Using mtDNA for Genealogy: A Case Study – Introduction

You may have heard that DNA testing can be seen as “fishing trips”, where you test, see who you match and then try to figure out who your common ancestor is, and “hunting trips” where you seek out particular people to test to compare against your DNA. You may have also heard that Mitochondrial DNA (mtDNA) is pretty useless for genealogy. Well, it is often useless for “fishing trips”, but in this series of posts, I’m going to demonstrate how it can be quite useful for a “hunting trip”.  To do this, I’m going to share how I used mtDNA to try to answer the question “Who were Charlotte Richardson’s parents?”

I did this research in 2016 and presented my findings at the British Isles Family History Society of Greater Ottawa (BIFHSGO) annual conference in September 2016, on a panel called “Making Connections: Adventures in Genetic Genealogy”. This is an adaptation of that presentation.

Who was Charlotte Richardson?

Charlotte Richardson was my 5^th great grandmother, along my maternal line. While I’m fortunate to be able to go back 7 generations and 240 years on this line, I was stuck on Charlotte. And you know how it is…. we always want to get further back!

Charlotte was born in 1776 in New Brunswick or Prince Edward Island (now Canada), depending on which census you believe. On the 1851 NB census she was said to have been born there. The 1861 census has her birthplace as PEI. She married Richard Dobson when she was 18. Richard was born in 1769 in Yorkshire, England. In 1773, when Richard was 4, he and his family were among the over 1,000 immigrants from Yorkshire who settled in the Chignecto Isthmus (the neck of land that joins New Brunswick and Nova Scotia) between 1772 and 1775. Richard and Charlotte settled in Cape Tormentine, NB where they raised 12 children.

You can read more about Charlotte, including the conclusions to this research, in my last blog post, 52 Ancestors #3: Charlotte Richardson (1776-aft.1861). If you’d rather not have spoilers on how this research turned out, you may want to wait until the series is over to read that post.

Possible Parents

At the time I started this research, there were 152 Public Member Trees on Ancestry that had Charlotte Richardson, wife of Richard Dobson. Of those:

• 94 trees had unknown parents.
• 51 had her parents as John Christopher Richardson and Mary Flintoff
• 6 had her parents as British Army Officer Richardson and Unknown

There was also one tree with completely different parents, born about 1850.  Since they would have born 75 years after their daughter, I went out on a limb and ignored that as a possibility.

Of the two plausible theories, neither had much in the way of solid evidence to back them up:

• Theory 1: Charlotte was the daughter of John Christopher Richardson & Mary Flintoff. John & Mary were Yorkshire immigrants who arrived in Canada about the same time as the Dobsons. They settled in Sackville, which was not far from where Richard & Charlotte later lived. John and Mary did have a daughter named Charlotte, but one source, a history of Sackville published in 1933, says that she married someone named Horton. Other sources say she married Richard Dobson. But none of these are primary sources.
• Theory 2: One of the researchers of the Dobsons has a letter from 1941 that says that Charlotte was the daughter of a British Army Officer, whose regiment was then stationed at Charlottetown, PEI. Obviously it would be hard to test this theory directly with little else known. But, there could be an indirect way.
• Theory 2a: There was also a Barbara Ann Richardson, born in Charlottetown in 1782 (6 years after Charlotte), who married James Ingraham and settled in Cape Breton, Nova Scotia. Some people have speculated that they might have been sisters, due to the strong links between Charlotte’s family and Barbara Ann’s family. Two of Charlotte’s sons married two of Barbara Ann’s daughters.

How could mtDNA help?

Mitochondrial DNA is passed along the female line. Both males and females carry their mother’s mtDNA, but only women pass it on to their children. Since I’m a direct female-line descendant of Charlotte Richardson, I carry her mtDNA. In order to test the two theories, I needed to find people to test in order to compare their mitochondrial DNA with mine. Here was my basic research plan, which I’ll go through in more detail in subsequent posts:

• Step 1 – Identify potential matches
• Step 2 – Contact potential matches
• Step 3 – Test one person from each line
• Step 4 – Compare results

Possible outcomes

There were 4 possible outcomes to this comparison:

1. If I matched someone on Mary Flintoff’s line, it would confirm that Charlotte was the daughter of John Christopher Richardson and Mary Flintoff.
2. If I matched someone on Barbara Richardson’s line, it would confirm that they were sisters, but I still wouldn’t know who their parents were. I would, however, know that I was looking for someone who lived on Prince Edward Island between 1776, when Charlotte was born, and 1782, when Barbara was born.
3. If I matched both, it would confirm that Charlotte and Barbara were sisters AND they were both the daughters of John Richardson & Mary Flintoff.
4. Or of course, I could match neither. In that case, not only would Charlotte’s parents be unknown, I would have no evidence supporting the theory that Charlotte and Barbara were sisters. This could be because they weren’t, or because one or both trees were wrong, either due to misattributed parents or a non-parental event.

In the next post, I’ll provide details on how I identified potential matches. Meanwhile, I’d love to hear your experiences with using mtDNA.