Has Y-DNA disproven the father of Louis-Philippe Langlois dit Serien?

Question

One of my ancestors, Louis-Philippe Langlois dit Serien, was an English man from Boston who married Marguerite Lavoye in Rivière-Ouelle, New France in 1718. His parents are not named in his marriage record.

A popular theory is that he was the same person as Daniel Sargent born about 1699 in Worcester, son of Diggory Sargent, who was re-named and baptized as Louis-Philippe Sargeant in Montreal in 1707. It's been suggested they are the same person because the names Sargent and Serien are a little similar, and it fits with Louis-Philippe being from the Boston area.

There is a Sargent surname Y-DNA project on FamilyTreeDNA, and some descendants of Louis-Philippe's only son have tested as well as some descendants of the suspected father Diggory Sargent's other son John Sargent:

https://www.familytreedna.com/groups/sargent/about/background

https://www.familytreedna.com/public/Sargent?iframe=ycolorized

While both sets of descendants share haplogroup R1b1a2, the project notes that the descendant groups "do not match the first 12 markers". When I compare the 67-marker tests of the two groups there are differences in 21 of the markers. 

I'm not very familiar with Y-DNA testing. Does this prove that Louis-Philippe Langlois and John Sargent were definitely not brothers (assuming the test-takers trees are accurate)?

Strangely, the Louis-Philippe descendants do seem to match a different Sergeant man from Boston: Samuel Sergeant (1744-1773). 

Any thoughts or comments would be appreciated!

Comments

Samuel Sergeant b. 1744, who m. Bethany Smallidge of Boston were my 5x great grandparents. I have documented with Church baptismal , marriage, and land records  and so many other documents to tie back to parents Thomas b 1705/06  & Elizabeth (Tomson) Sergeant and then further  back to Thomas Sergeant & Ruth Johnson(1665),(daughter of Francis Johnson Jr b 1644 and unknown mother who I beleived were living in Marblehead, Ma before the Muscongus/Long cove area in Maine.  I have spent at least 30 years on the documentation, But there has unfortuantely not been a great deal uncovered in or abt 1659/61 Maine or how Thomas got to Maine or where he came from , or his parents. , He was awarded 1oo acres from then Gov Thomas Dongan, Much of the documentation on the couple was gleaned from The Genealogical Dictionary of Maine & New Hampshire, There are still a few Sergeants unaccounted for, and I hope to solve this  sometime.  but I was certain the YDNA thread may solve the tree, which made the puzzle so much more difficult. My mother was the Sergeant, so I talked her brother (before he died) to submit the YDNA Kit , Please email me if you had any suggestions. Please remember many of the settlers did not actually live at the Fort Pemaquid but used it for protection. The Tax record from Andros says Francis Johnson Jr, Thomas Sergeant, and Thomas Wardin/Warden(who married Mary Johnson, Ruth'Johnson's sister & lived near Long Cove near the Muscongus River a few miles from Fort Pemaquid
Penny Kresl (pennykresl@charter.net) if you wish to collaborate. Maybe we can help one another? Denis Savad has been a wonderful help.

Answer 1

Hi, Valerie. The absolutely crucial point is one you described: "assuming the test-takers' trees are accurate." I admin a few FTDNA projects, and that's always the bottom line: the paper trail. Unless there's the opportunity to directly analyze remains--for most of us, slim to none--we're always left with trying to figure out who is actually descended from whom.

With yDNA, since there is no recombination during meiosis in the majority of the chromosome, the part we compare, people familiar with using autosomal DNA can sometimes be confused by the term "genetic distance" as applied to yDNA. Results on the Y chromosome can't be predictive of relationships in the same way that autosomal DNA can, so "genetic distance" has no direct correlation to the number of generations separating individuals; instead it references simply the number of assumed, independent mutation events that have taken place based on the STR (simple tandem repeat) counts.

Looking at the Sargent DNA Project, I gather that it's Lineage 01 and Lineage 05 that we're talking about. FTDNA switched several years ago from a purely stepwise count of STRs to what's called the infinite allele model; all that really means is that some variation counts, particularly in STRs that display multiple values (like DYS459, DYS464, YCAII, etc.), are given a little slack because more than one change might have occurred in a single generation.

A quick and admittedly cursory look at the modal values for Lineage 01 and Lineage 05 show me a genetic distance of 15 at 37 markers. FTDNA considers anything beyond 4 a non-match at that level, and I believe even that is lenient. In my Williams subproject, we have multiple men who are a genetic distance of 4 at 37 markers who we know, based on the full sequencing of the Big Y test, cannot be related until circa 900-1000 AD. In other cases, a GD of 4 at 37 markers might apply to men who are separated by 10 or 12 generations from their MRCA. But a genetic distance of 15 is considered a non-match if even 111 markers are being evaluated.

It looks as if no one in either Lineage 01 or Lineage 05 has taken the Big Y test, so the basis for analysis is limited. But it's extremely likely that the common ancestor between those groups would date back thousands of years; no biological relationship at all within the genealogical timeframe.

Comments

Thank you Edison, that answers my question. 

So now we are left with this conundrum: the Y-DNA points to descendants of Louis-Philippe matching with descendants of Samuel Sargeant, indicating that Louis-Philippe did indeed have the English surname of Sargeant, just like we suspected, but it is not clear how he and Samuel are related.

It's possible that there are errors in the trees of either the descendants of Louis-Philippe or the trees of the descendants of John Sargent. A brief look didn't uncover anything obvious.

It seems strange that he would have descended from a Sargeant, and yet not match the 1707 baptism record for Daniel/Louis-Philippe Sargeant. But there is some other evidence to suggest that Daniel, the son of Diggory Sargeant, died in Canada unmarried before 1728 while Louis-Philippe Langlois was still alive.

In any case, I think there is enough mystery around this man to change his mother and father to "uncertain" and add some of this discussion to his research notes.

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To be sure, the Langlais lines were verified by professional genealogists and Louis-Philippe's is triangulated (and matching the Maine Sargent line):
http://francogene.com/triangulation/TRI0044.php
Digory and his wife should absolutely be removed as his parents. The Langlais descendants do not match the Digory Sargent's line which has multiple descendants tested who all match (once the Langlais claims are removed).
https://www.familytreedna.com/public/Sargent?iframe=yresults
Although no Big Ys have yet been taken, the genetic distance between the two lines is too great to call it a match by any measure. And at that distance, genetic drift could easily hide an even more distant relationship... The quantitative data however rules out any possible "closer than it appears" relationship (the two clusters are well enough defined and too far appart):
 

On the less sure side of things: I personally believe Louis-Philippe is the son of Thomas SARGENT & Ruth JOHNSON born in Fort Pemaquid and taken in the 1689 attack. Only a few names are identified from that attack. Despite being apparently married for as much as 8 years at Fort Pemaquid, where the Johnson's were early settlers, their first "known" child in only born in 1690 in Scituate, after their removal from Fort Pemaquid (and its attack), which is very suspicious. This is of course still conjuncture. In this scenario, Samuel would be a grandson of Thomas through likely Thomas jr & Elizabeth Thomson. 
 

Note: on the triangulation link, D Beauregard added by mistake, Benjamin as father of Louis-Philippe. This last generation was speculative, and I believe wrong. I think the capture associated with this family is too late for Louis-Philippe to work out his servitude and gain his freedom. He is bought out from slavehood after all... 

There is no known connection between Benjamin and Samuel (DB assumed there was), and they are apparently from two different Maine Sargent stock (the former family being more around the Saco river). But none from the Benjamin/Lt John of Saco/Stephen of Richmond Isle line have yet Y-DNA tested to confirm or infirm this. 

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Thank you for the input Denis. Yes the profile manager also thinks that Digory Sargent and Mary Oben should be removed as the parents. So we will work on that and changing the biography. And of course, you should feel free to contribute to Louis-Philippe's profile too since it sounds like you know quite a bit about him.

That is an interesting theory about Thomas Sargent and Ruth Johnson. It does seem likely that Louis-Philippe came to Quebec when he was young enough not to know the names of his parents, since they are not named in his marriage record or marriage contract even though his bride's parents are named.

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There is a Facebook group that goes over the state of research in this case. I don't know how appropriate it is here, but was in lieu of a paper on the matter until key pieces (i.e. parents) can be put in place. We are still at the speculative and conjuncture stage. Perhaps the profile manager can pick and chose - citing the group - what is more relevant as clues to research leads... under a Research notes section. I'd gladly write up a summary but I am starting a move and don't know when I can get to it. 

https://www.facebook.com/groups/LanglaisSargent

Answer 2

I was comparing autosomal DNA from three of Diggory Sargent's children. Mounger-571 related to Martha, Perkins-10289 related to John and myself Larouche-239 related to L-P Langlois aka Daniel Sargent. Sharing with each other around 140cM. One would think this would raise the confidence level. But then I tested them with my sister Larouche-242. They are all sharing X-Dna with each other. What make this impossible is that they all have father-son relation in their lineage. Which brings even more questions. Was there adoption? Does the relation go even farther back in time from Ireland or Scotland? Dna will one time tell us who it is.