Another DNA Dering DNA Match with David Christian – Maybe or Not ?

David Christian undertook DNA testing with in early 2017, with his data transferred to other sites. Over two years later, in August 2019, a DNA match with another identified Dering descendant appeared in David’s lists of suggested DNA matches. Based on genealogical research, the Most Recent Common Ancestor (MRCA) for David and that 2019 DNA match was Sir Edward Dering – 6th Baronet of Surrendon Dering (1732 – 1798).

Nearly a year later, in July 2020, an even more distant DNA match with a Dering descendant was identified  on Gedmatch – using the then new Tier 1 Tool. This tool compares both DNA results and Gedcom Family Trees – see DNA Explained post and Kitty Cooper Blog post. This 2020  match was found to be in David’s matches in FamilyTreeDNA, along Chromosome 1.

This new 2020 match of 9.3 cms, is a descendant of David’s 13 x great grandparents Sir Richard Dering and Margaret Twisdens daughter  Lady Benetta Dering, whereas David descends from Lady Benetta’s brother Sir Anthony Dering – see the family trees below.

By July 2020, it had been identified that David and this match share four direct Plantagenet ancestral lines going back to Margaret Brent and Sir John Dering. In the mix of intersecting ancestral lines, there are also ancestral connections to key names from the Wars of the Roses – eg Neville, Percy, Lancaster and York. 

Sir Richard Dering had Plantagenet ancestry via his mother Margaret Brent.  Margaret  was descended from John Of Gaunt and Edmund Duke of York who were sons of Edward III Plantagenet of England, and also descended from Henry III Plantagenet via his sons Edward I Plantagenet and  Edmund Crouchback.

Sir Richard Dering ‘s wife Margaret Twisden was a descendant of a Thomas Lancaster, but not the Sir Thomas Lancaster Plantagenet,son ofHenry IV BolingbrokeandMary de Bohun.

Sir Richard Dering married Margaret Twisden

The Dering – Fisher line of David’s 2020 DNA match is in the branch of the Dering – Brent – Twisden  family tree that can be traced back to Virginia in Colonial USA in the early 17th Century and is considered to be one of the early USA families. The profile of John Fisher (1603 – 1640) is one of the Gateway Ancestors of the Magna Carta project at Wiki Tree. John Fisher was also one of those listed in the 1623 Jamestown Muster. Some believe he arrived in Plymouth on the Anne in 1623, which was after the 1622 Massacre. However there is no complete list of the Anne‘s passengers – Wikipedia article, Wikitree, Great Migration Ships.  There are some claims that John Fisher’s sister Elizabeth Fisher had married Stephen Hopkins and they had arrived on the Mayflower. However I have not seen conclusive evidence linking Elizabeth Hopkins nee Fisher to John Fisher, son of Lady Benetta Dering.

Other triangulated DNA matches were suggested by Gedmatch with this latest match in 2020, but unfortunately, none had family trees extending as far back as this new match as of July 2020.

It is noteworthy that this 2020 DNA match, like the 2019 match, was in a quite different branch and was not connected to any of Daniel Dering Mathew’s Australian descendants. This, with that earlier match found in 2019, might support the supposition that Charlotte Johnson nee Oliver was Daniel Dering Mathew’s daughter. It will be interesting to see if any other closer matches emerge?David's Plantagenet Family 2020.07.14 v3 notesDavid's Plantagenet Family 2020.07.14 v3 

Note – As noted above, David shares his 13th great grandparents with this American DNA match. ISOGG’s Cousins Webpage suggests that the probability of there being no detectable DNA match between another descendant of your 13th great grandparent is 97.31%, ie there is in fact a very small probability of actually having a detectable DNA match. However the amount of DNA normally expected to be shared would be very small.

Certainly such a match with a MRCA (Most Recent Common Ancestor) being so far back was quite a surprise. FamilyTreeDNA has a table of expected cms for DNA matches for different degrees of cousins. Could it be a case of IBC (Identical by Chance) rather than IBD (Identical by Descent), and so be dismissed? Or could it be a case of Endogamy, ie pedigree collapse, given the very well known degree of intermarriages across the various Plantagenet ancestral lines of Daniel Dering Mathew, David’s 4 x great grandfather?  That intermarrying across about eight generations and some centuries of Plantagenet descendants from John 1 Plantagenet could certainly account for a fair degree of Endogamy. This has been well documented on various internet sites across the web. Also, both David and his 2020 DNA match have comprehensive family trees. And there did not seem to be other obvious possibilities for any other common ancestral lines from this July 2020  match’s family tree, as shown in Gedmatch, which might explain the DNA match. However surely it might be expected that over the last 200 years, that this possible Endogamous effect on DNA would have been well and truly washed out?

Impact of Endogamy Notes :

I encountered the concept of Endogamy in DNA when assisting an adoptee identify his bio ancestral lines – all from Tasmania as it later emerged. His closest match was a half first cousin at 1137 cms which I felt was huge. It really was well above the level suggested from Blaine Bettinger’s DNA shared CM project, ie where typically half first cousins might be expected to share 449 cms with a range of 156 – 979 cmsHowever the 1137 cms results was about 2.5 times the 449 cms level typically expected for half first cousins. When I queried this in a DNA forum, and indicated the adoptee’s bio heritage was all Tasmanian, I was advised that Endogamy was known to occur in some Tasmanian DNA matches.

Normally there can be a degree of confidence down to matches of 10 cms involving 5th – 8th cousins, especially where the matches also have family trees which point to MRCA’s Most Recent Common Ancestors. So it would be interesting to learn of the degree of confidence in matches of around 10 cms  where they involve matches more distant than 8th cousins and where a fair degree of intermarrying has occurred over generations over centuries, ie potentially Endogamous situations. At this stage I haven’t found too much information to answer this question. I have raised the issue of Endogamy in possible DNA matches of Plantagenet descendants in another forum. At this stage, mostly the responses were not so much science evidence based but rather opinions being expressed.

Perhaps in time, there may be more information available?

References on Endogamy

Other suggested descendants who went to Colonial America:

Edward, George, Twysden and Richard Dering – sons of Sir Richard Dering and Margaret Twysden? Also Francis and Philip Swann sons of Lady Amy Swann nee Dering ?

References on Plantagenets in the Americas

  • Elizabethan England Life  – suggests many people from prominent families left England and Ireland for the Americas during the time of English the Civil War and the execution of Charles I in England

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