MITx offers a wide range of free, on-line, self-paced semester-long courses to anyone in the world. Coming up next week is Introduction to Biology – The Secret of Life. I’ve taken this course (actually twice). It’s taught by Professor Eric Lander – the founding director of the BROAD Institute and a principle leader of the Human Genome Project – and a fantastic instructor (his course is fun). This course is targeted at non-biology students. This is not about genealogy, it’s about DNA. Anecdote:  I was about halfway through the course, and one night my wife called out: “Jim, what are you doing – it’s 3 AM.” My reply: “I’m in a lab, folding proteins to capture a virus”.  If you are into DNA and Segment-ology, this is a great opportunity to get a firm grounding.  As a side note, I think MITx is a great undertaking and am a regular donor to that program. Free, world-wide MIT classes…

Here is a link: https://www.edx.org/learn/biology/massachusetts-institute-of-technology-introduction-to-biology-the-secret-of-life

Click on the short YouTube video… Enjoy.

[99D] Segment-ology: MITx Class on DNA is Free by Jim Bartlett 20250128

Small Segment Stats

Ancestry DNA Matches who share 6-7cM and have a known MRCA with me: 1,160.

Total Ancestry DNA Matches at any cM level: 7450.

About 15% of my DNA Matches with a known MRCA share only 6-7cM.

This is NOT a statement linking DNA and Ancestors.

This IS a statement about the many true cousins we will not see in our Match lists because the current threshold at AncestryDNA is 8cM.

I’m glad I Dotted and saved some of my 6-7cM Matches when Ancestry made the threshold change – it was a fraction of the total. I wish I’d have saved them all…

To end on a higher note – I still have 2,600 other 6-7cM Matches to work with – many of them are being determined as close cousins to known MRCA Matches by using ProTools.

[22DF] Segment-ology: ProTools Part 24 – Small Segment Stats by Jim Bartlett 20250221

Integrating With Genealogy

ProTools is a powerful tool. But it has it’s limits. 1C and closer relationships are very accurate, in my experience. Beyond that, the range of possibilities grows quickly as the cMs fall below the 1C range. But think about what that means… A 1C relationship takes us back to our grandparent level. Think of a 20 year old genealogist with a 50 year old parent, and 80 year old grandparents. Those grandparents would be in the 1950 census. And the census is a pretty good tool back to 1850 – another few generations. You might argue that the census is not rock solid in every case. There may be adoptions, NPEs, etc. That is true, but those individuals will not show up as DNA Matches – for the most part.

Yes, there are still a few situations that may slip through. But on the plus side, the census and ProTools will sort out a high percentage of false relationships, and/or incorrect genealogy “research”.

Used together, the census and ProTools can pretty accurately cover the past 175 years.

[22DE] Segment-ology: ProTools 23 – Integrating With Genealogy by Jim Bartlett 20250131

A Rant about Relationships

I praise Ancestry for ProTools – just about everything about it is great. I have often reported how accurate the close Relationship Estimates are. I rely almost 100% on 1C and closer relationships; and have found many 2C relationships to be correct. I worked for several days on a 3C relationship – knowing the Trees of the two Matches pretty well – to no avail. This is becoming a regular occurrence.

I’ve noted over the past year, Ancestry has tightened up their Relationship Estimates – all are now within 4C. We can tag a Match at 4C or closer, or Distant. A far cry from the Circles where Ancestry showed us how we were related out to 8C; or even the current ThruLines out to 6C.  Will they change again, tomorrow, to only showing Matches related within 4C or closer? I am long since past that threshold…

So I decided to take a deeper dive, under their hood, to see what they predicted for small cM Matches. I randomly selected a 6cM Match that I had saved. She was predicted to be Half 3C1R or 4C – evidently their deepest estimate. So I clicked on that estimate to get their more in depth analysis. Here are two screenshots of their analysis [sarcasm: based on results from their 27 million testers?]:

It seems to me they have adopted the “Cinderella Principle” – push hard to fit the data into a desired result. Are they really claiming that 99% of all Matches at the 6cM level are a 4C or closer? The Ancestry folks are much smarter than that…  They know better, and, for some reason, AncestryDNA is distorting the truth! SHAME! Our tens of thousands of small cM Matches do not fit into a size 4C Cinderella slipper!!

Bottom lines: still rely on 1C or closer relationships for analysis with ProTools; IMO, beyond 2C, treat the estimates as garbage; let me/us know if you have some insight that I’m missing (other than something related to greed).

[22DD] Segment-ology: ProTools 22 – A Rant About Relationships by Jim Bartlett 20250119

Adding a GUESS

Setup

gk (Match1) is known 5C1R – with grandmother: Anetta b 1926 m SURNAME1 > father: private Male > gk; AND gk has 10 known 2C to Anetta’s father (in the line going back to our MRCA).

Justin (Match2) shares 898cM (estimated 1C) to gk; and has a very small Tree of Private Ancestors.

Analysis

To be a 1C to gk, Justin would need to share grandparents with gk – either gk’s paternal grandparents or gk’s maternal grandparents. From the setup (above), we know the maternal grandparents are SURNAME1 and Anetta b 1926; we don’t know (but can often find) gk’s paternal grandparents. In this case there wasn’t enough info in Justin’s Tree to help.

However, there is another way to determine which set of grandparents Justin descends from. If he descends from Anetta’s side, Justin would also be 2C to the 10 known 2C that gk has (NB: all 2C match each other). If Justin descends from the other grandparents of gk, it is highly likely that Justin will NOT share any of the 10 known 2C to gk.  A quick look at Justin’s Shared Match list, shows he matches ALL of the same 2C that gk has. Justin is clearly a 1C to gk on gk’s maternal side – which is the side back to the MRCA with me!

Therefore, I am very confident in adding Justin to my Tree with UNKOWN parent and KNOWN grandparents: SURNAME1 and Anetta b 1926. The rest of the path gk has back to our MRCA is already in my Tree.

This places another Match into my Common Ancestor spreadsheet and into my Tree. It takes this Match off the list of unknown (aka Mystery) Matches. In Shared Match lists, Justin will now show up as a known (Dotted) Match – reinforcing Clusters. I don’t know if Justin’s addition to my Tree will help AncestryDNA with future ThruLines evaluations, but I hope so. I *know* it will help me.

A similar analysis can be made for a Pro Tools estimate of 1C1R or a 2C, but it gets less reliable with each additional degree of separation. There is also a higher degree of difficulty in the analysis, because the certainty of the cousinship estimate is not as assured and the number of possible alternatives that need to be addressed increases. It’s often not impossible, but it is harder. A strong factor is whether a *candidate* Match shares a lot of the same Shared Matches. In other words, if the candidate Match clusters with a lot of the same Shared Matches (which can be observed in the Shared Match list), to me that is a strong indication that candidate Match has the same MRCA. This needs to be tempered with endogamy or pedigree collapse – judgment is needed in those cases.

[22DC] Segment-ology: Pro Tools Part 21 – Adding a GUESS by Jim Bartlett 20250109

A Plan and some TIPS (corrected)

At the end of 2024, I wanted to review my Plan for using Pro Tools (and filing in a Common Ancestor Spreadsheet) and highlight some TIPS .

For the long haul – addressing all of your genealogy using Pro Tools – make a Plan! Perhaps a New Year’s Resolution…

I now think the best plan is to start with the closest Ancestors and work back a generation at a time.

That is, start with your grandparents –two grandparent couples [Ahnentafels 4 and 6]. The Matches at this level would nominally be 1C to you – maybe some “removed” – like a 1C1R or 1C2R – particularly as we get older:>( There are only two groups at this generation – one on the paternal side and one on the maternal side. So, two CA-Couple headers in the CA Spreadsheet. For each row under a header row, enter the Match information (name, cM, # segments, cousinship) and then the child of the CA and their birth year, and then the path to the Match.

TIP1: for each, and every, Match I list, I use Pro Tools to show *their* closest Matches – these are often close Shared Matches to them that can be figured out even if the SM has no Tree.

TIP2: for each Match I list, I add them (and their path to the CA) into my Tree (and apply the DNA-connection and/or DNA-Match Tags). I don’t know if the Tags help AncestryDNA build Trees or determine ThruLines; but it does help me when I run across them days/weeks/months/years later. Not necessarily a *certification*, but at least a reminder that I’ve reviewed the path before.

TIP3: Fill in some Notes for the Match – I always start with my CA code – example: #A0064P [the A means I’m satisfied the Ancestor is correct; and the # is a holdover from the days we searched for unique strings; the 0064P is Ahentafel 64 on my Paternal side [in a DNAGedcom Client Spreadsheet Report, I can sort on the Notes column, and they will group in order]

TIP4: I Star & MRCA Dot & Tagged-in-my-Spreadsheet Dot each Match – this unique Star-Dot-Dot “trio” clearly highlights Shared Matches who are already in my CA Spreadsheet. In a Shared Match list they help identify a Cluster.

TIP5: Each of the Matches under an MRCA Couple at this generation should match each other. They are 1C, 1C1R, 1C2R to you and each other, and all should Match. A Quality Control Check. [NB: I am tempted to add in any Aunt or Uncle Matches to my Spreadsheet; but they may be close to the Match, but not on the path to my Ancestor – when that happens they won’t have close cM ties to the other Matches.]

TIP5: I have a separate column in my CA Spreadsheet to indicate I’ve done all of the above. I’ve got about 8,000 Match rows in my spreadsheet and I’m reviewing each one to make sure I’ve covered all of the above and then check it off. As it turns out, some have changed their Trees, some have dropped out of Ancestry, Ancestry continues to update ThruLines, etc., etc. This checkoff indicates a fresh update.

Time now to tackle the four Great grandparent couples [Ahentafels 8, 10, 12, & 14].

Repeat the steps above for each of your Ancestor couples.

Note that TIP5 still applies – under each couple the Matches are 2C (or 2C1R, 2C2R, or maybe 1C1R) with you. These nominal 2C should all be close cousins to each other (sharing large amounts of cMs)

At any point in this process, take a break and chase down a rabbit hole or two. But then come back to this methodical process.

TIP6: Using this process, makes us treat all of our Ancestors equally. I tend toward favorite Ancestor lines, and this process forces me to grind through all of the Ancestors and Matches.  It’s a good thing.

A slight change occurs at the next generation [eight 2xG grandparent couples; 3C level; A 16 – A 30] At this level, TIP5 breaks down a little.

TIP7: Reminder – 2C-100%; 3C-90%; 4C-50%; 5C-15%; 6C-5% – (roughly)… This is the “curve” indicating how often true cousins will be a DNA Match to each other. ALL true 2C will be a DNA Match to each other. Of 10 true 3C, each one will usually have a DNA match with only about 9 of the others; but each of the 10 will have about 9 of the others matching – so these 10 would still form a pretty strong Cluster… Among a group of 4C, each one will only match about half of the total; and they may not all form one, strong/compact Cluster. And it gets worse, at the 5C and 6C levels… – some interconnecting cousin Matches, but not strong Clusters. However, now with Pro Tools we can find groups of strongly interconnected (closely related) Matches – strong ties to each other, but perhaps their strong subgroup is 5C to 8C with you.

At the 4C level, I see interconnected groups around the children of each grandparent couple; and sometimes a few interconnections between children. At the 5C level, as expected, I’m seeing groups (Clusters) form on the grandchildren.

Additonal TIPS

TIP8: multiple marriages; non-marriages: IF you and a Match only share DNA through one Ancestor, then your relationship is “Half”. Pro Tools often includes cMs for Half relationships, but these only apply with when you share only one Common Ancestor.

TIP9: Some Matches may be related to you multiple ways – give them a separate row (and Ahnentafel #) for each relationship. NB: If you are 3C on A16 and on A18 the odds are equal – with one segment, it could be either; with multiple segments, it could be both… However, if you are 3C on A16 and 4C on A38, with one segment, the odds are 4 to 1 that the DNA came from A16; and if you are 3C on A16 and 5C on A76, the odds are 16 to 1 that the DNA came from A16. This is because *shared DNA* is divided by 4 with each generation, on average. If you have shared DNA with a Match, it’s much more likely to be from the closest relationship.  

Please post in the comments if you have good TIPs that would help us all.

Happy New Year!

[I fixed the error in Tip 7, and reposted]

[22DB] Segment-ology: Pro Tools Part 20a – A Plan and some TIPS by Jim Bartlett 20250101

Comments on Sacrilegious Genetic Genealogy

I thought these comments were excellent and wanted to share them.

Guest Post from Terry Butcher dated 11 Dec 2024

In regards to your Pro Tools Part 16 Sacrilegious Genetic Genealogy post, I would like to share some thoughts on the topic.

While I appreciate the power that various DNA analysis techniques offer in identifying clusters of matches to specific common ancestors, my primary focus has always been about the genealogy side of the effort.

I feel that I need to connect my tree to each match to really have anything of value. I already accept that I am related to my matches (within the parameters you have described related to cM size). Being able to document the relationship and share it with my matches is my reward for investing the time and effort in researching them.

I try to make a connection with each match and approach each one as an opportunity to learn something new. Each match that I find a common ancestor for in essence validates that specific branch of my tree by having both a paper trail and a DNA match.

I add my matches tree into my tree as I research them. I start by adding them as an unrelated person in my tree and start working back along their tree picking up all of their branches until I either find a common ancestor, hit a dead end or believe there is no longer any possibility because of location has gone back to Europe. It usually doesn’t take long to find most CAs. While researching a match, I usually only add parents and the child, ignoring the other siblings to save effort. However, if I am successful in finding our CA, I will usually go back and pick up the other siblings for several of the most recent generations.

I have been systematically working my way through my matches starting with closest related and have made it down to the 41 cM matches (about 2,000 so far).  If the match has useful information in their tree, I have been successful about 90-95% of the time. In the past, I would contact matches without trees and offer assistance. Now with Shared Matches Pro I am able to find their close matches with trees and sometimes find a CA. This is much welcomed capability that changes what is possible in my research.  I have a total of 132k matches now with 11,500 marked as 4^th cousin or closer.  It would take me many, many years to even get through the 4^th cousins and closer matches so I am not worried about running out of matches to research that I have an excellent chance of finding a CA.

For the 5-10% of my matches that I build their tree but can not find a CA, I suspect they may be either connected with 2 brick walls that I have at 3rd GGF or some unknown adoption or incorrect parent in my tree. Several of these unsolved CA matches now tie together in their trees and I am hopeful they will eventually result in solutions.

By working through my matches and incorporating their trees into my tree, I have expanded my tree significantly to over 222k people now.  As nearly all of my ancestors have lived in WV since the early 1800’s, my tree is heavily weighted with WV families. I typically don’t have to add but a generation or two until I find my CA.

I am not concerned about having floating tree branches as I believe they will eventually connect into my overall tree.  Anytime I encounter a common surname in my research, I chase it back until it connects with other members of that family which strengthens the connections in my tree.

I value the ability to generate family tree reports showing the relationship path between my match and myself and always share the typically one-page report with my match by saving it to my Dropbox folder and sharing a link in the message I send them.

Any match that I can connect to my tree to a CA has over 10k ancestors (and their descendants) with many up to 40k.   

My approach over my 30 years of genealogy as a hobby has evolved as it has for most I suspect.  As I research, I pick up as much information as I can including photos, obituaries and sometimes other records like draft registration documents, marriage and death certificates. All of these documents are incorporated into the detailed reports I generate whenever the person is included in the report which makes for some very interesting reading for my matches when I share reports with them. I find that Ancestry provides 98% of my information with a bit of help from the other sites whenever I hit a dead end in Ancestry.

[22DA] Segment-ology: Pro Tools Part 19 – Comments on Sacrilegious Genetic Genealogy by Terry Butcher 20241211

Family Group Sheets

One of the key features of my Common Ancestor Spreadsheet (see post here) is that it offers an arrangement like a traditional genealogy Family Group Sheet (FGS). The FGS has an Ancestor couple at the top of the sheet, with a list of their children down the page with birth, death, marriage dates and places. If we are going to create an inventory of our DNA Matches with known links to an MRCA, this FGS spreadsheet format would be a great way to do that. It also turns out to be a handy tool when working with Pro Tools.

The Common Ancestor spreadsheet for Match cousins is actually a “nested” FGS. By sorting on Ancestor Ahnentafel Numbers, all the Matches connected to one Ancestor are grouped together. By also sorting on the birth year of the Ancestor’s children, this “FGS sort” results with Matches grouped under each child. By adding sorts on birth years for grandchildren and great grandchildren, we get a “nested” FGS. I regularly use my entire spreadsheet sorted by these four columns.

This arrangement has several advantages when using Pro Tools…

1. When Pro Tools indicates a parent/child or sibling relationship to an existing Match (already entered into the spreadsheet), I can create a new row and copy most of the info and just adjust one column – a real time saver. And this works even with new Matches with No Tree, Private Tree, Unlinked Tree, Scrawny Tree, even small cMs – Pro Tools has already provided all the relationship information needed.

2. When Pro Tools indicates a (full) 1C relationship to an existing Match, this limits the relationship possibilities to only two. [In my experience, 1C estimates are highly accurate.] Analysis: the new Match is connected to the existing Match (already in the spreadsheet) on (1) the same side I am on, or (2) on the other side. Be aware of this! If the new Match is on the “other” side, they are NOT part of this Ancestor (Ahnentafel) line. If the new Match has any info in a Tree, this “side” issue can usually be figured out and the spreadsheet cells filled out (mostly by copying from the existing Match). If there is no Tree info, the “side” can usually be determined by looking at the Shared Matches of the new Match (sorted on new Match’s cMs). There should be a clear consensus (at/near the top of that list) of the same Ancestor line as the existing Match.  If not, then skip this new Match. If so, I add a row for the new Match, copy data from the existing Match, and enter GUESS for the new Match parent (as a sibling of the existing Match parent), and then the new Match [NB: to save typing, I indicate each “terminal” Match as an asterisk (*) because they are already spelled out in the Match column near the beginning of the row.]

Analysis summary: A) look at their Tree; and/or B) look at their closest SMOMs.

3. For a 1C1R or 1C2R the estimates are still very good, and the process above can be used. Use available info or judgement to shift the new Match to the right or left per the “removes”. Where the individuals are not known, just put Unknown or Private in the cell. The complete path down to the Match is not critical, IMO.

4. When Pro Tools indicate Aunt/Uncle or Niece/Nephew, that too is highly accurate, as are the genders. Similar to the above, there is usually enough information to place them in the spreadsheet (which is like a horizontal Tree).

5. Pro Tools often includes a Half relationship in their estimate. This is based on tables that indicate two estimates shown are almost exactly the same cM range. Although technically correct, it is much more likely, IMO, that the relationships are standard (NOT Half). But a few will be Half so watch for that situation. Remember these Pro Tools cMs are between your Match and the Shared Match (not affected by whether or not you have a Half relationships with the Ancestor)

6. Adding a hitherto unknown child branch – best described by a recent example I had. In looking for my A38 (ALLEN ancestor) cousins, I found a bunch descending from four well documented children of A38 – 56 Match cousins (4C, 4C1R, 4C2R and 4C3R) with an average of 18cM. There appears to be more than four children in the 1810-30 Virginia census records. And there was an old story about this family, that a son named William went west. So when some known Matches had some SMOMs with ancestor William H ALLEN born 1815 in VA and living in IL, I took notice – it seemed to fit. As I pushed it with Pro Tools I found (so far) 10 Matches descending from William H ALLEN averaging 20cM. But more importantly, those Matches also had Shared Matches with 12 of the 56 Matches from other children from this A38. It sure looked like a Cluster with gray cells to other Clusters! I’d really like to determine William’s Y-DNA; and/or some DNA segment data… But, in the meantime, I’ve got two of William’s descendants checking their Matches for links to my A38 ALLEN. There are 147 Trees at Ancestry for William H ALLEN – not a one has any good clue to his ancestry, except that he was born in VA. Not my Brick Wall, but I think there will be 147 happy campers.

A key point in this long story, is the DNA has no sense of geography. The facts that four children stayed in VA (and were well known) and one child moved far away, made no difference to the DNA. From each descendant’s viewpoint, all the lines were equal – and a pretty even distribution of Matches showed up for all 5 children. The DNA is like blind justice.

7. Equality – a final thought is that this spreadsheet is a lot like the DNA – it’s relatively equal over all the Ancestors and descendants. This spreadsheet encourages me to treat all of my Ancestors equally (they each have an Ahnentafel placeholder row). I still have my “favorite” Ancestors, but as I methodically go through the spreadsheet, I’m spending time on each one. This includes the Ancestors that have issues… This spreadsheet also highlights the Brick Wall holes, to be plugged with floating family branches. This is a good thing.

To me, the key points in doing this spreadsheet work also include:

1. An inventory of Matches who have MRCAs with me. Separate from my on-line Tree. Saved in the cloud and/or archived – available to my heirs or selected genealogy archives someday.

2. Family Group Sheets – of sorts* – this is a standard genealogy tool.

3. A Quality Control check on the accuracy of name spelling and birth years; and the FGS itself. This QC review often reveals “quirks” (as a kinder word) that folks have in their Trees…

4. With Ancestor second marriages, this FGS listing will show the demarcation between full cousins and Half cousins. [I add “INSIGHT” rows with marriage years that will sort and separate the children to the different parent couples.] Half cousins for me only occur at the children level in my spreadsheet. Half cousins between Matches and Shared Matches can occur anywhere.

5. A re-sort by Match name highlights multiple relationships. Since shared DNA is divided by 4 (on average) going back each generation, the closer relationships are much more likely. I’ve found some Matches with MRCAs on both sides of my Tree. With single shared segments, the DNA can only come from one Ancestor. With multiple shared segments, there may be a segment for each line.

* I used “of sorts” in 2 above, because this FGS will not usually be a complete list of all Ancestor children, grandchildren, etc. It includes only the ones who provided a DNA path down to our Matches. Which in turn depends on family sizes and who did DNA tests – there can be wide variations on both.

Note: If I were starting over, I’d probably add name & birth year columns for 9 generations – out to 8C level; and then a catch-all column for any additional info. This would provide a handy way to evaluate the cousinship levels. Reminder: I only list the given name and one initial for males; and the given name, initial and married surname for females. I try to keep it as easy and simple as possible.

Bottom line: An FGS spreadsheet offers an easy way to add new Matches which have been identified by Pro Tools as closely related to known Matches. This adds independent, genealogy triangulation and tight Clusters to an inventory of known Matches. It will be an outstanding adjunct to an auto-Clustering program.

Also – you don’t have to use a spreadsheet to benefit from most of the concepts imbedded above.

[22CZ] Segment-ology: Pro Tools Part 18 – Family Group Sheets by Jim Bartlett 20241209