Estimating variance based on family DNA

So I'm still curious about the DNA results...

I'm thinking that the lack for French ethnicity might be due to a weird roll of the dice in terms of the DNA makeup I inherited from my father and mother.   Part of this comes from comparison to a first cousin: we share the Bradish/Guimond side of things but his mother's side of his family is far removed geographically from my father's side of the family.   Yet he comes up with 11% French, whereas I come up with 0%.   Since the overlap is on my mother's side, I think I can safely preclude any "Jerry Springer"-esque explanation.  :-)

So - how to model this?   It occurred to me that getting DNA samples from my father and sister (or brother) might be enlightening.

For my father, there should be roughly 50% overlap (from a zeroth-order assumption).  So anything that doesn't overlap comes from my mother.   If the overlap is far more than 50% (and I'm not a biologist so i don't know if this is a valid hypothesis) then - borrowing from Game of Thrones - "the blood is strong" and genetically, I'm more Irish than French.   I'd expect that my father should come out almost exclusively Irish with some English.   But for my siblings, I suppose anything is possible in terms of the Irish/English/French ratios (unless my hypothesis is entirely invalid).

In the case of my siblings, they should also have roughly the same 50/50 split (as a base assumption), but with different overlaps.   Quantitatively, the difference would be some kind of estimate of the variance within one generation of "shifting" - in other words, "you have your father's nose, but your mother's eyes" might apply to one child, but the opposite for another. 

So, if there's X% variance between siblings, then that effect gets multiplied as you go back in time, complicated by the additional consanguine relationships with in-laws with the eventual "genome collapse" that happens when those family lines intersect from a shared common ancestor.  (The math for that might be completely impossible to do - but I think it would be a fun challenge!).

I also have to wonder to what extent the rabid genome researchers would love to sample the DNA from these ancestors.  Aside from the nasty thought of "grave robbing DNA", it would be extremely interesting and could solve some mysteries.   The biggest dead-end on my mother's side is her great-grandmother Célina Boulé:  was she adopted?  Who are her parents?  It's extremely likely that she is also a distant cousin from some blood line, but I think I've successfully ruled out the handful of "possible relationships" that others have used on their family trees. 

There's also the intriguing -- though I think unlikely -- possibility that she isn't Québecois at all.   Apparently there are cases of Irish children fleeing the potato famine being sent to North America.  Perhaps she's one of them - which would also inject Irish ethnicity into what otherwise would've been a nearly 100% French genome, for me only 4 generations back (so 1/16th overall but 1/4 of the Guimond line).   If it's also true that she was adopted by Moïse Boulé and Domitille Bernier it might make since since as far as I can tell they had no children of their own. 

I have two hopes:  1) that I can get some breakthroughs on my father's side of the family.  Finding a few bona-fide third or fourth cousins might open up some avenues;  2) ditto on the Guimond side, in the hopes that eventually we solve Célina's past.

DNA results - part 2 - distant cousins

So one of the OTHER "features" of the DNA testing is that it's supposed to help you identify potential distant cousins based on likely common ancestors.

From the Ancestry.com side of things, this is something of a bust too.   At least for me.

I've got 55,000+ people on the family tree.   But there are several dead-ends - especially on the Irish side and on the Bradish line.   So I was hoping to find others who might be able to provide a breakthrough or two.

Ancestry has identifed ~250 people with whom I have a shared ancestor.   However looking at their profiles, they fall into three categories:

1. People who took the DNA test but haven't done their family tree - no help there;
2. People who started on their tree but it only has a few (e.g., 10) people on it - no help there;
3. People who have fairly large family trees.  YAY...  but hey - their entries use the same format I do for names, etc...

... oh dear - their family tree is based mostly on getting data from another tree...   Mine!

Oh well  :-)

But there is one first-cousin whose tree has a different set of parents for John Patrick Bradish (the great-grandparent who was born in Punjab) and they're Irish not English.   This changes the Ethnicity assessment (skewing from mostly English to mostly Irish).   The parents I have came from Google search, are VERY low-confidence, and relied on the assumption they'd be English (since he served in the British army).   Although Ireland was part of Great Britain at the time, it just seemed to me to be unlikely many people would enlist in the British Army from Ireland.   But that might not be a valid assumption at all, and even if it were, it doesn't mean that this is an exception to the rule!

Something to follow up on!

DNA Result are in... What the hell?

So I get my Ancestry DNA results.

• 59% Ireland/Scotland/Wales 
• 32% Great Britain
• 8% Other

I expected:

• 50% English (based on the Bradish/Murphy and the Hall/Murphy lines, but see the next posting)
• 25% Irish (Donahue line)
• 25% Frence (Guimond line)

Where's the French?

Now all the Ancestry DNA ads have some kind of "Find Exciting Surprises" where someone takes the test thinking they're an Italian/German mix and discover they're 80% Russian and 20% Japanese or something like that.

But the largest chunk of my family tree that's mapped are Québecois - and I have HUNDREDS (probably a few thousand at this point) of original settlers who were born in FRANCE.   Now I know SOME of them started out somewhere else, went to France and from there went to Québec.   I know that some of the immigrants came from England, Ireland, Germain, Switzerland, Spain, and Italy.  But not THAT many.

I don't know what to make of this.   We've joked that there's some kind of "Jerry Springer" episode in here somewhere "you are NOT the father" - except that it would have to be "you are NOT the mother" and that would be difficult to pull off since surrogate motherhood is definitely more of a 21st century occurrence.

But there are other possibilities.   The Ethnicity estimate comes from where your current-day relatives who have taken the DNA test reside NOW.   So one might expect some degree of variance from that.  EXCEPT that one could do the appropriate weighting based upon coverage of test subjects versus actual population (and they have to do this I think, otherwise NO ONE's results would be accurate).

There's also the fact that one doesn't necessarily inherit the same degree of genetic material from EACH ancestor proportionally.   Perhaps "the blood is strong" (to quote John Arryn) is in play here, and just that my paternal contributions to my DNA overtake the maternal.   

So I think I'll splurge and get a comparison test with 23andMe.   I'm also wondering if I can convince dad or a sibling to also do the test so that we can compare.

Hey! Wait a minute...

So I'm knee-deep in Acadians.   The records are tricky because once the English invaded and started forcibly removing them, they moved around.   A lot.

Many escaped to Québec, others ended up back to France.   Some settled elsewhere in the Saint-Lawrence River islands:  Miquelon, Prince Edward Island, the Iles-de-Madeleine, etc., and some went to other French colonies: Louisiana, and the Caribbean (Haiti, Guadeloupe, etc.).

But many ALSO went to the (now) USA:  Boston, the Carolinas, Georgia, and so on.

This doesn't make any sense to me.   If you've just been invaded by a foreign empire, why would you travel to that empire's colonies? 

But there's a simple explanation --- tt turns out that this was actually the British government's doing; at first they "relocated" Acadians to the British Colonies, to rural parts of Massachusetts, New York, and so on.  However this cunning plan didn't work out the way they wanted:  the Acadians refused to stay and just to the cities forming Francophone communes or tried to get back to Canada (which is exactly what the British did NOT want to happen).   So, the second wave of deportations were made to France instead.

From THERE, many once again moved - this time from France either back to the St. Lawrence River settlements, or south to the Caribbean and Louisiana (which I just learned came under Spanish control in 1762 - I really need to bone up on this history).  Some even went as far as the Falkland Islands! 

I've also noticed that many died shortly after leaving Acadie.   The records in Québec are rife with burial of Acadians in 1759.   But I'm also finding similar spikes in deaths in France among the repatriated Acadians.  (Some others apparently died at sea trying to get to France.)

Phase 1 1/2: The Acadians

So, I've got about 25-30 Acadian familes (from generations 8 to 15) to do.

Not sure how successful this will be because there isn't quite the comprehensive indexing that there is for the Québec familes: some of them are in the PRDH, but typically not in Lafrance, although many are also in the GQAF.

The canonical material is from S.A. White published in 1999 but out of print.  A revised 10-volume set is in preparation but with no projected date of release.

• More info and a short background

So - was my estimate right?

Way back when (May 2015), I estimated the number of great-aunts/uncles and 1st cousins N times removed there'd be in the tree based upon a calculated average of 5.8 children per family.

What I came up with was 1,673 aunts/uncles (when I started the project).   It ended up being 2,184.

Why the difference?   Some thoughts:

1. The estimate was based on my mother's side of the family only.  Now while my father's branch of the family tree is meager in comparison, it does add a few dozen people.
   
2. The estimate was based only on generations 3 through 10.   I actually ended up working out to generation 13 (although far from complete). 
   

So - now that I've done the 1st cousins N times removed (8,245 of them) - that ends up being short of the expected 9,760.   Why is that?

Two things, I think.   First in the estimate going from direct ancestors to aunts/uncles, we KNOW that each of them were married (they're grandparents, after all) whereas there's no guarantee that every child who is an aunt/uncle will also have children (some die early, others never marry, etc.).   Another effect is that single-marriage families might have children over a period of 20 years or more, multiple marriage families have a shorter window, which means fewer children per family.

Without looking at every aunt/uncle and removing all the cases where there are no children (code which I could write I suppose), getting an accurate measurement from the aunts/uncles to 1st cousins to estimate the family size for 2nd cousins would be difficult.

In any case, the ratio of 1st cousins to aunt/uncles is 3.8 instead of 5.8 which is essentially an "effective" family size (i.e., counting non-married people in as a family size of zero).

So - I suppose to zeroth-order, the estimate number of 2nd cousins (the C:X,3's on the tree) should be about 31,000 people.  Given that I seem to be able to add about 10K people/year,  I guess we should expect the next report on this to happen in Spring 2021.   :-)

Ancestry DNA kit was sent off 2/26.   Should come back in about 3-4 weeks.

My guess - based on what I have on the tree:

1. About 50% English
2. About 25% French
3. About 25% Irish

Depending on how far back it gets, I expect to see some Viking, some Native Canadian, and some other central Europe (Germany, Spain, Italy).

What would be VERY interesting would be if this in any way helps me crack some of the dead-ends.

I guess we'll see.