This article is the third article in a series about the genetic genealogy workshop presented by the Fort Worth Genealogical Society. The second article was entitled, “Speaker explains genetic inheritance and genealogy” and the first article was “Genetic genealogy another tool in ancestry research.”
Jane Buck gave a thorough explanation of genetic genealogy at the “DNA for Genealogists” workshop presented by the Fort Worth Genealogical Society.
Buck has a background in biology and presented the workshop on behalf of Family Tree DNA.
She explained there are four major types of DNA, and three of them are most often used in genetic genealogy: Y-DNA, mtDNA, and autosomal DNA.
The most common DNA genealogists test for is Y-DNA, which is only passed on through males.
The father’s sperm fertilizes the mother’s egg and the sperm will contribute either an X or a Y chromosome to determine the sex of the child. A female will have two X chromosomes because it receives one from each parent. A male will have one X chromosome from the mother and one Y chromosome from the father.
Only males can take the Y-DNA test
Because Y-DNA is passed on by fathers to sons only, a Y-DNA test must be taken by a male subject. If a genealogist wanted to follow the Y-DNA of both sides of his or her parents, then four different males would each have to take a Y-DNA test.
If the genealogist is a male, he can take the test himself and follow his Y-DNA back in time. When the report comes back it can show where the earliest ancestors in that surname line came from, migration patterns, and more. If the genealogist is female, she must get her brother, father, paternal uncle, paternal cousin, etc. with the same surname and lineage to take the test for her.
If the genealogist wanted to trace the Y-DNA of the paternal grandmother to cover both sides of the father’s family, then the paternal grandmother’s brother or the brother’s male children must take the test.
It is possible for the genealogist to follow the Y-DNA of both sides of the mother’s family. To follow the mother’s paternal line, the mother’s father would take the test. If the mother’s father is no longer living, then the mother’s brother or male nephews with the mother’s maiden name from the same Y-DNA line as her father would have to take the test.
In order to trace the mother’s maternal Y-DNA, the genealogist’s maternal grandmother’s brother or male nephews would have to take the test.
The fictitious case of genealogist Bob Jones
Bob Jones wants to trace the Y-DNA of the maternal and paternal lines of each of his parents. His paternal lines are Jones and Smith. His maternal lines are Miller and Johnson. So, if Bob Jones is the genealogist, he can take his own Y-DNA test to follow the Jones line.
If the genealogist is Janet Jones, she must get her brother Bob or her father to take the test. This would follow the genealogist’s surname and follow the genealogist’s paternal line.
So, for Bob Jones to follow his paternal grandmother Betty Smith’s Y-DNA, Bob would have to ask James Smith, his grandmother Betty’s brother, to take the test, to follow the Smith line. He could also find some male Smith cousins to take the test. This would represent Bob’s two paternal grandparents.
In order for Bob Jones to follow both sides of his mother’s family, he would start with his maternal grandfather, Mark Miller, to follow the Miller line. If his grandfather is no longer living, then Bob’s uncle, Frank Miller, could take test, or any of Bob’s male Miller cousins.
If Bob Jones wants to follow his mother’s maternal Y-DNA, he needs to talk to his grandmother, Sarah Johnson, who married his grandfather, Mark Miller. Bob would need his grandmother Johnson’s brother or any male Johnson cousins to take the test.
These four tests would cover Bob’s four major lines, Jones, Smith, Miller, and Johnson and would represent his four grandparents.
Once the tests are in the Family Tree database, the genealogist’s information is compared with the rest of the database. If common ancestors are found, Family Tree DNA will alert the genealogist to say there is a match and then both parties can contact each other and exchange information and expand their family’s ancestry knowledge.
The challenge for genealogists can be finding enough male relatives to take the tests. A female genealogist who is an only child has to rely on finding uncles and cousins for every test. If a genealogist does not know one line of the family very well it can be difficult to reach everyone while everyone is still living.
Family Tree DNA was founded in 2000 and was the first company to develop commercial applications for genetic genealogy. Jane Buck began her genealogy hobby in 2005 and in 2010 joined Family Tree DNA to lead their customer service department. While Buck is no longer with the company and now works in environmental consulting, she still speaks to groups on behalf of Family Tree DNA.
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