This data is shared under a Attribution-NonCommercial-ShareAlike CC license. You are free to share and use the information for non-commercial purposes, as long as you give proper attribution and release anything you create under the same license.
For a summary of all Shared cM Project posts, see “The Shared cM Project.”
For reference, here are all posts for the Shared cM Project:
Older Posts:
[EDIT – June 26, 2016: An updated chart and detailed histograms are now available and should be utilized. See: “Update to the Shared cM Project.”]
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As you might recall, a few months ago I sent out a call (“Collecting Sharing Information for Known Relationships“) for information about the amount of DNA shared by people having a known genealogical relationship. I was hoping to get a better picture of the ranges of the amount of DNA shared by people in these relationships (through about the third cousin range). The incredibly generous genetic genealogy community responded by submitting data bout more than 6,000 relationships!
I posted information a few weeks ago (“Collecting Sharing Information for Known Relationships – Part II“), but today I have an update.
This data is shared under a Attribution-NonCommercial-ShareAlike CC license. You are free to share and use the information for non-commercial purposes, as long as you give proper attribution and release anything you create under the same license.
If you’ve researched (or need to research!) in New York, if you’re interested in DNA, or really if you’re interested in genealogy in general, won’t want to miss the 2015 New York State Family History Conference being held in Syracuse, New York on September 17-19, 2015!
The Second New York State Family History conference is a collaboration between the Central New York Genealogical Society and the New York Genealogical and Biographical Society, and is one of the Federation of Genealogical Societies’ regional conferences.
The 2015 NYSFHC Conference will be three days long and consist of three simultaneous lecture tracks and even more exhibitors than last year! The Federation of Genealogical Societies is sponsoring the first day of the conference. At present, other conference sponsors include the Capital District Genealogical Society, FamilySearch, findmypast.com, the New England Historic Genealogical Society, the New York State Library and Archives and the William G. Pomeroy Foundation.
Heritage Books, a leader in the world of genealogy publication for four decades, announces the 2nd Annual Heritage Books Genealogy Conference and Cruise, departing from Ft. Lauderdale, Florida on October 18, 2015 and returning on October 28th!
Interested in DNA?
This year’s cruise is focused on using the newest tool for your genealogical research, DNA testing. Are you a DNA newbie? No problem, with more than 20 different genetic genealogy presentations, this conference will take you all the way from complete novice to an intermediate user ready to add DNA to your genealogy toolbox. Are you well-versed in genetic genealogy? Come and learn the latest tips and tricks to enhance your DNA knowledge.
In addition to a full slate of presentations, one-on-one consultations, and several group sessions, conference attendees and passengers will have plenty of time to enjoy the sights, sounds, and flavors of the Caribbean as the Coral Princess makes stops in the topical destinations of Aruba, Cartagena, Grand Cayman, and even makes a partial transit of the unparalleled Panama Canal. You can find the full schedule for this amazing trip here.
I’ve recently noted a trend among genealogists to discount unexpected (or unwanted?) DNA test results in order to make the results fit an existing hypothesis, instead of properly re-evaluating the hypothesis in light of the new DNA evidence. (This is NOT made in reference to any specific person, post, or question; it is rather something I’ve been mulling over for some time).
Let’s take third cousins as an example. According to Family Tree DNA’s FAQ, you will share detectable DNA with approximately 90% of your third cousins under FTDNA’s threshold. According to AncestryDNA’s help page (see “Should other family members get tested?”), you will share detectable DNA with 98% of your third cousins under AncestryDNA’s threshold. In other words, if you have 100 third cousins and they all get tested (how’d you do that?), you will share DNA with 98 of them.
As you might recall, a few weeks ago I sent out a call for information about the amount of DNA shared by people having a known genealogical relationship. I was hoping to get a better picture of the ranges of the amount of DNA shared by people in these relationships (through about the third cousin range). Although people like Tim Janzen have gathered this type of data and so kindly made it available for everyone, I felt like more data was needed.
What is the range of cMs shared by third cousins? What does the distribution within that range look like? Does the longest segment factor into that at all? If so, how?
These are the types of questions I wanted to examine. And to entice submissions, I offered a free Family Finder kit to one lucky person that submitted data prior to April 1, 2015.
The following is a guest post by Ann Turner, founder of the of the GENEALOGY-DNA mailing list at RootsWeb and co-author (with Megan Smolenyak) of “Trace Your Roots with DNA: Using Genetic Tests to Explore Your Family Tree.” Thank you Ann for this terrific post!
Genetic genealogists use autosomal DNA testing to locate people who share some DNA, enough to point to a relationship in a genealogical time frame. We’re not impressed by accidental matches that occur simply because all humans share 99.9% of their DNA. We want to be confident that the shared DNA segment is Identical by Descent (IBD) from a particular common ancestor, one who lived some number of generations in the past.
Two practical difficulties stand in the way of definitive confirmation. One is that our pedigrees are not complete, and we cannot test every link in the chain to prove that the segment traveled down the pathway we’ve identified through the paper trail. Indeed, as more data accumulates we frequently discover that a match we attributed to one ancestor must have come through an entirely different line.
[Read on to learn how you could win THREE hours of FREE consultation and research from me for registering in this course before March 21st!]For the next two Saturdays, March 21st and 28th, I will be spending some quality time with genetic genealogists! My new course entitled “(Finally!) Understanding Autosomal DNA” is a four session course designed to educate genealogists on all the ins and outs of autosomal DNA.
The course is being offered through the wonderful new Virtual Institute of Genealogical Research. The Virtual Institute offers courses on a wide variety of genealogical subjects, providing vigorous year-round education for the genealogical community using a virtual platform.
The four courses will provide attendees with the fundamentals of autosomal DNA, third-party tools, and triangulation. Here is the course schedule (all times U.S. Eastern):
21 March 2015
28 March 2015