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 the grandson of Simon Michael Pressburg - Baron Lyon de Symons - though the legal father of the wife of Simon Barrow of Bath may not be her biological father! 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. These became part of our set of data from probable relatives the analysis of which is discussed below. We are 6th cousins (once removed) 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 is somewhat supportive as the person has a marriage link with Lazar Fischl (4*GGF of Scott's wife), and an additional Pressburg marriage link as well. In early 2020 Bob Leuzarder introduced some immediate relatives and also a 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. With genealogical data so hard to find, autosomal DNA could not be dismissed, even though few people elsewhere bother with small segments of the size we were left with.

John Griffiths suggested trying to see whether segment match correlations could show underlying connections between relatives since individual matches at 3cM were unreliable. (His work showed over 200 DNA matches arising from a study group of 11 possible family members; John's last report #4 is here, and his observations on this are here). A later inspection by Julian Land of John's work - namely of the multiple segment matches arising from a subset of 7 of the relatives - is reported here with just 2 of 133 superficially intriguing multiple matches surviving scrutiny to ensure that these 2 were stronger than the types of multiples a random sample threw up. This is potentially a tough test in that there may be unknown genetic relationships within the random sample closer than the Baruch Lousada relationships we are seeking to confirm (see here), and indeed with members of the Lousada sample (see here and also the ELL discussion below). In any case the random sample, in this phase of the work, threw up surprising multiples (including both types of what we refer to as strong triples - 3 people matching each other, and 1 person matching 3 others). The chromosome 2 and 8 matches were the most impressive, since their strong triples were augmented by linked matches unlike the strongest random multiples in this phase of the study (which were bare strong triples). We were encouraged to hypothesize the descent of both the Luzarders and Leuzarders from Jacob a NY chocolate merchant (with Jacob assumed to be a great-grandson of Amador de Lousada of Vinhais via Amador's son Fernando and Fernando's son Henrique who was in Vinhais until 1650). In this, Bob and Jeannine appear as 7th cousins, but based on the genealogical situation of Bob's great-great-grandfather Benjamin (likely to have been the adopted son of a great-uncle also named Benjamin) we proposed that Bob was not a male-line Lousada despite his surname; this was 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 while excluding MW (see here). This led us to 4 candidate Lousada indicator segments on Cr2, Cr5, Cr8 and Cr21 (our collection of indicators was however to change over time with the latest candidates shaded in yellow):

Our hypothesized genealogy of the USA Lousadas places Ernest Lloyd Luzadder with most of the descendants of 'Aaron2' outside the Baruch Lousada genealogy (having none of these indicators), and on the other hand places 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. Bob appears in both genealogies! The Papacin-Lousada descendant was only discovered by Bob Leuzarder after our 2023 8 by 8 study but because of her probable Lousada genealogy (descending from the older Benjamin - see above) her data was then included together with 2 other known Lousada descendants (Allan and Jeremy - respectively 1st and 4th cousins of Julian Land) in  the Schoenberg matches referred to above; matches appear especially at the Cr2 indicator, but also at the Cr8 and Cr21 indicators. This illustrates that Randy Schoenberg probably has 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 now including Randy's mother and father) failed to discover any indicators distinguishing those with Barrow genes compared to those without. In Feb 2025, using the complete set of 12 probable Lousada descendants, and using Qmatch (3cM, P=7), we found that the increased number of single matches gave no enhancement of the inconclusive Ernest Lloyd multiple matches found with 7 Lousada descendants (Ju, JG, SW, B, Je, Ed and MD) on Cr2, Cr6, Cr12 and Cr13 as reported in our 2023 8 by 8 study, while creating 2 new inconclusive strong triples - on Cr1 (with none of the 5 new Lousada descendants) and on Cr21 (with 2 of the 5 new Lousada descendants). The 5 new Lousada descendants (RF, RM, Allan, J and TP) in fact generated only 19 additional single matches which is about half the rate of the older 7 who produced 49. The 3 strong ELL triples on Cr1, Cr12 and Cr21 showed inconsequential results when examined at P=3. This all confirms our exclusion of Ernest Lloyd from the Lousada genealogy. The Cr5 indicator played no role in the Schoenberg study just discussed and it now seems to be merely a type of multiple one can get with a random sample and by no means the strongest at these settings (cf the 2nd Cr1 multiple shown here). 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.  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 at an indicator prove Lousada descent (see here for an example where not only does a person from our random sample match many Baruch Lousadas at the Cr8 indicator, but she seems to have a non-Lousada genetic linkage with some of us of a strength comparable to the Baruch Lousada linkages we are seeking to prove!).

Further 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 the newer GEDmatch settings 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 5% 'signal' is of course small amid the 'noise' of all those pre-genealogical matches and/or false positives and suggests why we should be very critical in accepting coincident multiple matches as indicating relatives and indeed why there are so few of value. 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 11-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.

Luckily, 2 discoveries meet this need. The first discovery was of rare segment boundary coincidences (RSBCs) in which the same boundary SNP is shared by a pair of distinct overlapping pairs (that is, 4 separate individuals are represented at the SNP) - which has low odds (at around 1/750 based on rule-of-thumb estimates for our circumstances - 50,000 SNPs and 3 matching segments per chromosome). We first saw a RSBC (at 52269392) in the Cr8 match during our 7-relative study, and reported it in 'the coffee-table book'. Whilst this original RSBC is strictly not present at the Qmatch P=3 settings (as GEDmatch's Qmatch adjusted the left boundary of 2 of the matches by a small number of SNPs as shown here), most of the RSBCs we discovered on the Cr2, Cr8, and Cr21 indicators remain. They occur either on the left or on the right of the relevant pair of matches. The second discovery was of  'abutting segment boundaries' or ASBs which are a further type of segment boundary coincidence in which different matching segments abut at a SNP but otherwise don't overlap (we first reported 2 such cases here). The odds of this type of coincidence occurring by chance is the same (1/750) as for a RSBC. Initially we (mistakenly) saw an explanation of ASBs in meiosis, for 4 gametes are produced from one set of parental chromosomes. Complementary gametes show a parent's DNA rejected on one side of a recombination appearing on the other side, thus producing an abutting boundary coincidence which can survive to later generations. With some excitement our presentation 'Fun with Autosomal DNA' used this 'insight' to claim a Baruch Lousada connection across 4 family branches. However Andrew Millard pointed out that the statistics of sperm and egg utilization do not favour our 'insight'.

Back then to the hard work. All 1962 segment matches - mostly false positives of course - generated by Qmatch (set at 3cM, P=3) from our 12 relative sample were laboriously collated. From this we found a total of 41 rare segment boundary coincidences (RSBCs), 22 lefthand and 19 righthand, and most were new to us. Also, 15 new ASBs were discovered making 17 in total. In each category - left RSBC, right RSBC and ASB the expected number occurring at random is much less than 1 (the estimate is 0.09). This estimate is of course related to the underlying unlikelihood of RSBCs and ASBs, and suggests family connections must be the causal factor behind their excess incidence, despite there being too few SNPs for conventional genetic genealogy. The 41 RSBCs are mostly associated with locations rich in matches and indicator sites. At each of the 41 sites there are many false positives, so strong corroborating evidence is also needed. This led us to 14 small but genuine matches, which unmistakably interconnect 11 relatives, with 5 of the relatives doing the bulk of the work - SW, RF, RM, Je and TP. Thus, as we somewhat prematurely claimed in  'Fun with Autosomal DNA', the New England Lousadas are indeed related to the English Baruch Lousadas and the Barrows, while so is Scott's wife and hence the Fischls. Randy's parents are also related. MD was not connected by RSBCs alone, but ASBs were needed (see next paragraph). Finally, this work led to the identification of (the 7.1- 8.1m region of) Cr18 as another indicator for with 4 lefthand RSBCs and 2 righthand RSBCs it is better qualified than the original Cr2 (4 lefthand RSBCs and 1 righthand RSBC), Cr8 (4 righthand RSBCs), and Cr21 (2 righthand RSBCs) indicators. Other possibilities are the 58m-59m region of Cr20 (which has a lefthand RSBC and a righthand RSBC) and the 18.2m - 19.2m region of Cr22 (which has a lefthand RSBC and 4 righthand RSBCs). Currently we favour those indicators in a rich region and having both left and right RSBCs - on Cr2, Cr18, and Cr22.

Our small match procedure is described here, in which as an illustration we use our 12-relative set with 14 proven matches derived from RSBCs and 24 proven matches derived from 17 ASB locations - noting as we explain here that the useful type of ASB is the more numerous and statistically significant 3-relative version, and not the less common but statistically less significant 4-relative version. This is the reverse of what happens with RSBCs, where there is a common 3-relative version which our definition of RSBC excludes, and which is worthless (genealogically speaking). Showing the importance of the MD case, we list which of our 12 relatives descend from different sons of Amador de Lousada:

• Allan and Jeremy (also Julian) - David #1584, Isaac #42 and Abraham #2149

• Bob (also Jeannine, TPhelan) - Fernando #1785

• John (also Ed, Scott's wife, Randy's parents) - Isaac #42 and Abraham #2149

• Mike - David #1584

 Now we have proof that David #1584 was part of the Baruch Lousada ancestral family. Until then, we relied on our (sketchy) genealogical work to conclude that David #1584 was also a brother. Thus Isaac #42 appears to have married the widow of David #1584, making David's sons Aaron #376 and Abraham #1875 stepsons - with the later son Abraham #1875 born legitimately into Isaac's marriage; and then in Amsterdam, believing he was the son of Isaac #42 (who was in Livorno at the time with a new wife having lost his first wife the mother of Abraham #1875), he named his son Isaac whom we know as Isaac #50. On the other hand, Isaac #42 (knowing he was not the biological father of Abraham #1875) went on to have his own son Abraham whom we know as Abraham #45. On his part Aaron #376 did not suffer the same misapprehension as his biological brother Abraham #1875, for he named his first son David (after David #1584) and only a later son Isaac (who died in infancy). That David #1584 was a brother receives an additional DNA echo as follows. 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-granddaughter of Aaron Querido as shown on geni.com based on work by Jarrett Ross. However Bob Leuzarder shares a 7cM DNA match with Dagmar Querido Sullivan (dqs1) a person who descends from Aaron Querido a great-nephew of the just-mentioned Aaron Querido (being a grandson of Abraham Querido a brother of the first Aaron). This match appears to arise from Esther #1768, one of the Den Haag Louzadas, who was not a direct ancestor of Bob Leuzarder as Esther #1768 was biologically descended from David #1584, being her GGF, and not his brother Fernando #1785 (Bob's ancestor). Bob Leuzarder's match is our first contact with a present-day descendant of the Den Haag Louzadas. 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. The descent of dqs1 from Esther #1768 is shown here where it will be observed that Esther #1768 married Jacob de Mercado in 1691 and had a daughter also Esther (born 1702) presumably named after the paternal grandmother. Only one such Esther may be found in Amsterdam records - she became the wife of David de Mercado in 1656 - so presumably Jacob de Mercado was the son of David #2405.

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.