Wednesday, 11 January 2017

DNA analysis: slow progress

My husband Greg and I had our DNA analysed by ancestry.com in May 2016. The results became available in July. Over the last six months I have spent many hours trying to make sense of the results and contacting DNA cousins.

As a way of learning more about our family history DNA analysis has not been very useful.

At the time of testing I put forward three brick walls the DNA testing might help me get past:

  • Henry Sullivan (1862-1943), a great grandfather of my husband, was admitted as a state ward in Geelong in 1866 about the age of four. His parents had deserted him. 
  • George Young (1826-1890), from Liverpool, a great great grandfather of my husband, provided no information about his parents. 
  • Caroline Clarke (1835-1879), wife of George Young and a great great grandmother of my husband, was not specific about her birth and I have been unable to trace her parents, perhaps John Clark(e) and Hannah Sline. She said she was born about 1835 in Tumut. But she also said she was born in Sydney. 

I have made no progress on the history of George Young or  his wife Caroline Clarke.

DNA testing has provided some evidence that the hypothesis I explored for Henry Sullivan's family in my blog post of May 2016 is correct. It adds to the body of evidence which includes newspaper reports, an inquest, state ward records and birth, marriage and death records, all of which point to a connection.

MBH, a descendant of Henry's probable half-brother, has tested. She matches Greg, his first cousin Barry, and a second cousin of Greg's, LB, also descended from Henry Sullivan. My research suggests that MBH is Greg's third cousin,. They share a common great great grandmother but are descended from children of that great great grandmother by different fathers. AncestryDNA predicted the relationship between MBH and Greg as 4th cousins with 21.4 centimorgans shared across two segments.

chart showing family connections of related DNA tests


Three of the test results have been uploaded to GedMatch so that we can look at how the DNA inheritance aligns. However, the DNA from the three samples does not match on the same segments. 

GedMatch shows the match between Greg and MBH as having only one segment on chromosome 1 of 23.4 centimorgans. It predicts their relationship as having the most recent common ancestor within 4.6 generations. By lowering GedMatch's default thresholds I find that the second segment is a match on chromosome 2 of 5.9 centimorgans, a size regarded as not genealogically significant. Lowering the threshold still did not reveal a matching segment shared by Greg with both MBH and LB.

Barry, a first cousin of Greg's, also on the Sullivan side, has tested. He has yet to upload to GedMatch. The tools provided by ancestryDNA show that he shares DNA with Greg, MBH and a third person, IB. Barry separately shares DNA with Greg and LB, that is, Barry and Greg inherited different segments that they share with MBH compared to the segments shared by LB and MBH.

Greg, Barry, and MBH share DNA with a fourth man, IB. IB has a private tree on ancestry.com. Unfortunately he has not responded to my several attempts to contact him. As far as I know he is not a descendant of Henry Sullivan. MBH is unaware of his being a cousin. IB is predicted to be a fourth cousin of Greg's. His tree (865 people) does not appear to contain the surnames Hughes or Sullivan. 

Although it is likely that the DNA matching is for the hypothesised Sullivan and Hughes connections, it is not certain. We don't have enough shared matches on a specific segment to be confident that the shared DNA demonstrates shared heredity.  Greg, LB and MBH have family trees that have been researched over considerable time and go back a number of generations. There don't seem to be any other likely connections between the family trees.

Ancestry.com's DNA database continues to expand rapidly with over 3 million participants to date. Future matches may well provide more definite confirmation of inherited DNA from Matilda Sullivan née Hughes, the mother of Eleazer and probable mother of Henry.

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