If you’re doing DNA tests for family history, you may see lots of predicted cousin matches: 2nd, 3rd, 4th, etc…..But what does that predicted genetic relationship actually mean? Learn about centimorgans, the powerful genetic genealogy unit of measure, and how it helps your research.
How DNA Tests Measure Genetic Relationships
When we are looking at genetic relationships, there are also many ways we can measure them. But ultimately, we want the testing company to tell us how likely it is that a particular individual shares a single, recent common ancestor with us. One factor in this calculation is to take into account the total amount of DNA we share with that match.
Currently, all the testing companies are reporting this sum in centimorgans (cMs). Every company reports to you the total number of shared cMs, as outlined below.
AncestryDNA: Click on the match to access the personal profile page for that match. In the second section, under Predicted Relationship, you will see the confidence level. To the right of the confidence level, you will see a grey circle with a little “i” in it. Clicking there will show you the total amount of shared cMs as well as how many pieces of DNA you share.
Family Tree DNA: On the main match page for your Family Finder results, you will see the total amount of shared cMs in the third column.
23andMe: You can see the percentage of shared DNA from the main DNA Relatives home page. To convert the percentage into centimorgans, just multiply your percentage by 68 (that will at least get you close). You can also see total shared cMs in the chromosome browser tool (go to Tools > DNA Relatives > DNA).
MyHeritageDNA: The total amount of shared DNA is shown on the main match page under the title Match Quality. MyHeritage also has a new DNA Match Review page. Click here to read more about that.
Centimorgan: A Genetic “Crystal Ball”
It is very tempting to think of a cM just like you would think of an inch or a centimeter, and for all practical purposes, that is okay. But it is actually much more complicated than that.
A cM is actually more like a crystal ball: it helps us predict how likely a piece of DNA looks exactly as it did a generation ago. This, in turn, helps us calculate how far back we should be looking for the common ancestor between two people.
But for our practical purposes, you can use the total amount of shared DNA, in combination with this chart compiled by Blaine Bettinger and the Shared cM Project, to better assess your genealogical relationship with your match based on your genetics.
To use the chart, take the total amount of shared DNA you have with a match, and look up that number in the chart to get an idea of what kind of genealogical relationship might best fit the genetics that you see. For example, if I share 69 cM with my match, we might be third cousins. But we might also be second cousins once or twice removed.
How do you figure out which one? Simply put: do genealogy research! It’s time to use traditional records and research skills to better understand the genetic clues in your family history mysteries.
My series of DNA quick reference guides can help you get the most out of your DNA tests for family history. I definitely recommend the value-priced bundle of all 10 guides. But I especially recommend the guides listed below if you’re to the point where you’re trying to understand what genetic relationships mean:
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I’m busy packing my bags getting ready to make the trip from California to London for my third appearance at Who Do You Think You Are? Live in London.
Here I am in last year’s experts panel
I’ll be teaching some of my favorite classes (sorry, they are already sold out, but I look forward to seeing those of you who have tickets there):
Friday 3/22 at 2:30 pm Ultimate Google Search Strategies
Saturday 3/23 at 11:00 Turn Your iPad (and Tablet Too!) into a Family History Powerhouse
If you don’t get a chance to attend my classes don’t fret, because I have a free ebook for you called 5 Fabulous Google Search Strategies for the Family Historianthat will jump-start your research. It’s available for free when you sign up for my free Genealogy Gems e-Newsletter.
One of the best parts about the event for me is meeting all of you! And this year that will be easier than ever. When I’m not teaching you can find me at the Family ChartMasters booth (#12)
There’s so much to look forward to at this years event. Whether you’re new to tracing your family tree or a seasoned researcher, it’s packed with genealogy experts, informative workshops, over 160 specialist exhibitors and celebrities from the UK television series to help you with your own family history search. Is it any wonder that Who To You Think You Are? Live made it on my 50 Family History Favorites list (which includes my top 5 conference picks!) Here the list in the brand new free Genealogy Gems Podcast Episode 151.
It is often said that “bigger is better” here in America, but in the case of family history conferences, the British have won the “super-sized” title. As an American genealogist, when I walk into the immense Olympia convention centre, I feel like a kid in a candy shop. Contained within those walls is more energy, more color (LOVE the hot pink carpeting!), more vendors and more genealogists than just about anywhere else. You certainly don’t have to have British roots to benefit from attending. This is my third year and I look forward to it as much as the first time.
So many of the Genealogy Gems Podcast’s 1 million downloads have been from the UK that it’s like “old home week” for me. Hope to see you there!
Got ancestors from England, Scotland, Wales or Northern Island? Check out these new UK genealogy records online: 1939 Register updates; newspapers; Scottish postal directories and local resources for Derbyshire and the city of York.
Featured Update: Additions to the 1939 Register online
Over 660,000 new records pertaining to empty, uninhabited addresses across England and Wales have been added to Findmypast’s unique and important online 1939 Register resource.
We asked Jim Shaughnessy at Findmypast how these records can help a researcher. “There are a few things that an empty address can tell you,” he responds. “Knowing the house you are looking for was an empty address in 1939 may help you to direct further research. As with other record sets, the occupations of the neighbors can give you an idea of the area (in terms of the largest local employer).”
The ability to search even vacant addresses “can also give you information about areas [later] destroyed by aerial bombing during the War (and during the extensive regeneration in the decades following),” writes Jim. “The Register was compiled September 1939; bombing began in 1940 and a lot of houses wouldn’t have been rebuilt, particularly in impoverished areas where we had bombsites for years and years afterwards. So from that you could look at how the War changed that area or that street: what doesn’t exist now but did pre-Blitz.”
Jim also pointed out that “Findmypast is the only site on which you can search by address on the 1911 census as well as the 1939 register, plus we have the largest collection of electoral rolls, also searchable by address. You can search by address and then build the entire picture of what your family did.”
In addition, Findmypast has added over 186,000 records to its collection, Sussex, Eastbourne Gazette Newspaper Notices. “This indexed collection includes names found in the paper’s family notices section (announcements of births, marriages, and deaths) as well as other reports on events such as divorces, murders, tragedies, shipwrecks, lynchings, and paternity cases. The newspaper reported on stories in Sussex, but also internationally.”
Derbyshire, England. Over 800 records have been added to Findmypast’s unique collection of Derbyshire Hospital Admissions and Deaths 1855-1913. “The collection now contains over 5,000 records taken from two different sources: Derbyshire Royal Infirmary, Deaths 1892 – 1912 and Victoria Memorial Cottage Hospital, Ashbourne Admissions 1899 – 1913,” states an announcement. “Each record includes a transcript produced by the Ancestral Archives of Derbyshire. Records can include the patient’s admission date, reason for admission, condition after admission, marital status, residence, rank or profession, date of discharge or death, and cause of death.” Looking for other Derbyshire ancestors? Click here to read about online Methodist records for Derbyshire.
York, England. A new Findmypast resource, The York Collection, includes nearly 300,000 genealogical records documenting over 600 years of residents of the city of York. A press release calls it “the largest online repository of historic City of York records in the world….Fully searchable transcripts of each original document are also included, enabling anyone to go online and search for their York ancestors by name, location, and date.”
The collection is comprised of a variety of fascinating documents, including hearth & window tax records (1665-1778); lists of apprentices and freemen (1272-1930); city of York trade directories; electoral registers (1832-1932), city of York school admission registers; city of York deeds registers (1718-1866); city of York militia & muster rolls (1509-1829), and city of York calendars of prisoners (1739-1851). This collection was published in partnership with Explore York.
Scotland Directories
A snippet from an 1820s post office directory for Aberdeen and vicinity. Image on Findmypast.com.
Over 180,000 new record images have been added to Findmypast.com’s collection of Scottish post office directories, now spanning 1774-1942. The collection has nearly 900 browse-only volumes of directories that offer descriptions of Scottish towns along with lists of residents by occupation and address.
Here’s a little background from Findmypast: “Post directories are an excellent source for family historians wanting to trace ancestors on a yearly basis. Directories allow you to fill in the gaps between the census records. They can also provide vital information about your ancestor’s residence, which can lead to the discovery of more records….Directories can add historical context to your ancestor’s story. Directories will give you a better understanding of where your ancestor lived, such as how many businesses were in the town, how many schools, what day was the market day, and how big was the town.”
“Directories may focus on a particular town or district or you can find national postal directories. The majority of post directories comprise a description of the place, along with lists of people by occupation. For example, you will find lists of magistrates, councillors, sheriffs, police officers, and merchants. It is important to remember that post directories are not complete lists of all the residents in the town or county. Also, many directories fail to include women.”
TIP: A browse-only collection of digitized Scottish post office directories for 1773-1991 is available to search for free online at the National Library of Scotland.
Start researching your English ancestors with this free two-part article series:
This isn’t a mess—it’s a pile of unprocessed records at an archive, and buried within may be clues about your family history. Eventually, these items may be filed away neatly for you to find. But how can you access them in the meantime? As an archivist who works in an...
Free Online Records at the Allen County Public Library Genealogy Center
If you’re looking for a wide array of free online genealogical records for your family history, look no further than then Allen County Public Library’s Genealogy Center in Fort Wayne, Indiana. It’s the second largest genealogy library in the country. In addition to the in-house collection, the Genealogy Center offers a vast amount of free digitized resources through their website and partnerships with other websites.
I invited Allison Singleton, Senior Librarian at the Allen County Public Library Genealogy Center in Fort Wayne, Indiana to the show. She is taking us on a tour of the website and sharing her tips and strategies for finding genealogy gems.
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MyHeritage.com is the place to make connections with relatives overseas, particularly with those who may still live in your ancestral homeland.