11 September 2021

DNA Painter's Shared cM Tool — Ranges, Probabilities, and Histograms

(Click on any image to view a larger version.)

Many genealogists are familiar with using the tools at DNA Painter to find clues to the possible relationship when the relationship is not known between two DNA test takers. The clues are based on how much DNA in centiMorgans (cM) the two share. The tools can also provide evidence to disprove or support a known relationship. Anyone who has worked with DNA for very long knows that what we “know” or “believe to be true” may be disproven by DNA evidence. Even when we think a relationship is known based on family memories, the conclusion is more sound with supporting DNA evidence.

The data displayed by the “The Shared cM Project 4.0 tool v4” at DNA Painter (https://dnapainter.com/tools/sharedcmv4) is a collaboration between Blaine T. Bettinger, Leah LaPerle Larkin, and Jonny Perl.

“The Shared cM Project 4.0 tool v4” provides three data elements for analysis of relationship possibilities based on the amount of autosomal DNA (atDNA) shared by two test takers:
  1. the average amount of atDNA shared and the range of values (low-to-high) reported by actual project participants,
  2. the probabilities (based on simulated data) for various relationship possibilities based on the amount of shared atDNA entered, and
  3. a histogram of the reported data for a given relationship as calculated from the Shared cM Project reported data1
Details are provided here for using these data elements on an example case where BJ04 shares 111.32 cM of DNA with DP5, known to be a first cousin twice removed (1c2r).

Using the Shared DNA amounts

Comparing the shared DNA between two people of a specific relationship is easily done using the chart at https://dnapainter.com/tools/sharedcmv4. Obtain the number of cMs shared by two test takers and determine if it falls within the range specified on the chart for the relationship believed to be shared by the two. This can be done by manually searching the chart for the known relationship box, then comparing the amount of DNA shared by the test takers to the range of values listed in the box.

Entering 111.32 into the tool highlights the blocks for many possible relationships (some shown in figure 1) that can share this amount of DNA. The 1c2r block is one of those highlighted. This block indicates 1c2r share an average of 221 cM, with the reported range being 33-471 cM.


Figure 1. Shared cM Tool on DNA Painter with only potential relationship blocks highlighted.


Using the Relationship Probabilities

Figure 2 illustrates the relationship probability display. The probabilities, displayed after entering a cM value in the “Filter” box, are best used to determine the most likely place to begin looking for a family link when the relationship is unknown. When a relationship is known, the probabilities primarily are used for a possible or not possible indication. A low probability percentage does not rule out the possibility of that relationship unless the probability percentage is zero (0). If the probability percentage displayed is zero then that relationship is impossible based on the amount of shared DNA (assuming no pedigree collapse or endogamy). Any non-zero probability percentage, even a very low probability, is possible. Low probabilities generally need more supporting evidence.

Random recombination of DNA can result in some test takers sharing more or less than the expected amount of DNA for a specific relationship. Relationships more distant than second cousins may result in no shared DNA at all even though the genealogical relationship is real.2

The probability numbers should be evaluated within the context of all of the evidence, DNA and documentary. The probabilities should not be used alone as confirmation of a relationship; again, any probability other than 0 indicates the relationship is possible. Probabilities for relationships for which more DNA is shared are more likely to be accurate. For more distant relationships the smaller amount of shared DNA can be typical of multiple relationships. Some probability percentages may be lower, but are consistent with the hypothetical relationship as long as the probability is not zero.

In this example shown in figure 2, there is a documented 1c2r relationship between two test takers who share 111.32 cM of atDNA. The probability that they are 1c2r is 9%, the fourth most likely percentage offered with twelve more likely relationships, four other relationships that are as likely as 1c2r, and three relationships less likely but still possible. All of these are possibilities as the probability percentage is not zero.

In cases like this, with a 9% probability, more information will be needed.


Figure 2. Relationship probability display for 111.32 shared cM from the Shared cM Tool on DNA Painter.


Using the Histograms

Histograms are displayed by clicking on a relationship box in the Shared cM Chart on the DNA Painter website. The histograms, illustrated in figure 3, are used to determine if the amount of shared DNA is at the peak of the curve, within the curve, or an outlier on the far shoulders of the histogram curve. Shared cM values that fall far out on the shoulders of the histograms or outside of the reported range are known as outliers. Outliers require additional investigation and more evidence to be accepted as true; often more test takers are needed. Outliers will often lead to more tentative or qualified hypotheses and need more explanation in the analysis.3

Figure 3 is an annotated image of the histogram displayed for the 1c2r relationship. The added red markings indicate the peak of the curve, position of values described as “within the curve,” and outliers (on the shoulders) of the curve. Numbers outside of the range of shared values are also considered outliers.

To determine where on the curve a DNA match falls, look along the horizontal axis for the numbers closest to the amount of DNA shared by two test takers. Mentally note the location for the shared cM number on the horizontal axis. Mentally draw a line up to intersect the curve. Determine if the amount of DNA shared by the two test takers is at the peak or within the curve of the histogram or if the value may be an outlier (on the shoulders of the curve or outside of the range of the curve).

Using figure 3, the number 111 falls closer to the number 100 than to 150; 111 is not far out on the shoulder of the curve, but it is not high within or near the peak of the curve.


Figure 3. Annotated image of the histogram displayed by the Shared cM Tool on DNA Painter for the 1c2r relationship.


Table 1 correlates the information gathered so far about the relationship between BJ04 and DP5—shared DNA amounts from the testing company website and also Shared cM average and range, probabilities, and placement on the histogram for the known relationship from DNA Painter.



Again, more evidence is needed. Additional family members can be tested or the DNA match list may contain serendipitous matches that add evidence to this analysis.

Gathering More Evidence

In this case, multiple siblings and a first cousin of DP5 were tested or were already listed in the DNA Match Lists. The shared DNA amounts between these test takers is shown in table 2. BJ04 is a 1c2r to all other persons listed in the table. DJP, RAP, DP4, and DP5 are full siblings. DGS is a half sibling to DJP, RAP, DP4, and DP5. PCF is a first cousin to DJP, RAP, DP4, DP5, and DGS.

The full siblings DJP, RAP, DP4, and DP5 all share between 2526.74 and 2932.92 cM (yellow highlights in table 2). The Shared cM Tool predicts a 97% to 100% likelihood of a full sibling relationship. The half sibling, DGS, shares between 1638.74 and 2077.44 cM with the other siblings (bold, red values in table 2). The Shared cM Tool predicts a 90% to 100% likelihood of a half sibling relationship. The siblings share between 865.03 and 997.11 cM with their first cousin (see the row or column for PCF in table 2). The Shared cM Tool predicts a 97% to 100% likelihood of a first cousin relationship. These probabilities indicate the known relationships are likely true.

These numbers also demonstrate the amount of shared DNA between the siblings and their first cousin is consistent with their relationships to each other. The numbers are within the Shared cM ranges and well within the histogram curves.



All of these added cousins share more DNA with BJ04 than DP5 shares (see the row or column for BJ04 in table 2). Entering these cM numbers into the Shared cM Tool on DNA Painter indicates a 1c2r relationship probability of between 34% to 62% (see table 3).

The higher probabilities that BJ04 is a 1c2r to others in the study than the 9% probability of being a 1c2r to DP5 adds more credibility to the conclusion that BJ04 is a 1c2r to all the others in this study, including DP5.

Table 3 correlates the information gathered so far about the relationship between BJ04 and all other test takers in this study—shared DNA amounts from the testing company website and also Shared cM average and range, probabilities, and placement on the histogram curve for the known relationship from DNA Painter.



The documentary research (not detailed in this blog post for privacy purposes) clearly supports the known relationships. The birth certificates, census enumerations, death certificates, obituaries, and memories of living family members are all consistent with the claimed relationships.

Together, the DNA and documentary evidence strongly support the hypothesized relationships even though, alone, the amount of DNA shared by BJ04 and DP5 was not conclusive.

This is a clear case where testing siblings and first cousins can provide DNA evidence to help answer some questions. The 111.32 cM shared by BJ04 and DP5 is low on the histogram curve. This number is not far out on the shoulders of the histogram, but it is definitely on the waning, low end of the curve.

Conclusion

Astronomer Carl Sagan made the statement, “extraordinary claims require extraordinary evidence." Wikipedia calls this statement the “Sagan standard” and tells us, "The standard illustrates a core principle of the scientific method and skepticism and can be used to assess the validity of a claim." Sagan wasn't the first to make this claim, but Cosmos may have been the first exposure for many of us.4

When the probability of a relationship is low, as it is when only 111.32 cM are shared by 1c2r, it is necessary to provide supporting evidence to increase the credibility of the conclusion. Here, the amount of shared DNA between more siblings and their first cousin with the person known to be a first cousin twice removed (1c2r) provided more evidence. If the only two test takers available were DP5 and BJ04 a genealogist could assume the 1c2r relationship might be an error. The low likelihood of the relationship of 1c2r between DP5 and BJ04 needs supporting evidence to make it more credible even though the 9% probability indicates the relationship is possible. Adding the DNA evidence from more close cousins and the documentary evidence for these relationships provides strong evidence that the relationship has been correctly identified.

For more information on the randomness of DNA inheritance see my earlier blog post, "DNA Analysis - Random is the Most Important Factor," Deb’s Delvings in Genealogy, 9 October 2017 (http://debsdelvings.blogspot.com/2017/10/dna-analysis-random-is-most-important.html).


1. Blaine T. Bettinger, Leah LaPerle Larkin, and Jonny Perl, “The Shared cM Project 4.0 tool v4,” DNA Painter (https://dnapainter.com/tools/sharedcmv4).
     Bettinger provided the Shared cM data, self-reported by (and likely to contain some errors) from actual test taker data. Blaine T. Bettinger, “The Shared cM Project, Version 4.0 (March 2020),” The Genetic Genealogist, PDF online (https://thegeneticgenealogist.com/wp-content/uploads/2020/03/Shared-cM-Project-Version-4.pdf). Page 5 covers data collection methods. Pages 8-51 cover the histograms. Also see Blaine T. Bettinger, “Shared cM Project,” The Genetic Genealogist (https://thegeneticgenealogist.com/2020/03/27/version-4-0-march-2020-update-to-the-shared-cm-project/). Also see “Collecting Sharing Information for Known Relationships,” The Genetic Genealogist (https://thegeneticgenealogist.com/2015/03/04/collecting-sharing-information-for-known-relationships/) and “Collecting Sharing Information for Known Relationships – Part II”, (https://thegeneticgenealogist.com/2015/04/06/collecting-sharing-information-for-known-relationships-part-ii/).
     Larkin provided the underlying data for the probability indications based on Ancestry.com simulated, statistical data. Also see Leah LaPerle Larkin, “The Limits of Predicting Relationships Using DNA,” 19 December 2016, The DNA Geek (https://thednageek.com/the-limits-of-predicting-relationships-using-dna/); probabilities based on simulated data citing “AncestryDNA Matching White Paper,” AncestryDNA, 31 March 2016 (https://www.ancestry.com/dna/resource/whitePaper/AncestryDNA-Matching-White-Paper).
     Perl developed the website where these tools are housed, the user interfaces, and other tools on the site. These include the Chromosome Mapper that was the initial offering at DNA Painter as well as the Cluster Auto Painter, Inferred Segment Generator, cM Estimator, several tree and pedigree tools, and more. Also see the online help at https://dnapainter.com/help.

2. Blaine T. Bettinger, “Q&A: Everyone Has Two Family Trees – A Genealogical Tree and a Genetic Tree,” The Genetic Genealogist, 10 November 2009 (https://thegeneticgenealogist.com/2009/11/10/qa-everyone-has-two-family-trees-a-genealogical-tree-and-a-genetic-tree/). Also “Cousin statistics,” International Society of Genetic Genealogists Wiki (https://isogg.org/wiki/Cousin_statistics).

3. Blaine T. Bettinger, “The Shared cM Project Version 4.0 (March 2020),” PDF online (https://thegeneticgenealogist.com/2020/03/27/version-4-0-march-2020-update-to-the-shared-cm-project/), 8–18.

4. "Sagan standard," WikiPedia, The Free Encyclopedia (https://en.wikipedia.org/wiki/Sagan_standard).



All statements made in this blog are the opinion of the post author. This blog is not sponsored by any entity other than Debbie Parker Wayne nor is it supported through free or reduced price access to items discussed unless so indicated in the blog post. Hot links to other sites are provided as a courtesy to the reader and are not an endorsement of the other entities except as clearly stated in the narrative.


To cite this blog post:
Debbie Parker Wayne, "DNA Painter's Shared cM Tool — Ranges, Probabilities, and Histograms," Deb's Delvings in Genealogy, 11 September 2021 (http://debsdelvings.blogspot.com/2021/09/dna-painters-shared-cm-tool-ranges.html : accessed [date]).

© 2021, Debbie Parker Wayne, Certified Genealogist®, All Rights Reserved

10 August 2021

Display All Posts on this Blog




    All statements made in this blog are the opinion of the post author. This blog is not sponsored by any entity other than Debbie Parker Wayne nor is it supported through free or reduced price access to items discussed unless so indicated in the blog post. Hot links to other sites are provided as a courtesy to the reader and are not an endorsement of the other entities except as clearly stated in the narrative.


    To cite this blog post:
    Debbie Parker Wayne, "Display All Posts on this Blog," Deb's Delvings in Genealogy, 10 August 2021 (http://debsdelvings.blogspot.com/ : accessed [date]).

    © 2021, Debbie Parker Wayne, Certified Genealogist®, All Rights Reserved

    28 July 2020

    TxSGS 2020 Summer Virtual Conference

    The virtual attendance riches just keep getting better this summer.

    August 7-8, two great days with some of the best genealogy speakers:
    • Colleen Robledo Greene: Taking a Closer Look at Immigration Records for Your Mexican Ancestor
    • Patti Lee Hobbs: Problem Solving with DNA: Case Studies
    • J. Mark Lowe: Mapping, Atlases & Documenting Paths
    • Sunny Morton: Collateral Kin: Indirect Routes to Direct Ancestors
    • Diane L. Richard: 50 Overlooked Online Genealogy Resources in 50 Minutes
    • Drew Smith: Organizing Your Genealogy
    • Michael Strauss: Researching Your World War II Ancestors
    • Ari Wilkins: Studying a Community Using Sanborn Maps and Other Resources
    Register today and get more information at https://www.txsgs.org/2020/07/16/register-today-for-txsgs-2020-summer-virtual-conference/.


    All statements made in this blog are the opinion of the post author. This blog is not sponsored by any entity other than Debbie Parker Wayne nor is it supported through free or reduced price access to items discussed unless so indicated in the blog post. Hot links to other sites are provided as a courtesy to the reader and are not an endorsement of the other entities except as clearly stated in the narrative.


    To cite this blog post:
    Debbie Parker Wayne, "TxSGS 2020 Summer Virtual Conference," Deb's Delvings, 28 July 2020 (http://debsdelvings.blogspot.com/ : accessed [date]).

    © 2020, Debbie Parker Wayne, Certified Genealogist®, All Rights Reserved

    13 June 2019

    Kindle version available - Advanced Genetic Genealogy: Techniques and Case Studies

    The Kindle version of Advanced Genetic Genealogy: Techniques and Case Studies is now available. Order links and a complete list of chapters and authors are available on the book landing page at http://debbiewayne.com/aggtcs/index.php.


    Please consider leaving a review on Amazon letting others know what you think of the book.

    Corrections listed in the errata on the book landing page at http://debbiewayne.com/aggtcs/index.php are incorporated in the Kindle and a second print version of the book. The landing page is periodically updated with the latest information on reviews and status of versions to allow anyone who purchases an early version of the book to track changes. Some print books are in the sales pipeline so there will be a time lag before the updated print version will be shipped to readers.

    Thanks to all of the readers who have posted on Facebook, blogs, Amazon, and those who have emailed letting us know what you think of the book. All feedback is appreciated.




    All statements made in this blog are the opinion of the post author. This blog is not sponsored by any entity other than Debbie Parker Wayne nor is it supported through free or reduced price access to items discussed unless so indicated in the blog post. Hot links to other sites are provided as a courtesy to the reader and are not an endorsement of the other entities except as clearly stated in the narrative.


    To cite this blog post:
    Debbie Parker Wayne, "Kindle version available - Advanced Genetic Genealogy: Techniques and Case Studies," Deb's Delvings, 13 June 2019 (http://debsdelvings.blogspot.com/ : accessed [date]).

    © 2019, Debbie Parker Wayne, Certified Genealogist®, All Rights Reserved

    12 June 2019

    All-day DNA Seminar, June 29th, Denver Public Library

    I will be presenting an all-day DNA seminar at the Denver Public Library on 29 June 2019. My only other visits to Denver were driving through when I was 12 years old and a visit to the Ramses II exhibit in about 1988 to 1989. I am looking forward to seeing more of the area this time.

    Free and open to the public. No registration required. Doors open at 9am.

    Topics include how DNA keeps providing new information, essential tools, organizing data, and writing your results to inspire family to participate.




    All statements made in this blog are the opinion of the post author. This blog is not sponsored by any entity other than Debbie Parker Wayne nor is it supported through free or reduced price access to items discussed unless so indicated in the blog post. Hot links to other sites are provided as a courtesy to the reader and are not an endorsement of the other entities except as clearly stated in the narrative.


    To cite this blog post:
    Debbie Parker Wayne, "All-day DNA Seminar, June 29th, Denver Public Library," Deb's Delvings, 12 June 2019 (http://debsdelvings.blogspot.com/ : accessed [date]).

    © 2019, Debbie Parker Wayne, Certified Genealogist®, All Rights Reserved

    20 May 2019

    Book Signing: Advanced Genetic Genealogy: Techniques and Case Studies

    Many of the authors of Advanced Genetic Genealogy: Techniques and Case Studies autographed books at the US National Genealogical Society (NGS) and Ohio Genealogical Society (OGS) conferences held in May 2019. We really appreciate all of the kind words and enjoyed meeting so many readers! Thank you to everyone who bought books at the conference, who brought previously purchased books for us to sign, and also to those who did not want to cart around a big heavy book yet told us how much you enjoy the book or hope to when you receive it after ordering online.

    Here are some of the photos I have from the three conferences I have attended since the book was released. We did not have books to sign at the FamilyTreeDNA conference, but we had one print proof to show to the attendees. Space considerations did not allow all of the authors at NGS to sign at one time so we staggered time slots to give everyone a chance to get signatures of all authors in attendance.

    I hope some of you will send me photos of book signings at upcoming events I will not be able to attend. There will be book signing events at IGHR. Many of the authors will be in attendance at SoCal Jamboree and GRIP although I know of no planned signing events at those places yet. I'm hoping Debbie Kennett gets to sign books at the upcoming events in the UK and sends photos.

    Jim Bartlett, Debbie Parker Wayne, and Patricia Lee Hobbs were all at the FamilyTreeDNA Project Administrator's conference in Houston in March:

    Michael Lacopo signed books at the OGS conference:

    Blaine T. Bettinger and Judy G. Russell signed books at the NGS conference:

    Patrica Lee Hobbs and Kimberly Powell signed books at the NGS conference:

    Thomas W. Jones and Karen Stanbary signed books at the NGS conference:

    Karen Stanbary, Blaine T. Bettinger, and Debbie Parker Wayne signed books at the NGS conference:

    Those last two images also include my beaded representation of the first 36 base pairs of my actual mtDNA sequence. I created this a year or two ago to have an interesting display of DNA for events. As I have told several people, if I were going to do this again I would definitely hire an experienced beader and not try to do this myself! But I would love to see more crafty representations of DNA. Here, I used a bead whose color name starts with the same letter as the DNA chemicals represented: Amber = A = adenine, Cyan = C = Cytosine, Green = G = Guanine, and Tangerine = T = Thymine. Brown beads and the wire represent the sugars and phosphates.


    Images from NGS and OGS conferences provided by Pat Gordon of Books and Things (http://www.mygenealogybooks.com/) with permission to use. Many thanks to Pat and Bob Gordon of Books and Things for sponsoring our book signing events! Ordering from Books and Things supports our genealogical book sellers. Those outside of the US should consider buying through Amazon or your local book store as the cost of international shipping is prohibitive. Because this book is available through the Ingram book distributor catalog, any bookseller or library worldwide should be able to order the book using the ISBN 978-1-7336949-0-2.

    I am disappointed I cannot make it to IGHR, SoCal Jamboree, GRIP, and FGS to be able to sign more books, but some authors will be at all of those events. I will be at an all-day seminar in Denver, Colorado, on June 29th; the BCG Board meeting in SLC the first week in September; an all-day seminar in Plano, Texas, on September 28th; and the Texas State conference in Houston on October 11-13th. More will be available later as to which events will have book sellers there. Anyone who has a book can bring it to be signed. I hope to see many of you at upcoming events and I am sure the other authors are also looking forward to meeting more of our readers.


    2019-05-21: Changed one of the photos.

    All statements made in this blog are the opinion of the post author. This blog is not sponsored by any entity other than Debbie Parker Wayne nor is it supported through free or reduced price access to items discussed unless so indicated in the blog post. Hot links to other sites are provided as a courtesy to the reader and are not an endorsement of the other entities except as clearly stated in the narrative.


    To cite this blog post:
    Debbie Parker Wayne, "Book Signing: Advanced Genetic Genealogy: Techniques and Case Studies," Deb's Delvings, 20 May 2019 (http://debsdelvings.blogspot.com/ : accessed [date]).

    © 2019, Debbie Parker Wayne, Certified Genealogist®, All Rights Reserved

    Genetic Genealogy Abbreviations and Terms Quick Reference

    Now available, Practical Genetic Genealogy Abbreviations and Terms Quick Reference laminated guide.

    I was asked to compile a laminated quick reference guide for DNA and genetic genealogy abbreviations and terminology. Even though the ISOGG Wiki and other online sources contain much of this information, it seems many people prefer to have the information available in a laminated guide.


    This quick reference guide has several advantages over online access.
    1. The definitions needed by genealogical researchers are in one easy-to-access place.
    2. Both beginner and intermediate level terms are included.
    3. These are clearly-worded definitions that are easy for non-biologists to understand. I often receive praise for being able to explain DNA in a way that is easy to understand and I tried to continue that tradition here.
    4. An image of my gingerbread men used to explain DNA inheritance patterns is included. I am constantly asked to provide color versions of this image to students. The image has two couples on the top row, a male and female child of the couples on the middle row, and four grandchildren on the bottom row. A "Y" represents the inheritance path of the Y chromosome through the family. An "O" represents the inheritance path of the mitochondrial DNA through the family. The left half of the gingerbread bodies represent one autosomal chromosome (for example, chromosome one) inherited from the father. The right half of the gingerbread bodies represent the corresponding autosomal chromosome inherited from the mother. The colors of the autosomal DNA represent randomly recombined chromosomes and the colors can be traced back to the great-grandparents not shown on the chart. The colors make it easy to see fully identical regions (FIR) and half identical regions (HIR) of DNA shared by the siblings in the bottom row.

    The quick reference sheet is currently available from Books and Things (http://www.mygenealogybooks.com/) priced with shipping included.




    All statements made in this blog are the opinion of the post author. This blog is not sponsored by any entity other than Debbie Parker Wayne nor is it supported through free or reduced price access to items discussed unless so indicated in the blog post. Hot links to other sites are provided as a courtesy to the reader and are not an endorsement of the other entities except as clearly stated in the narrative.


    To cite this blog post:
    Debbie Parker Wayne, "Genetic Genealogy Abbreviations and Terms Quick Reference," Deb's Delvings, 20 May 2019 (http://debsdelvings.blogspot.com/ : accessed [date]).

    © 2019, Debbie Parker Wayne, Certified Genealogist®, All Rights Reserved

    23 March 2019

    Now available: Advanced Genetic Genealogy: Techniques and Case Studies

    For Immediate Release

    NEW ON DNA: Advanced Genetic Genealogy: Techniques and Case Studies

    More researchers than ever are using DNA for genealogy and adoption research. There are many books on this subject, but only Advanced Genetic Genealogy: Techniques and Case Studies works through actual cases showing how to use advanced analysis techniques and genealogy standards to get results.

    Advanced Genetic Genealogy: Techniques and Case Studies will help intermediate researchers move up to the next level and advanced researchers apply the new DNA standards and write about DNA. This new book offers an in-home course in advanced genetic genealogy. It includes about 400 pages, 136 images, most in full-color, and dozens of tables demonstrating analysis techniques, tracking of DNA information, and writing about DNA. Each of the fourteen chapters was written by a professional genealogist with DNA experience.

    Eight chapters study real families (some using anonymized identities), including methods, tools, and techniques.
    • Jim Bartlett covers how to triangulate a genome (mapping DNA segments to ancestors).
    • Blaine T. Bettinger demonstrates visual phasing (mapping DNA segments to the grandparents who passed down a particular segment to descendants, even when the grandparents cannot be tested).
    • Kathryn J. Johnston shows how to use X-DNA to identify and confirm ancestral lines.
    • James M. Owston describes findings of the Owston Y-DNA project.
    • Melissa A. Johnson covers adoption and misattributed parentage research.
    • Kimberly T. Powell provides guidance (and hope!) for those researching families with endogamy and pedigree collapse.
    • Debbie Parker Wayne combines atDNA and Y-DNA in a Parker family study.
    • Ann Turner describes the raw DNA data and lab processes.

    Three middle chapters cover genealogy standards as they relate to DNA and documentary evidence.
    • Karen Stanbary applies the Genealogical Proof Standard (GPS) to genetic genealogy in a hypothetical unknown parentage case illustrating start-to-finish analysis.
    • Patricia Lee Hobbs uses atDNA to identify a real-life unknown ancestor and that ancestor's maiden name, moving back and forth between documentary and DNA evidence.
    • Thomas W. Jones describes best practices for genealogical writing and publishing incorporating DNA evidence.

    Three concluding chapters deal with ethics, emotions, and the future.
    • Judy G. Russell covers ethical issues and considerations.
    • Michael D. Lacopo describes the effect on relationships when family secrets are uncovered, surfacing issues for all concerned.
    • Debbie Kennett covers the current limitations and future promise of using DNA for genealogy.
    An extensive glossary, list of recommended resources, and index are included.

    Advanced Genetic Genealogy: Techniques and Case Studies will be available at Books and Things in the NGS conference exhibit hall, Booth 401 (near the front aisle). Reviews and order links for Amazon (print versions) are available at https://www.amazon.com/Advanced-Genetic-Genealogy-Techniques-Studies/dp/1733694900/ and other venues are available at http://debbiewayne.com/aggtcs/ (or at http://debbiewayne.com/ then click on Publications).

    A Kindle version is scheduled for May availability if all goes well. An announcement will be made when it is available.



    All statements made in this blog are the opinion of the post author. This blog is not sponsored by any entity other than Debbie Parker Wayne nor is it supported through free or reduced price access to items discussed unless so indicated in the blog post. Hot links to other sites are provided as a courtesy to the reader and are not an endorsement of the other entities except as clearly stated in the narrative.


    To cite this blog post:
    Debbie Parker Wayne, "Now available: Advanced Genetic Genealogy: Techniques and Case Studies," Deb's Delvings, 23 March 2019 (http://debsdelvings.blogspot.com/ : accessed [date]).

    © 2019, Debbie Parker Wayne, Certified Genealogist®, All Rights Reserved

    10 March 2019

    DNA Standards - Part 8

    For "DNA Standards - Part 1" see https://debsdelvings.blogspot.com/2019/03/dna-standards-part-1.html. In the first part I paraphrased the standards for using DNA evidence for genealogy into bullet points.

    This is the post for "DNA Standards - Part 8."


    1

    Prior bullets are discussed in other parts of this series:


    In "DNA Standards - Part 8" I further discuss the final bullet. The main bullets indicate considerations when using DNA to help answer a research question; sub-items explain what is needed to accomplish the tasks defined in the main bullet:

    • publish or share only as a living test taker’s permission allows (Standard 57)
      • deceased persons have no privacy rights; courtesy to living descendants might warrant anonymizing the identity of a deceased test taker
      • general information can be shared as long as the identifying information is hidden (such as when asking for assistance or when teaching how to use a site or tool)

      • do not use a living person’s DNA results if they do not give permission (some disagree on whether inclusion in a public DNA project constitutes permission)
      • do not identify a living person if they do not give permission
        • identities can be anonymized
        • anonymizing too many people in a study may make the conclusion questionable

    Unless you are working in a legal capacity where you may be held liable for misidentifying descendants you should be able to use whatever sources you wish to use. If you are publishing, your work will be subject to the requirements of the editor. If you are submitting a portfolio to BCG, your work will be subject to the requirements of BCG. You should contact those entities with your questions.

    There will always be disagreements about what constitutes proof. I have read articles in some of the premier genealogical journals that I do not think meet the threshold for the claims made. Obviously, the editors and peer-reviewers felt differently. Some of those articles were based only on documents and some included DNA. We will never all agree on exactly how much evidence is needed for proof and DNA does not change that fact.





    BCG, Genealogy Standards, 2nd ed. (Nashville: Ancestry, 2019)

    GETTING OFFICIAL INFORMATION ON STANDARDS FROM BCG

    Only BCG provides official answers on what it expects to see in application portfolios. No one, not even members of the BCG Board of Trustees or associates helping at exhibit hall booths, speak officially for BCG. For specifics on what BCG expects to see in portfolios, please use BCG’s website, blog, newsletter, and other means of communication:



    All statements made in this blog are the opinion of the post author. This blog is not sponsored by any entity other than Debbie Parker Wayne nor is it supported through free or reduced price access to items discussed unless so indicated in the blog post. Hot links to other sites are provided as a courtesy to the reader and are not an endorsement of the other entities except as clearly stated in the narrative.


    To cite this blog post:
    Debbie Parker Wayne, "DNA Standards - Part 8," Deb's Delvings, 10 March 2019 (http://debsdelvings.blogspot.com/ : accessed [date]).

    © 2019, Debbie Parker Wayne, Certified Genealogist®, All Rights Reserved

    DNA Standards - Part 7

    For "DNA Standards - Part 1" see https://debsdelvings.blogspot.com/2019/03/dna-standards-part-1.html. In the first part I paraphrased the standards for using DNA evidence for genealogy into bullet points.

    This is the post for "DNA Standards - Part 7."


    1

    Prior bullets are discussed in other parts of this series:


    In "DNA Standards - Part 7" I further discuss the eighth bullet. The main bullets indicate considerations when using DNA to help answer a research question; sub-items explain what is needed to accomplish the tasks defined in the main bullet:

    • make the DNA data available for verification, as much as possible within the limits of test taker permissions (Standard 54)
      • depending on publication venue this might mean
        • providing login information to an editor to confirm the DNA data (the password can be changed after the editor has completed the review)
        • asking test takers to upload to a public project (such as at FamilyTreeDNA where the test taker gives permission and the administrator sets project options for results to be displayed publicly)
        • asking test takers to upload to a publicly available third-party website (available to any internet user without logging in or requiring a login and password that any person can obtain)
        • providing screenshots of web pages with the DNA or match data
      • if the DNA test results are not publicly shared or confirmed by an unbiased third party there is a risk that the author misinterpreted the DNA test results
      • if one or more test takers choose to remain unidentified the credibility of the conclusion should be evaluated with that person removed or anonymized
      • if one or more test takers choose to remain unidentified the essay may not meet the criteria for some publications nor be the best choice of work sample to demonstrate your analysis and correlation skill
      • just as we have always done with articles and work samples based on documentary sources, we must make judgments on credibility when using DNA sources


    Additional bullets will be discussed in other parts of this series:



    BCG, Genealogy Standards, 2nd ed. (Nashville: Ancestry, 2019)

    GETTING OFFICIAL INFORMATION ON STANDARDS FROM BCG

    Only BCG provides official answers on what it expects to see in application portfolios. No one, not even members of the BCG Board of Trustees or associates helping at exhibit hall booths, speak officially for BCG. For specifics on what BCG expects to see in portfolios, please use BCG’s website, blog, newsletter, and other means of communication:



    All statements made in this blog are the opinion of the post author. This blog is not sponsored by any entity other than Debbie Parker Wayne nor is it supported through free or reduced price access to items discussed unless so indicated in the blog post. Hot links to other sites are provided as a courtesy to the reader and are not an endorsement of the other entities except as clearly stated in the narrative.


    To cite this blog post:
    Debbie Parker Wayne, "DNA Standards - Part 7," Deb's Delvings, 10 March 2019 (http://debsdelvings.blogspot.com/ : accessed [date]).

    © 2019, Debbie Parker Wayne, Certified Genealogist®, All Rights Reserved