DNA and Barrow Lousada genealogy

Our first exposure to DNA technology was when our distant cousin Michael Waas suggested some male-line Lousadas be entered into a study of male-line Sephardic descent. 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 (see also ref 306). Allan and Jeremy Lousada duly proved to be extremely close Y matches with a rare haplotype E-FT 333503 (derived somehow from the North African haplogroup EM35) while Bob Leuzarder (see below) was not a match (his haplotype is R-BY 193173 of the R1b haplogroup which is common among European males; the genealogical significance of this result is discussed below). On 21 Oct 2021 Adam Brown advised us of the next closest Lousada Y match - from Finland. This match has 33 out of 37 STRs in common with Allan Lousada; this is 4 genetic steps or about 300 years (9 to 12 generations) from birth of a common ancestor but the genealogical picture is currently inadequate to explain the match other than that a Finnish great-grandfather was 'Mediterranean'. 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 does not descend from the small number of original founders of the Ashkenasi community. But when Ed Barrow got his Y-DNA results back they placed him in the R-Y19847 haplogroup, and things got interesting. For as Michael Waas observed 'I briefly looked over the results and I can tell you that Ed belongs to one of our founding Ashkenazi lineages that also has been in the Jewish people probably since the beginning. I have brought Adam Brown in to the discussion for further information and detail. I didn't see any matches necessarily that descend from Simon Michael Pressburg; of course, if you know any direct Y descendants of him, we could test that theory..'. Ed's matches point to Myers and Wertheimer ancestors, and these families are present in the circle of Simon Michael Pressburg (see here).

 In the meantime, John Griffiths, descendant of Joseph Barrow, has proved inspirational in raising our interest in DNA. In late 2019 he compared his and Julian Land's autosomal DNA data on GEDmatch. It was exciting to experience this first match but it was insignificant (a single 3.4cM segment match on our 8th chromosome) and much 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. Randy Schoenberg provided access to his DNA records, and a number of matches with Randy Schoenberg were found. Further work on our Schoenberg matches (see here) was necessary to clarify the situation as discussed below. The de Symons connection might be expected to give single and double descendants of Simon Barrow of Bath a greater link to Randy Schoenberg and his ancestor Simon Michael Pressburg compared with those Barrow descendants like John Griffiths who do not have this connection. However, the situation is not quite so simple (see here) and our work raises the possibility that Baron Lyon de Symons may not be a biological descendant of Simon Michael Pressburg. 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'. Indeed, we have no certain knowledge of common ancestry - corresponding to our increasing certainty that Abraham Israel Pereira (an ancestor of Michael) did not have a Baruch Lousada mother but rather became by marriage a nephew of Isaac Baruch Lousada #42.

Some Fischl descendants made contact after seeing our Dirsztay Family Tree (ref 31). Dena Jenkins, with Fischl ancestry via Lajos Fischl 1798-1856, 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!' Though it is hard to see how this match with Dena Jenkins arose other than via Barrow ancestors, we were thankful that Scott McDougall's wife, with Fischl ancestry via Bela de Dirsztay 1861-1921, had her DNA results uploaded to GEDmatch. Autosomal matches were noticed and these became part of our set of data from probable relatives the analysis of which is discussed below. We are 7th cousins according to our Barrow/Fischl suggestion, with Simon Barrow's Baruch Lousada mother a common ancestor of her (and Dena Jenkins). A subsequent DNA match supports us here as it not only brings an additional Fischl link, but an additional Pressburg marriage link as well.

 In early 2020 Bob Leuzarder, who thought himself to be a probable descendant of Jacob Lousada a NY chocolate merchant, introduced some immediate relatives and also a DNA match also from the USA - Jeannine Wegmueller, a descendant of the Luzarders. It was not clear at first 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 multiple matches proving valuable. These 2 matches (on chromosomes 2 and 8 - the latter containing our first encounter with the unlikely segment boundary coincidence discussed below) appear to be indicators of Lousada DNA, and support our hypotheses - namely, both the Portuguese origin of Jacob and our Barrow/Fischl suggestion. Encouraged, we went on to hypothesize a descent of both the Luzarders and Leuzarders from Jacob, with Bob and Jeannine 4th cousins once removed. Also, we proposed that Bob ceased to be a male-line Lousada despite his surname, remarkably confirmed in 2023 when Bob reported a Y DNA match with Ernest Lloyd Luzadder; this match was of the R haplotype (that is, not the Baruch Lousada E haplotype, as noted above). This match links Bob like Ernest Lloyd to the great number of Midwest Lousadas who all descend from 'Aaron2' the namesake but not the son of Jacob's son 'Aaron1'. Nevertheless we considered whether Ernest Lloyd might have Baruch Lousada ancestry transmitted through a female line. We therefore updated our 7-relative study to include Bob and Ernest Lloyd (see here). This led us to increase the number of our candidate Lousada indicator segments from 2 to 4:

These indicator segments helped us develop the main structure of the genealogy of the USA Lousadas, with the placement of Ernest Lloyd Luzadder with most of the descendants of 'Aaron2' outside the Baruch Lousada genealogy (having none of the indicators), and on the other hand the placement of Bob (indicators Cr2, Cr5 and Cr21), Jeannine (indicators Cr2. Cr5 and Cr8) and a Papacin-Lousada descendant (indicators Cr2, C5, Cr8 and Cr21) within the Baruch Lousada genealogy. The latter tester was discovered by Bob Leuzarder after our 2023 8 by 8 study but her data was then included in our consideration of the Schoenberg matches referred to above; matches appear especially at the Cr2 indicator, but also at the Cr8 and Cr21 indicators. This demonstrates that Randy Schoenberg has a Baruch Lousada genetic link and raises the question of whether it is discoverable genealogically. Further work with the complete set of our probable Baruch Lousada descendants (a total of 12 as at July 2024) failed to discover any indicators distinguishing those with Barrow genes compared to those without. In Jan 2025, using the complete set of 12 probable Lousada descendants, and using Qmatch (3cM, P=7), we found no net increase in single matches with Ernest Lloyd despite almost doubling the Lousada match possibilities; this confirms our exclusion of him from Lousada ancestry whilst continuing to point to his non-Lousada links in New England (3 matches) and Europe (3 matches). Using Qmatch (3cM, P=3) with all 12 probable relatives, we re-affirmed the significance of the Cr8 indicator via 19 matches and 2 of the improbable segment boundary coincidences (see below), but we found the Cr5 indicator much less compelling and note that it played no role in the Schoenberg study just discussed and has no improbable segment boundary coincidences. That is, we now pay no attention to it, and observe that its absence does not suggest any change to our conclusions about Edward Lloyd Luzadder because the other 3 indicators remain functional. Naturally, we also reaffirmed the Cr21 indicator via 23 matches and 2 of the improbable segment boundary coincidences (see below). Though useful in our work, the indicators are not straightforward to use - thus, the absence of an indicator does not imply the tester is not Lousada and neither does the presence of an indicator prove Lousada descent.

Some instructive methodological points emerged. In our 7-relative study we included a sample of 7 nominally unrelated people so that we could contrast cousin-cousin matches with unrelated-unrelated matches. For this work, with a 3cM threshold, GEDmatch advised that 'segment threshold size will be adjusted dynamically between 200 and 400 SNPs' whereas this changed in our later 2023 8 by 8 study to 'segment threshold size will be adjusted dynamically with an average of 200 SNPs. About 2/3 will occur between 185 and 214 SNPs'. Initially we noticed that this GEDmatch settings change increased the number of matches between cousins as compared with matches between unrelated people, to the point where we got 5% more cousin-cousin single matches than unrelated-unrelated single matches (not fewer! - as with the prior GEDmatch setting). This is a 5% 'signal', which is small amid the 'noise' of all those pre-genealogical matches and/or false positives. But we noticed that, with the newer GEDmatch setting, the number of cousin-cousin coincident multiple matches increased strongly - by twice the increase in unrelated-unrelated coincident multiple matches (2 times cf 1.4 times as reported in our 2023 8 by 8 study) from which we can see why our version of John Griffiths' broad-brush analysis (of multiple coincident matches between relatives) had became more productive. GEDmatch advised that its Qmatch technique should give further improvement when looking at 3cM segments as we must with our 9-generation separations. But, even with the GEDmatch improvements, samples of unrelated people will continue to generate coincident multiple matches, and accordingly we continue to need ways of distinguishing useful multiple matches from pre-genealogical ones and ones based on any remaining false positives. We were lucky enough to find a specific type of segment boundary coincidence - a boundary SNP shared by 2 distinct pairs of probable relatives (that is, comprised of 4 separate individuals) - which is statistically very unlikely (around 1/7,000 based on rule-of-thumb estimates for our circumstances - 200 SNPs per segment, 30 segments per match, 1000 segments in the genome); it thus shows probable genetic connections between the 4 relatives despite not all meeting the criteria for being called matches at the settings chosen. We found such a segment boundary coincidence 3 times with our Cr2 indicator after finding our very first one with our Cr8 indicator (a number now revised to 2 as indicated above - these are 2 new cases as the original finding at 52269392 is only present in the form of a lesser coincidence at these settings), and 2 with our Cr21 indicator. GEDmatch did not offer a comment on our pointing out the significance of these segment boundary coincidences, perhaps because its segment boundary definition has an arbitrary element (for a segment boundary can be defined by the last SNP in a segment or the next SNP outside the segment) - though if the definition is consistently applied our logic is unaltered. In the CR2, 8 and 21 indicator matches all 12 Lousada descendants are present (Julian 17 times, JG 12, SW 13, Ed 15, Allan 12, RF 4, RM 11, Bob 10, Je 14, MD 4, TP 14 and Jeremy 8). Proven to be relatives by the 7 unusual coincident segment boundaries are 11 of these 12 (only Bob missing).

In Nov 2021 MyHeritage notified Julian Land of an 8*GGF who had been in Recife namely Aaron Querido #3161. This ancestral contribution enters via Baron Moses d'Aguilar whose wife Simha da Fonseca was a great-grandaughter of Aaron Querido as shown on geni.com based on work by Jarrett Ross. However Bob Leuzarder shares a 7cm DNA match with a person who descends from Aaron Querido a great-nephew of the just-mentioned Aaron Querido. This match appears to arise from Esther #1768, one of the Den Haag Louzadas, and perhaps Bob Leuzarder's match is the 1st present-day descendant of the Den Haag Louzadas we have encountered. Esther cannot however have been a direct ancestor of Bob Leuzarder, who has a different descent from Amador de Lousada who was Esther's 2*GGF. Remarkably Bob's sister Christine does not share the match, so the relevant genes were discarded from her DNA in the previous generation. Julian Land does not share the match either, but here the relevant genes may have been lost many generations ago.

On 10 May 2021, FamilyTreeDNA reported an interesting match Julian Land has with 3 successive generations of the Nunes Vaz family. Using the obvious point of linkage evident in Nunes Vaz ancestry namely Simha Henriques Faro #1629, we could not resist suggesting an earlier linkage between the Henriques Faros and the Baruch Lousadas than was deducible from the paper records. This was not entirely impetuous - we had been looking at ways further Henriques Faro links could have arisen. Jarrett Ross on 26 Sep 21 cautioned not only that there may be other Sephardic elements in the match, but that an Ashkenasi element is important as well because his GM (the 1st of the 3 generations referred to) is Ashkenasi! We interpret the matches as follows. Julian's match with the GM has been halved (as judged by the largest segment being halved) by the GM's marriage with a Nunes Vaz descendant. However, because total match was similar in the next generation, the missing Ashkenasi matching genes have been more or less replaced by matching Nunes Vaz genes. That is, there is a Sephardic match with the Nunes Vaz GF roughly comparable to the Ashkenasi match with the GM. In the next generation, the combined match has been largely preserved, probably because the matching DNA has largely survived (as judged by the largest segment not being much reduced), with only a small introduction of new matching DNA. While our original interest was the Sephardic match, the original Ashkenasi match is as close or closer than Julian's other Ashkenasi matches, and we explore it by looking at 3 common Ashkenasi matches but as summarised here, we can see some patterns but nothing of statistical significance.