What is a Genetic Genealogist?

Is there such a thing as a “genetic genealogist” in genealogy today? Should there be such a thing?

In a previous post (“The DNA Era of Genealogy“) we talked about how DNA is a record type, similar to a census record, land record, vital record, or tax record. All of these record types provide evidence that – when combined with other types of evidence – support, weigh against, or reject a genealogical hypothesis.

However, DNA alone cannot prove anything; DNA evidence must be combined with other types of evidence in order to arrive at a solid genealogical conclusion. As a result, it is impossible to be a genetic genealogist and nothing else. To use DNA evidence properly (or at least to its fullest potential), one must also be a good genealogist.

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Assistance Needed!

As you know, I’ve been collecting submissions of known relationships and shared cMs for the Shared cM Project for about 1.5 years, and I have more than 10,000 submissions. (If you have submitted yet and would like to, the form is HERE).

I have a ton of data and recently provided an update (see “Update to the Shared cM Project“). However, there is still much to do. For example, I’d like to analyze the following:

  • Longest segment analysis
  • Known endogamy/pedigree collapse versus no known endogamy pedigree collapse
  • Company breakdowns (23andme v. AncestryDNA v. Family Tree DNA v. GEDmatch)
  • Others? (I’m open to suggestions!)

But I need help! I have time to oversee and assist with the analysis, but I just don’t have time to do it all myself. If you have statistics experience or are otherwise able to assist me with this project over the next month or two, please contact me at blainebettinger@gmail.com. Include your experience and your interest in the project. Thank you!

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The DNA Era of Genealogy

When does DNA prove a relationship? When is a triangulation group sufficiently large enough to prove descent from an ancestral couple? When is a shared DNA segment large enough to prove someone is your first (or second/third/fourth, etc.) cousin? At what point does the DNA prove that I am descended from Samuel Snell? When does the DNA prove that you’ve found your great-grandmother’s biological parents?

NEVER.

And this is, perhaps, one of the greatest misconceptions in the post-DNA era of genealogy.

What is Proof?

Genealogy is the study of lives and relationships. Accordingly, genealogists spend much of their time identifying, hypothesizing, supporting, and sometimes rejecting, relationships.

Unless you have direct knowledge of a relationship (and even sometimes when you do), you identify relationships using evidence that you’ve gathered from multiple different sources (including DNA, census, land, tax, vital, and many other types of records).

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Visual Phasing: An Example (Part 5 of 5)

Five-Part Series on Visual Phasing:

In “Visual Phasing: An Example (Part 1),” we identified and labeled all of the recombination points in the three siblings, Susan, Brooke, and Felix. Then, in Part 2 of the series, we used the identified and labeled recombination points to assign segments of DNA to the four grandparents (the blue grandparent and grey grandparent pair, and the purple grandparent and green grandparent pair). In Part 3 of the series, we used cousin matching to identify the grandparental source of the chromosomal segments. And finally, in Part 4 of the series, we characterized my paternal chromosome.

After Part 3, we had the following for Brooke, Susan, and Felix:

step4g

Now that we have this information, let’s see if we can use that to explore new matches with Brooke, Susan, and Felix.

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Visual Phasing: An Example (Part 4 of 5)

Five-Part Series on Visual Phasing:

In “Visual Phasing: An Example (Part 1),” we identified and labeled all of the recombination points in the three siblings, Susan, Brooke, and Felix. Then, in Part 2 of the series, we used the identified and labeled recombination points to assign segments of DNA to the four grandparents (the blue grandparent and grey grandparent pair, and the purple grandparent and green grandparent pair). In Part 3 of the series, we used cousin matching to identify the grandparental source of the chromosomal segments. After Part 3, we had the following for Brooke, Susan, and Felix:

step4g

Since Felix is my father and Susan and Brooke are my aunts, I might be able to compare my DNA to my aunts in order to identify which of the segments I obtained from my father.

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Visual Phasing: An Example (Part 3 of 5)

Five-Part Series on Visual Phasing:

In “Visual Phasing: An Example (Part 1),” we identified and labeled all of the recombination points in the three siblings, Susan, Brooke, and Felix. Then, in Part 2 of the series, we used the identified and labeled recombination points to assign segments of DNA to the four grandparents (the blue grandparent and grey grandparent pair, and the purple grandparent and green grandparent pair):

step4b

But without more information, we don’t know to which grandparent each segment belongs.

Today, we’ll use cousin matching (defining “cousin” to mean anyone other than the siblings) to first identify the maternal pair of chromosomes, and the paternal pair of chromosomes. Hopefully, in the process, we’ll be able to assign the segments to each of the four grandparents, rather than just maternal/paternal.

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Visual Phasing: An Example (Part 2 of 5)

Five-Part Series on Visual Phasing:

In “Visual Phasing: An Example (Part I),” we identified and labeled all of the recombination points in the three siblings, Susan, Brooke, and Felix:

step-3a

In Part 2 of the series, we’ll use the identified and labeled the recombination points to assign segments of DNA to the four grandparents.

Step 3 – Fill in Chromosomes

The next step is to fill in the chromosomes using the identified recombination points. We’re going to start with the fully identical region shared by Susan and Brooke, shown in the red square in the next image. We can fill into both chromosomes for Susan and Brooke (the blue and purple segments):

step-3b

Each of the blue and purple segments is one of the following segments: (i) paternal grandfather; (ii) paternal grandmother; (iii) maternal grandfather; or (iv) maternal grandmother. We’ll try to figure out which is which later.

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Visual Phasing: An Example (Part 1 of 5)

Five-Part Series on Visual Phasing:

  • Part I – Explaining visual phasing and identifying/labeling recombination points (November 21, 2016)
  • Part II – Assigning segments of DNA (November 22, 2016)
  • Part III – Using cousin matches to identify which grandparent provided the segments
  • Part IV – Mapping my own chromosome using the visually phased paternal chromosomes
  • Part V – Using the mapped DNA with new matches

This weekend, I spoke at a meeting of the New England chapter of the Association of Professional Genealogists, and it was a wonderful group. One of my talks was about “Chromosome Mapping.” Unfortunately, since the talk was only an hour, we didn’t have time to discuss “Visual Phasing,” a chromosome mapping methodology. Instead, I promised to finish this blog post to explain the process. As I was writing, the blog post turned into a 5-part series!

Quick Summary

  • What is it? A method to assign segments of DNA to the test-taker’s four grandparents.
  • Why use it? To identify which grandparent gave the test-taker which segments of DNA (eliminating 75% of the family tree to search for MRCA).
  • What do you need? Autosomal DNA of three siblings uploaded to GEDmatch.

Visual Phasing

Visual Phasing is a process by which the DNA of three siblings is assigned to each of their four grandparents using identified recombination points, without requiring the testing of either the parents or grandparents. Although the process does not automatically reveal which segment belongs to which of the four grandparents, matching with cousins provides this identification as a further step of the process.

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Announcing “The Family Tree Guide to DNA Testing and Genetic Genealogy”

s7981_new01I am so happy to officially announce “The Family Tree Guide to DNA Testing and Genetic Genealogy,” my effort to help people understand DNA and genetic genealogy. The book, published by Family Tree Books, is 240 pages long and covers every aspect of DNA testing for ancestry research:

  • Part One: Getting Started – Genetic Genealogy Basics; Common Misconceptions; and Ethics and Genetic Genealogy
  • Part Two: Selecting a Test – Mitochondrial-DNA (mtDNA) Testing; Y-Chromosomal (Y-DNA) Testing; Autosomal-DNA (atDNA) Testing; and X-Chromosomal (X-DNA) Testing
  • Part Three: Analyzing and Applying Test Results – Third-Party Autosomal-DNA Tools; Ethnicity Estimates; Analyzing Complex Questions with DNA; Genetic Testing for Adoptees; and The Future of Genetic Genealogy
  • Appendices – Comparison Guides; Research Forms; and More Resources

For a preview of the book, you can visit the Amazon page or Google Books.

As you’ll see, the book is full of color images that help explain all aspects of DNA and genetic genealogy, like the following (only a portion of each are shown):

siblings

flowchart2

Here are a few reviews of The Guide:

You can also hear me talk about The Guide on Episode #8 of The Genealogy Connection with Drew Smith.

The book is available for purchase at the following:

And, if you’ve purchased and read The Guide, please consider leaving a review at Amazon!

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Second Cousins (Or Closer) That Don’t Share DNA?

Caution should always be taken before pursuing an answer to a genealogical question. Ask yourself (or your relative) before diving into the research whether you really want to know the answer, and whether you think you are prepared for it. Just because you as a genealogist may be prepared for the result does not mean everyone in your family will be.

This is as true with DNA evidence as it is with any other type of genealogical evidence. Just as a census record or birth certificate can reveal a family secret, so can the results of a DNA test. The Genetic Genealogy Standards, for example, make clear that unexpected results can occur:

12. Unexpected Results. Genealogists understand that DNA test results, like traditional genealogical records, can reveal unexpected information about the tester and his or her immediate family, ancestors, and/or descendants. For example, both DNA test results and traditional genealogical records can reveal misattributed parentage, adoption, health information, previously unknown family members, and errors in well-researched family trees, among other unexpected outcomes.

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