Article | Charts: Sharon Clayton
Clan member Allan Thomas, who lives in New Brunswick, is an artisan who turns heirloom cutlery into jewelry. This article started out to tell the stories behind Allan’s Let’s Spoon Jewellry creations: https://www.facebook.com/allan.thomas.5
After discovering that Allan shares generous DNA segments in common with several members of Clan MacRae of Canada, my addiction to genetic genealogy got the better of me! I still want to write an article about Allan’s business, but that article won’t be published until the spring.
For those who are not familiar with genetic genealogy research, here is a general overview – After Allan received his DNA testing kit in the mail from Ancestry, he spit about a teaspoon of saliva into a tiny vial. It may surprise you to learn that Americans can mail their saliva to Texas, but the US government does not allow Canadians to mail our spit across the border, so we mail our kits to an address in Ireland.
After Allan’s DNA sample was batch-processed, Ancestry DNA sent him an email that provided access to his estimated ethnicity percentages, and a match list of his DNA cousins. Allan then downloaded his Ancestry DNA digital data file to his computer, and uploaded it to Gedmatch.com, a third-party company that accepts transfers of autosomal DNA data files from each of the companies that sells DNA test kits: Ancestry DNA, Family Tree DNA, 23andMe, My Heritage and Living DNA.
Almost every day, I spend some time playing with Gedmatch’s chromosome browser comparison tool. This is just one of several advanced DNA analysis tools available via Gedmatch’s optional Tier 1 subscription service, which costs $10 USD for each month it is used.
While checking out Allan’s Gedmatch DNA cousins, I noticed that Clan MacRae of Canada members Deb Gemmell, Joanne Monahan and Owen MacRae were all on Allan’s match list.
On the graphic displays on pages 10 and 11 of chromosome browser comparisons, each of the coloured horizontal bars represent gene segments that Allan shares with each Clan MacRae cousin on his match list. The start and stop numbers for each segment identify where each segment begins and ends. I have added explanatory comments on chromosomes 12 and 13, where Allan’s gene segments are shared with more than one Clan member.
LEGEND – Gene segments are measured in centimorgans – our closest DNA matches share thousands of centimorgans (cMs) with us. People who share only 7 centimorgans are very distant cousins.
The common ancestors we share with our distant cousins probably lived four – seven generations ago.
Endogamous relationships occur when populations are geographically isolated from each other. In some cultures, there is a preference for marrying within a religion, ethnicity or language group, and also to consolidate wealth and power, as royal families have done for centuries. Clan MacRae’s endogamy has resulted in gene segments being passed down from paternal and maternal ancestors who were related to each other. Endogamy can be considered either a curse or a blessing. In this case, these endogamous segments might help us identify the person or married couple who are each DNA cousin’s family tree.
The Generations matrix chart below provides an estimate of how many generations back to look for the most recent common ancestor (MRCA) who passed down these MacRae gene segments. Because some MacRae ancestors married 1st to more distant cousins over several generations, common ancestors of these DNA cousins might have lived even longer ago than the chart suggests.
The Autosomal matrix chart below shows us how many centimorgans (cMs) each cousin shares with each of the others. On the Gedmatch site, the little green trees in the Gedcom columns are clickable. When we click on a tree, Gedmatch takes us to a family tree chart that each DNA cousin has attached to his/her Gedmatch kit.
Now that we have evidence that each of these MacRae descendants inherited at least one gene segment from someone on Allan Thomas’ family tree.
I hope several of these MacRae DNA cousins will be willing to do collaborative research that will eventually identify the ancestor who passed down their shared gene segments.
Watch for a follow up story in the Spring 2022 issue of Kintail.