Genetic Genealogy: Chapter 4

 Chapter 4: Genealogical Applications for mtDNA

Exercises. All the questions refer to diagrams in Appendix A: page 136

1. Which descendants shown inherited the mtDNA of Mary Ann (Smith) Jones (2): 3, 4, 5, 11, 12, 21, 22, 33. 

Mary Smith passed her mtDNA to all her children; 3, 4, 5. Her son 3 Albert, did not pass his mtDNA to his children. His children got their mtDNA from their mother, 6.

One daughter, Mary 4, had only a son, 11. That son had mtDNA from 2, but did not pass it to his children. They instead got mtDNA from his wife, their mother, 15. 

Her daughter Emma, 5, passed her mtDNA to her daughter Emma, 12. Emma 12's daughter Mandy 21 gave the mtDNA from 2 to her daughter, Mandella, 33. Emma Crocker 12 also passed mtDNA from 2 to her son Max 22. Max had a daughter who had the mtDNA from her mother, 28. 

2. Ira Gerball 20 died in Vietnam. ... Which people on the chart share the same mtDNA as Ira for purposes of identifying his remains? 

Three people in the chart share his mtDNA; his mother, Marie 15, her daughter Florence 19, and Florence' daughter Janice 31 and her son Ryan 43. Any of these people can be tested and any of them should match.

3. Adoptee Angela has narrowed her possible birth parent to cousins Mandella 33 or Emmy Wick 34, both of whom are dead and have no descendants. 

a) If the parents of Emmy Wick agree to be tested, could this help her find the answer? 

If:

No match to both: Her father Max 22 will have the mtDNA of his mother 22 who gave him Mary Smith 2's mtDNA. Her mother 28 Emmy Martin has her mother's mtDNA not shown to be a relative of Max on this chart. So a non match to both rules out their daughter Emmy 28. 

A match to Max 22 means that Mandella 33 could be the mother, since Mandella and Max share the same mtDNA.

A match to Emmy 28 means that Emmy 34 could be the mother, since they share the same mtDNA. 

b) What is the conclusion if Angela's test matches both Max 22 and Emmy 28? 

While no relationship between Max' family and Emmy Martin's, that does not mean that they share a maternal line so far undiscovered. It would not answer Angela's question of which cousin could be her birth mother. 

4. Two woman have taken full-mtDNA tests but show no match. However, they may share a female ancestor Tempy Gordy. Do the test results rule out a relationship in the female line? 

No. Because the differences are not "fast changing" differences from the CR, they may or may not be significant. The common ancestor link is speculative on one of the trees. Therefore, more genealogical work may need to be done to resolve this question, and more testing of descendants of Tempy Gordy may help as well. 

5. Annabell Martin wants to prove that her 5th great-grandmother was Cherokee, as family stories have said. Which of the following must be true for an mtDNA test to prove the story?

a) Direct matrilineal line between Annabell and her ancestor

b) Direct matrilineal line between willing test-taker and the ancestor

c) A full mtDNA test

d) A low or medium-resolution test

e) at least 3 test-takers

B and D must both be true, however the results at best can indicate native American; not a specific tribe. Documentary and historical evidence would be needed to find a specific tribe or tribes.

A - Any matrilineal descendant can take the test

C - While a full test might be useful for other purposes, it is not necessary to find the haplogroup

E - The haplogroups native peoples are known; more tests are not necessary for this purpose.

6. Two test-takers who suspect a common ancestor on the matrilineal line take medium-resolution mtDNA tests (HVR1 & HVR2). Neither appears in the match list of the other. Their lines back to the ancestor are well-documented.

 

a) Does the fact that the test-takers do not match preclude Jane (Vick) Otis from being the mother of of both Mary Otis and Elizabeth Otis? 

No. If the haplogroups were not a match, then yes. Mutations are random, so the lack of a match is not conclusive.

b) Would a full mtDNA test help answer the question? 

Perhaps. A full mtDNA test might be more conclusive, but that is not certain.

c) What other things might be considered, based on the lineages shown? 

An au test (or tests) might provide more evidence. Many au tests might have to be run since this is at the edge of the genetic tree for some descendants. Since the mother-daughter relationships are suggested by the common place, Rowan County, North Carolina and suitable ages, and a shared haplogroup, more focused research could be done in that county.

7. Sarah and Jane upgrade to Full mtDNA tests and receive results; still do not appear in one another's match list.

a) Does the fact that the test-takers do not match preclude Jane (Vick) Otis from being the mother of of both Mary Otis and Elizabeth Otis? Do they proved that Jane is mother of both Mary and Elizabeth?

No, and no. The results do not answer the questions.

b) Do these results explain why neither appears in the match list of the other?

Yes, their differences fall outside of the parameters set by the testing company for showing a match.

c) What do the Ys and Rs in the list of mtDNA differences from the reference sequence mean?

These are both heteroplasmies Y = C or T, R = A or G. If both of their shared heteroplasmies could share common values, then they could have a close enough match to perhaps answer their genealogical question, so more close analysis could be done.

* Note: I did consult the "answers in the back of the book" in order to check that my blog post accurately reflects the information from the book. Also note: mitosearch.org no longer exists. Please consider uploading mtDNA test results to both https://www.mitoydna.org/ and YFull: https://www.yfull.com/ ($)