DNA and Barrow Lousada genealogy

Our first exposure to DNA technology was when our distant cousin Michael Waas conducted a study of male-line Sephardic descent in which some of us participated (see ref 306). This study was drawn upon in early 2020 by his collaborator Adam Brown when he covered the use of Y-DNA data in Jewish genealogy - paper uploaded here. Adam Brown also, in the online discussion group Sephardic Diaspora during 2019, referred to the Ashkenasi founder effect (see here) and to the likelihood that Randy Schoenberg (and presumably all of us who descend via the Barrows from Simon Michael Pressburg) does not descend from the small number of original founders of the Ashkenasi community. This discussion is ongoing - but perhaps the ancestors of Simon Michael Pressburg included people from the Sephardic Diaspora. We are exploring with Adam Brown a Y-DNA mini-project using advanced analysis technology and a small number of male-line Lousadas. In the meantime, Julian Land and Michael Waas compared their autosomal DNA and as Michael reported on 25 Jan 2020 'we do have some very small 3cM segments shared between us. But who knows if that's from the Portuguese or Ashkenasi sides of our families'. Of course their total autosomal match of 16.2cM is perhaps a little high but certainly not a statistically significant abnormality for 10th cousins, but allows for other connections as well.

John Griffiths, descendant of Joseph Barrow, has proved inspirational in raising our interest in DNA. In late 2019 he matched his and Julian Land's autosomal DNA data on GEDmatch and found that we have a single 3.4cM segment match on our 8th chromosome. This match is less than might have been expected for 6th cousins (common ancestors Simon Barrow 1709-1802 and Bailah Montefiore 1720-73) but probably illustrates how drastically autosomal DNA can be discarded. Then, Randy Schoenberg having provided access to his DNA records, John Griffiths and Julian Land found matches with Randy Schoenberg, with one segment match on the 21st chromosome being common to all 3 people. But the failure of this 21st chromosome segment to show up in the comparison between John Griffiths and Julian Land presumably reflects a match of their 21st chromosome fragments to different half-identical regions of Randy's 21st chromosome (see ref 313 pp154-5). Thus at least one of John Griffiths and Julian Land has an independent non-Barrow link with Randy Schoenberg. However, total matches with Randy were 16.2cM and 28.1cM respectively, matches which correctly reflect Julian Land's greater link to Randy Schoenberg (because of the de Symons connection which all descendants of Simon Barrow of Bath have and which therefore John Griffiths does not have), while Julian Land's residual connection plus John Griffiths' own substantial connection suggests a direct Barrow/Pressburg link (the proven non-Barrow link was 3.0cM). Nothing needs to be explained in connection with the failure of Randy Schoenberg's DNA to show the 8th chromosome match - this part of his DNA has been effectively discarded.

To this may be added what we have learnt from autosomal DNA analysis of some Dirsztay descendants. An anonymous correspondent with probable de Dirsztay ancestry found on FamilyTreeDNA that 'hooray we have the same 5th cousin. I found him in your kit and then went on my cousin's kit .. we both have him....If we both have the same 5th cousin we must be related!' However this match with our anonymous correspondent may have arisen other than via the Barrows, and in any case her implied relationship with Julian Land equates to that of 5th or 6th cousin which may not prove compatible with the 7th cousin predicted by our Barrow/Pressburg suggestion extended to include the Italian origin of the Dirsztays. In the absence of further DNA comparisons from our anonymous correspondent, this connection has not been further examined, and we have been most fortunate that Scott McDougall's wife, a descendant of Bela de Dirsztay 1861-1921, has had her DNA results uploaded to GEDmatch, and autosomal matches with Julian Land (23.2cM) and John Griffiths (20.3cM) confirmed. Her matches with us are what might be expected for the 7th cousins we probably are according to our Barrow/Pressburg suggestion, and thus we continue to regard Simon Michael Pressburg as a common ancestor.

 In early 2020 Bob Leuzarder, who thought himself to be a probable descendant of Jacob the NY chocolate merchant, introduced some immediate relatives and also a 29.8cM DNA match also from the USA - Jeannine Wegmueller, a descendant of the Luzarders. It was not clear how the Leuzarders (see here) and the Luzarders (see ref 314) related to each other nor to the rest of us. They participated in the work by John Griffiths on over 200 DNA segments arising from a study group of 11 likely family members; John's latest report #4 is here, and his observations on this are here. A later inspection by Julian Land of the DNA segment matches arising from a subset of 7 of the relatives is reported here with just 2 of 133 of these superficially intriguing matches proving valuable. These 2 matches (on chromosomes 2 and 8) represent antique DNA, but only serve to elaborate (rather than to prove outright) our hypotheses - namely, the Portuguese origin of Jacob and our Barrow/Pressburg suggestion. Nonetheless encouraged, we went on to hypothesize a descent of both the Luzarders and Leuzarders from Jacob the NY chocolate merchant. In this, we show Bob and Jeannine as 4th cousins once removed, and Bob ceasing to be a male-line Lousada despite his surname. Bob Leuzarder and his close relatives were not included in Julian Land's 7-relative study so it was a pleasant surprise when they turned out to have the antique chromosome 2 Lousada segment identified therein. But there are a few somewhat more awkward implications flowing from our hypotheses, adorned as they now are by DNA. For the chromosome 2 Lousada match also shows that Jeannine has a non-Lousada match with Scott's wife, while the chromosome 8 match shows that Ed Barrow has a non-Lousada match with Jeannine. Added to this is that striking match noted by John Griffiths between Scott's wife and Michael Waas. Hopefully this tension can be productive, for we note that the Dirsztays were a prosperous family, presumably with many offshoots into Europe, the New World via Amsterdam or Livorno, and the Ottoman Empire; but the link between Ed and Jeannine could be Irish.

The matches Bob and Jeannine have with Julian Land (at 27.6cM and 31.8cM respectively) are surprisingly similar to their own match, but there is high degree of consanguinity present - there may have been one or two more earlier cousin-cousin marriages in each line, additional to the cousin-to-cousin marriage in 1833 in Bob's ancestry plus a probable uncle-niece marriage in 1698 in both Jeannine and Bob's ancestry together with 2 cousin-cousins marriages in 1832 and 1743 in Julian's ancestry. Julian and Ed Barrow are 4th cousins and their 31.2cM match may be somewhat enhanced due to consanguinity - the 1832 cousin-cousin marriage in Julian's ancestry. A summary of the total autosomal DNA matches of 8 relatives can be found here, though it should be noted that in this summary we have used a tighter SNP filter and as a result the matches noted above are higher than they appear in the summary. We have used some nominally unrelated people in our summary so that we could contrast cousin-cousin matches with cousin matches with the unrelated people (who turn out to have some interesting connections anyway)!