNA testing for Genealogy is to determine your objectives. What do you want to achieve? What is the research problem which you want to solve or for which you want to discover clues? Do you want to confirm your research, or determine the points of origin for your surname? Objectives are dependent upon your specific family history situation, and what you want to achieve.

The second step is to determine whom to test. Whom you test, and which test you select, depends on the objectives of your testing.

Below are some example objectives, a description of the situation, and whom you would select to test.

Case I:
Objective: Confirm research
Situation: You have only been able to find limited documentation that connects 3 sons to Epha.
Testing: Y DNA testing can be used to confirm your research. Test 1 descendent of each of the 3 sons. Their Y DNA test results should match or be a close match. A match is 12/12 or 25/25. A close match would be 11/12, 23/25 or 24/25. It is important to note that the testing results alone will not say that the Father is Epha. The test results combined with your family history research confirms your research. The test results without the family history research simply says that the people are related, and had a common ancestor, and an approximate time frame of the common ancestor. The test results alone do not identify the common ancestor. Identifying the common ancestor is the role of the family history research.

Case II
Objective: Confirm suspected Adoption
Situation: From your family history research, it "appears" that Epha took in a neighbor’s son and the son took on Epha’s surname. It is possible that the son was born in a different village to Epha’s wife, and you just haven’t found the entry.
Testing: Test one male descendent of one of Epha’s documented sons, and a male descendent of the suspected adopted son. If they match, or are a close match, they both had a common ancestor. If they do not match, then your theory is confirmed. It is important to note that the Y DNA test does not identify the common ancestor. If Epha took in a son of one of his male relatives, such as his brother, then the results of the descendents would match, even though they are not both Epha’s sons.

Case III
Objective: Determine if the two families with the same surname are related
Situation: You have found another family with the same surname, whose ancestors also came from the same village. You want to find out if they are related.
Testing: Test one direct descent male from each line. If they match, or are a close match, they are related.

Y DNA testing has many applications, depending on the situation, and is a powerful tool which is used in conjunction with family history research. Y DNA testing alone will not:

• Identify the specific common ancestor

• Identify where the ancestor lived

• Provide a name for the ancestor

Y DNA testing is frequently used in Surname Projects. Surname Projects involve testing one or two males from each identified Line of a surname, to determine which Lines are related, and therefore have a common ancestor. Surname Projects will also identify the number of origins for a Surname. In addition, Surname Projects often provide clues for further family history research and locations for research, and save people time.

The largest commercial testing company providing Genetic Genealogy testing services is Family Tree DNA, located in Houston, Texas. Family Tree DNA offers a wide variety of DNA tests for genealogy, at very affordable prices. All DNA tests from Family Tree DNA include lifetime matching in their large data base of results.

Family Tree DNA also has a unique set of tools available to assist in managing a Surname Project. These tools make is easy to manage a project, and saves the Project Manager a significant amount of time. These tools also enable some one with no prior experience to start and effectively manage a Surname Project.