Understanding DNA Testing for Genealogy Research

Video Transcript

Hello, my name is Dewayne Jackson your host. In this presentation I’ll help you understand DNA Testing for Genealogy Research. Lately there has been a lot of discussion about this topic.

You may recall that this method of research is often referred to a Genetic Genealogy.

In 20012 Rachel Swarns of the New York Times wrote an article called, “Meet Your Cousin, the First Lady: A Family Story, Long Hidden. This article described the family connection between Michelle Obama and Joan Tribble, a white lady and retired bookkeeper from Atlanta, Georgia.

The article explained the DNA connection between the white families of Joan Tribble and black families of Michelle Obama, but it didn’t really explain how DNA was used to make this connection. In this presentation.  I’ll cover the 3 most popular categories of DNA testing, and I’ll explain how DNA connected Mrs, Obama with Mrs. Tribble. So, let’s get started. First, there are Autosomal DNA tests that provide a breakdown of all the ethnic populations that make up your DNA. Next, there are those that check for Mitochondrial DNA (mtDNA). The important thing for you to know about mtDNA is that it’s the type of DNA used to check your mother’s direct female lineage.  The 3rd and last type of DNA test that we’ll discuss today is the type that checks for Y-DNA. This type of DNA is used to trace your father’s direct male lineage.

Now, let me explain the difference between mtDNA and Y-DNA. Women only inherit and pass down mtDNA. Men inherit both Y-DNA and mtDNA, but men only pass down Y-DNA to their male children. For example, the mtDNA that’s inside me came from my mom.  My mom inherited a copy of this same mtDNA from her mother. My mom’s grandmother got her mtDNA from her mother.  I can keep going like this for my mom’s direct female lineage for hundreds and thousands of years. The way genetics work, I can’t pass down mtDNA to my children, but I can pass down the Y-DNA that’s inside me to my sons.

mtDNA or Y-DNA tests results only provide checks one direct lineage. Autosomal DNA Testing used to determine Ethnic populations provide results from across all of your lineages. For example, we all have 16 great great grandparents. Well, I have inherited unique DNA from all 16 of my great great grandparents and so have you. Autosomal DNA test, provides results from all 16 lineages, not just one lineage as seen with mtDNA or Y-DNA.

In the New York Times article, Mrs. Obama and Mrs. Tribble had a common ancestor named Henry Wells Shield. What DNA test do you think was used to confirm their connection with Henry Shields? The Answer is those used for Y-DNA testing.  Remember, women inherit mtDNA only from their mothers and men inherit Y-DNA only from their fathers. So, why wasn’t the answer to this question mtDNA? Don’t let the fact that Mrs. Obama and Mrs Tribble are women confuse you.  Neither one of them have Y-DNA. Their Ancestor, Henry Shields, however is a man and he only passed down Y-DNA, so how was this connection made?  The researchers had to get a male relative of Mrs. Obama and Mrs. Tribble to take the DNA test. So that’s how the DNA connection was made between the two families.

Well, I hope this topic of conversation as interesting for you as it was for me. This concludes my presentation. Thank you for viewing, and I wish you much success with your genealogy research.

Related Links

NewYorkTimes.com- Meet your cousin, the first lady: a family story, long hidden.

Dewayne Jackson’s DNA Test Results

What is Autosomal DNA?

What are Haplogroups?

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