Category: Hartley

In a previous Blog, I mentioned My Big Fat Chromosome 20. I had discovered, for some reason, that more than one half of all my matches were on this Chromosome. This can be seen visually using a Swedish web site called dnagen.net.

Here the default setting is at 200%. That means that only the matches that are twice as large as the median are shown. This program uses FTDNA matches. The match names are on the outside of the circle and the lines going between the names are what FTDNA calls ICW or (In Common With). I just noted today that there is a group on this circle that doesn’t connect with others at about 9 o’clock on the circle. These matches like to stay in their own Chromosome apparently. They are in a dark color which I take to be Chromosome 3. However, that is an aside.

The real point is to show Chromosome 20 in the dark green in the lower right half of the circle. Chromosome 20 is the Hong Kong of Chromosomes. In a little space, I have  lot of matches. Remember that Chromosome 20 is one of the smaller Chromosomes. If I have about 4,000 matches, that means that over 2,000 of them are on Chromosome 20. In my previous Blog on Chromosome 20, I determined that these matches were on my Frazer grandmother’s side. Her 2 parents were born in Ireland. That means that these matches represented Irish matches and not Colonial American matches as I had previously assumed.

The Progression of Sorting Matches

Autosomal DNA matches may be grouped in different ways. When I first tested, I got a bunch of matches at FTDNA. I didn’t know who any of them were. FTDNA had suggested some relationships which were mostly optimistic. Here is some of the progression of how I have sorted my matches:

1. Sorted by projected relationship or match level (cMs)
2. Sorted by actual relationship if known
3. Sorted by Chromosome. This option is not available at AncestryDNA. One has to upload the AncestryDNA results to gedmatch for this option. This is when I discovered all my Chromosome 20 matches.
4. Sorted by Triangulation Groups. By using a Tier 1 option at Gedmatch or by finding by hand all the matches that match each other at a particular segment, I was able to find many Triangulation Groups (TGs)
5. Sorted by Maternal or Paternal. All our valid DNA matches should match on either the maternal or paternal side. Once I tested my mother, I was able to phase my results at gedmatch and find out whether I matched other testers on my mother’s side or my father’s side. This was a big breakthrough for me. This cut down a lot of frustrating searches. For example, there are a lot of people that match my mother that have Frazer or Fraser ancestors. My Frazer ancestors are on my father’s side. Therefor, I knew that when looking for Frazers, I could eliminate all my mother’s matches who had them as ancestors and not worry about them.
6. Sorted by other known matches. I had my father’s 1st cousin tested. This got to the level of my great grandparents on my Hartley side. However, it didn’t tell me which great grandparent. My Hartley great grandparent was a relatively recent immigrant from England. My non-Hartley great grandparent had ancestors going back tot he Pilgrims in Massachusetts. I also had other relatives tested and found other matches that I knew I was related to.
7. Another breakthrough happened after I had my 2 sisters tested. I used a method by Kathy Johnston to find out where you got all your DNA from your 4 grandparents by comparing your DNA results to 2 siblings. This method worked pretty well on most of my chromosomes. Now I knew where the DNA was coming from at my grandparent level for most of my matches. When I had a match, I could check my map to see which grandparent that match belonged to.

That is about where I left it at my last Blog on Chromosome 20. I looked at my crossover points for Chromosome 20. Here are my sisters compared to each other and to me:

Here is how I used the above comparison to map my grandparents that gave me my Chromosome 20 segments. The blank parts are half identical and ambiguous, so rather than guessing, I left them blank. For example, on Sharon’s row on the top, either the orange goes to the left and blue starts at the lower half or the opposite: the purple continues to the left and the green starts at the crossover line.

My chromosome 20 is on the bottom. At the time I wrote my previous Blog on Chromosome 20, I discovered that the vast majority of my matches were due to my Frazer side (green) and not my Hartley side (orange). This was a surprise as my Hartley grandfather had a mother with American Colonial roots. The final point of my previous blog on the subject was:

The fact that all these matches are on my Frazer line doesn’t necessarily mean that they are Frazer matches. They could be McMaster, Clarke, Spratt or any other known or unknown ancestor of my Frazer grandmother.

It’s great that I now know that most of my Chromsome 20 matches are Paternal and that they are on my Frazer grandmother’s line. But I am still curious as to where they are coming from. Can I find out more? I would like to try.

Chromosome 20: Beyond Grandparents

One advantage I have is that I am working on a Frazer DNA project with 27 testers. There are 2 lines of Frazers. I am on the Archibald Line and there is another line called the James Line. These 2 lines are somewhat distantly related as these 2 brothers were born in the early 1700’s. Here are the matches for the project on Chromosome 20:

All of these matches involve at least one James Line tester which I am not on. The 2 major matches between the Archibald Line and James line are between myself (JH) and my sister (SH) on the Archibald Line and Bonnie (BN) on the James Line. As I show below, even my McMaster Line has Frazers in it, which could be the source of that match. Sharon had very few Chromosome 20 matches compared to her siblings Heidi and myself. The 1,000 plus matches I had were before the 47 million mark where I match Bonnie above. My mega-matches mostly occur on Chromosome at 44,000,000 (End Location) or before. This tells me that my mega-matches are not of the Frazer surname. If they were, I would have seen some of my closer Archibald Line matches on Chromosome 20 from the Frazer DNA Project.

Enter cousin paul

Paul is my second cousin once removed who tested for DNA. His great grandparents are my 2nd great grandparents: George Frazer and Margaret McMaster.

When I compare myself to Paul, I get to either the Frazer or McMaster Lines. This will eliminate the Clarke line of my great grandmother and her Spratt mother as they are not in Paul’s line – only mine.

My McMasters: It’s a Bit Complicated

Here is my McMaster Line going back from my Frazer grandmother.

Not only did 2 McMasters marry each other, one of them had a Frazer mother! Marion Frazer is my grandmother, so she is 2 generations from me. Margaret McMaster is at 4 generations. James and Fanny McMaster are at 5 generations to me. Their parents (the left-most McMasters above) are at 5 generations out from my cousin Paul and six generations from me. This is useful to know in the Generations Estimate I have below.

Here is where the Frazer/McMaster split is.

George Frazer b. 1838 is on the left and Margaret McMaster b. 1846 is on the right. The photo was taken in Ballindoon, Ireland in front of the Frazer family home.

At Gedmatch.com, I compared Paul and myself at:

People who match one
or both of 2 kits Updated

I chose most of those that matched both Paul and me. I left out an apparent duplicate and one who is anonymous for now. I also left out my 2 siblings. With those results, I chose the Traceability option and got this chart:

Those in red are in the Frazer DNA Project. We know their genealogy. Gladys descends from the couple above George Frazer and Margaret McMaster. Michael and Jane descend from one level above that. The circle above are those that are related to Paul and me, but not to others in the Frazer DNA Project. [One exception is Jane, but she matches at generation 7 which is about as far out as Gedmatch goes. This may or may not be a real match.] If those in the circle are not Frazer, then the apparent conclusion is that they are McMaster relatives.

Back to chromosome 20

See all the Chromosome 20 matches on my Gedmatch Traceability Report:

Remember I said that my 1,000 plus matches on Chromosome 20 ended around 44M? This is what the above shows. It also shows a triangulation of matches. This triangulation is also implied by the cluster of matches within the circle of the Generations Estimate Chart above. The Chromosome 20 Triangulation Group (TG) includes:

• Myself
• *S. S.
• Daphine
• Feeney
• Gladys

Now Gladys should not be in this list as she is in the Frazer DNA Project and has no known McMaster ancestors. In fact, when I run the ‘one to one’ at Gedmatch, she doesn’t match the others in the above list. There are glitches in the Traceability Report, so caution is needed. I will take out the last 3 names in the Generations Estimate to simplify the results. Unfortunately, that didn’t fix the problem, so I had to take out Gladys from the Frazer Project (sorry Gladys).

Now my presumed McMaster relatives are in the green circle. Here are the improved and simplified matches:

I note now that the 2 ‘M’ kits (indicating 23andme testers) are now matching each other which is what I had expected previously. Note that I left my previous Traceability results in the blog as a warning that the Traceability utility is glitchy. Actually the new report is not indeed improved as now Michael from the Frazer project is matching my presumed non-Frazer McMasters. I took out Michael, and then Jane from the Frazer Project developed similar bogus matches with those she is not related to!

I’ll have to take out all the other Frazer Project people out for this Traceability to work. This was supposed to have worked so smoothly. Here below Joel and Paul should be the remaining McMaster relatives:

Here is the Chromosome 20 TG. Note that Paul is not in it, but he matches others from the TG in other Chromosomes:

This chart is only mostly right. Paul’s green match is actually on Chromosome 19 rather than 15:

Here is the globe view of my proposed McMaster relative TG:

The colors in the lines correspond to the colors in the chart above. The light blue lines are the Chromosome 20 TG from my “big fat” area. The blue lines indicate a TG as they go from each of six people to the other 5. The gray lines represent multiple matches. I am at the bottom of the globe and my cousin Paul is to my right. He is not in the blue TG on Chromosome 20, but matches all my matches on other chromosomes at least once.

Conclusions and Further Research

From what I have shown above, I feel like I have found my McMaster relatives through DNA. However, these would have to be verified by genealogy. None of my proposed ‘McMasters’ have any gedcoms at gedmatch.

• Daphine – she is on FTDNA but with no tree and no ancestors mentioned. An ICW search reveals 59 pages of matches – likely mostly on Chromosome 20.
• Edge – He is at FTDNA. He has a limited tree. His paternal grandmother may be a lead. He has only 52 pages of in common matches at FTDNA
• John – A search at 23andme showed nothing. Perhaps he is anonymous there.
• Feeney – Same result – or perhaps these people are using different names?
• *S.S – I see an S.S at Ancestry, but it is difficult to tell if it is the same person.

I have McMaster connections through DNA and genealogy at AncestryDNA, but there is no way to tell if the connection is on Chromosome 20 without a chromosome browser. My Mcmaster matches at AncestryDNA either don’t know how to upload their DNA to gedmatch, aren’t interested or haven’t gotten to it.

Opposition to TGs

Of late, on Facebook, there has been questioning as to the validity of  TGs – especially large TGs like I have at Chromosome 20. The thought is that no common ancestors will be found as there are just too many common ancestors in these large TGs. I have not explained the 100’s of matches in my Chromosome 20 TG, but I have shown 5 people that match both myself and my cousin Paul. These 5 by DNA do not have obvious Frazer ancestry and appear to be in my McMaster Line. So I suppose we have a stalemate. I cannot prove at this time (except to myself) that my Chromosome 20 TG matches are McMaster relatives and those who are not in favor of large TGs cannot prove that these matches are not McMaster relatives.

I was thinking of calling this Blog “Kathy Meet Kitty“. Kathy is Kathy Johnston who taught me how to map my ancestral segments by comparing my DNA to two of my siblings’ DNA results and determining our crossover points. The crossover points can then be used to map out which grandparent you got your DNA from without having to physically test those grandparents. This is quite convenient as all my grandparents have been gone for quite a while. Kitty is Kitty Munson who has developed a Chromosome Mapper here. I have not seen a blog using Kitty’s Chromosome Mapper to map ancestral DNA segments via Kathy Johnston’s method, so I thought that I would write one. Kathy’s method is posted here.

Two Types of Segments

There are two types of segments, thus at least two types of segment mapping. This concept is best explained at the Segmentology Blog in an article appropriately called, What is a Segment?

ancestral segments

That Segmentology article first mentions ancestral segments. These are the segments that Kathy Johnston knows how to map. I have written many blogs about mapping my ancestral segments using her method. Ancestral Segments are the segments that you actually get from your ancestors. They fill up all your DNA. Here is an example of the ancestral segments that I have mapped to my four grandparents.

Look at Chromosomes 1, 5, 6 and 7 for starters. This shows all my DNA filled in. The 2 paternal grandparents are on the top half of the chromosomes in blue and grean and the maternal two grandparents are on the bottom in red and peach color. The DNA I received alternates between one grandparent and another and fills in all the area. In fact, that is the process of recombination and can be seen in the Ancestral Segment Maps.

shared segments

These are segments that you find at gedmatch.com for example. These are our DNA matches. These matches may have a proposed relationship based on how much DNA you and your match share. Here is an example of some of my matches using Kitty’s Chromosome Mapper.

The best way to fill in a map like this is by testing as many relatives as possible. Now look at chromosome 1, 5, 6, and 7 on the shared segment map compared to the ancestral segment map above. The ancestral segment map on Chromosome 1, for example,  shows how much DNA I actually got from my Hartley grandfather. The blue in the Shared Segment Map shows how much I matched my father’s cousin. Next look at the maternal (bottom) part of Chromosome 1. Here the Rathfelder and Lentz matches on the right hand side are filled in on the Ancestral Segment Map. However, there is an additional section of Lentz on the left hand side of the Ancestral Segment Map where I don’t even have a match. I can tell I got my DNA there from my Lentz maternal grandmother. That is due to the crossover points I have and the fact that the DNA you get from your grandparents alternates between grandparent. On the maternal side, the alternation is between Rathfelder and Lentz.

If you find any inconsistencies between my Ancestral Segment Map and my Shared Segment Map, that means I messed up somehow.

More Ancestral Segment Mapping: Sister Heidi

In order to map my ancestral segments, I needed two siblings, so I used my two sisters, Heidi and Sharon. Here is Heidi’s ancestral DNA mapped out:

A few observations:

• The areas of pale blue are where I had trouble figuring out how to map the ancestral segments, so nothing is mapped in these areas. I may have mapped out some of the segments, but then had difficulty telling whether they were maternal or paternal due to lack of known cousins that had tested. So I left these areas blank
• The maternal areas shown as MG1 and MG2 – For these areas, I knew I had two maternal grandparents but I wasn’t sure which was which. Again based on lack of known cousins that had tested. I could perhaps guess, based on actual matches I had in these segments or where those matches were from, but I noted where the crossovers were and left these grandparents un-named.
• These unknown grandparents are consistent within each chromosome and each sibling within each chromosome, but they are not consistent between chromosomes. So the unknown MG2 in Chromosome 8 may not be the same MG2 in Chromosome 11.
• In my (Joel’s) Ancestral Segment Map, I don’t show any DNA on my paternal side for the X Chromosome. That is because males don’t get an X Chromosome from their father.
• Heidi shows that she got her paternal X from her dad’s mom – a Frazer. Further, that chromosome did not appear to recombine. That means that she got that whole chunk from one of her great grandparents on the Frazer side.

How Do You Know What You Are Finding If You Don’t Know Where To Look?

These maps are very helpful in showing you where to look for DNA. Many people have matches that have ancestral names that are common to us but are not related. For example, my mother has matches with people that have Fraser or Frazer ancestors. I am related to Frazer on my father’s side. That means that I can forget about following up on maternal Frazer matches.

• If I do want to look for Frazers, I need to look in my green areas (or my sister’s green areas) which is on her paternal side.
• My sister Heidi is in an important Frazer Triangulation Group on her Chromosome 1 on the right hand side. She triangulates with others in a Frazer DNA Project I am working on. I am not in that group. Look at my Chromosome 1. It is nearly all covered by Hartley DNA. That explains why I don’t match these other Frazers at standard thresholds.
• What if we were to want to look for Lentz ancestors of Heidi? We need to look at the red areas. Chromosomes 1, 6, 9. 14, 20, and 22 would be a good place to look. Fortunately, I also have Heidi’s matches on a spreadsheet. They are mostly divided by maternal and paternal matches. My mother has been tested for DNA. Based on that, I have Heidi’s phased maternal and paternal results and her matches to each of those results using Gedmatch.com.

Finally Sharon

My sister Sharon completes the Ancestral Segment Mapping:

• The autosomal DNA that is missing on Sharon’s Map is the same for her 2 siblings. This is because Kathy Johnson’s ancestral segment mapping technique compares the siblings to each other using the Gedmatch.com chromosome browser.
• Sharon has a lot of Frazer DNA match potential at Chromosomes 1, 8-12, 15, and 22.
• However, Sharon is also not in the Frazer Triangulation Group in Chromosome 1 on the right hand side. In that particular section, she got her DNA from her Hartley paternal side.
• The above point shows why it is important to test siblings.
• Heidi and Sharon both have a large match (50+ cM) with someone on their X Chromosome. This person also has autosomal matches with my sisters and others in the Frazer DNA project.

Summary and Observations:

• Ancestral Segment Mapping can be useful in determining which grandparent your matches match.
• I know already whether my matches are on my maternal or paternal side. However, this goes back one more generation and further sorts my matches to grandparents. This cuts down the guessing by another half.
• The maps also point out the areas where you can’t be as sure as to which grandparent your matches match as those areas are not mapped yet.
• Ancestral Segments should line up with Triangulation Groups
• Ancestral Segment Mapping can show matches that are Identical by Chance (IBC) or false matches.

I never would have guessed 10 years ago that I would be blogging about my Chromosome 20. 10 Years ago I was definitely interested in genealogy, but knew virtually nothing about DNA. Even if I did know anything about DNA I would not have guessed that it would have anything to do with genealogy.

My Chromosome 20

My Chromosome 20 actually isn’t that big and fat. Actually it is one of my smallest chromosomes. However, I have more matches there than on any other chromosome. In fact, over 1,000 – more than a quarter of my matches – are on Chromosome 20. This is pretty amazing considering I have 23 chromosomes counting my X Chromosome. If my matches were spread out evenly over these 23 chromosomes, I would expect each chromosome to have about 4% of my matches. This representation shows the ridiculous number of matches I have on Chromosome 20. They are on the bottom of the image in light blue.

This particular representation is for just my FTDNA Family Finder matches. I believe the threshold was set relatively high and this was done a while ago. However, at the time and threshold, it appears that more than half of all my matches were at Chromosome 20.

How To Explain All the Matches? Colonial Massachusetts?

I had a difficult time explaining all the matches I had on Chromosome 20. Most were on my paternal side as that is where most of my matches are. I had guessed that these may have been due to a colonial effect as that had been suggested in various places. My great grandmother’s mother was a Bradford and was descended from the Mayflower Bradfords. A lot of those early Pilgrims married other related Pilgrims. In fact, some of my Chromosome 20 matches were descended from a Brewster who was one of the Pilgrims that I am also descended from. Then there were a few who seemed to be related on my Irish Frazer side. Finally I had a match with Bonnie from the Frazer DNA Project I am working on. She matched on Chromosome 20 but was outside my large triangulation groups.

Chromosome 20 Triangulation Groups

I also have Triangulation Groups (TGs) for Chromosome 20 – very large ones. In fact, gedmatch would overload when I tried to run an analysis I had so many. I have 2 paternal TGs and one maternal TG. There also may be sub-TGs within those.  I have roughly 650 matches in these combined TGs. So now, based on testing my mother, I knew if my matches were maternal or paternal and if they were in TGs, but I still didn’t know much about where the common ancestors could be other than a vague guess about colonial Massachusetts. What I did was ignore Chromosome 20. I gave up even adding matches to my spreadsheet because I had so many. These matches tended to be around 13 cM with some higher and some lower.

Sticky Segments Or Pileup Areas?

While looking for a Chromosome 20 explanation, I read about sticky segments and pileup areas. Sticky segments are those that came down intact for many generations. They don’t want to go away. However, a few sticky segments wouldn’t explain over 1,000 matches. It seemed like I had a pileup, so I looked into those. Pileup areas are areas are described by Jim Bartlett in his comment on one of his blogs:

I do find that each person tends to have two kinds of pileup areas: 1) are fairly narrow, are widespread, and are outlined in this ISOGG article: http://isogg.org/wiki/IBD#Excess_IBD_sharing; and 2) are also fairly compact (7-9cM) and are unique to each person. I believe these are caused by a unique set of markers in our personal DNA that makes it easy to form matches with others in that region. These are characterized by many segments in a narrow range, which do not generally Triangulate, and the Matches don’t see this as a pile-up area, only you do.

However, my case didn’t seem to match some of the explanations of sticky segments or pileup areas. My matches were larger and did triangulate. Furthermore, they were not in areas of the chromosomes described in the ISOGG article above.

Enter Kathy Johnston and Her Crossover/Segment Analysis

At the beginning of 2015, Kathy posted her instructions on an FTDNA Forum for analyzing DNA based on the 3 siblings. She showed how to determine the 4 grandparents’ contributing DNA for each of these siblings.  I discovered her post at the end of 2015. Could this help me figure out my Chromosome 20? I tried Kathy’s method and got some surprising results.

Finding Chromosome 20 Crossover Points

Finding crossover points in Chromosome 20 was not as easy as it has been in other chromosomes. According to Kathy, usually there will be one owner of a crossover point. This owner will appear in 2 out of the 3 comparisons at a crossover point. In this one, I found only one clear owner. That was my sister Heidi at position 47. For the other ambiguous crossover points, I gave a double initial separated by a slash.

Below, the gedmatch comparison is transformed into a maternal/paternal Chromosome 20 map. The green area means that Heidi matches Joel on the 3rd segment. This match is a Fully Identical Region (FIR). This means they match the same maternal grandparent and the same paternal grandparent. For Joel, I move those grandparent to the right as I have no crossovers until the last crossover point.

Sharon has no match with her 2 siblings in the same area, so that will mean she shares the complementary grandparent on her maternal and paternal DNA. This will be represented by 2 different colors. I again extend that double segment to Sharon’s crossover points.

Looking at the earlier gedmatch comparison, in the 2 segments to the right of Heidi’s existing mapped segment, there is a Half Identical Region (HIR). That means a grandparent matches on one chromosome and doesn’t match on the other. This will be shown as 2 different colors in this area when comparing Heidi to Joel. This first HIR choice is chosen randomly as no names or side (maternal/paternal) have yet been assigned to the grandparents.

Next, we have an illogical situation.

In the next to last segment, the smaller one, Sharon is no match with Heidi or Joel and Heidi and Joel have a half match. That is illogical because if Sharon doesn’t match with Joel, that is the same orange/purple scheme continued in the small segment for Sharon. Then if Sharon and Heidi are opposites, it goes back to green/blue for Heidi in that small segment. Those are the same colors that Joel already has, so that means that Heidi and Joel can’t be HIR which means they should have one matching color and one non-matching color. However, look at that small segment again in the first two rows. The red is strong in the first row. In the second row, I hardly see any red – with red indicating no match at gedmatch. Therefor, I’m going with the first comparison of Heidi and Sharon. Plus this goes with the matches that I will mention soon that Sharon has. I make Sharon and Heidi opposite in Sharon’s little segment and extend that segment to the end.

I filled in some of the no matches and FIRs on the right. On the left, I was left with 2 illogical no matches again, so I chose the redder of the 2. This left me with having to guess a HIR on the left. I am only allowed one guess, so I left this blank for now.

Adding Real Grandparents

It would be nice to add actual grandparents here and not just speak of my orange grandparent, for example. I can do this using two of Sharon’s matches.

These 2 important matches Sharon has are both on the paternal side. James is related to my grandfather and Bonnie is in the Frazer DNA Project on my Frazer grandmother’s side. Coincidentally, the orange match above goes with the orange on my chromosome map. That would make my paternal grandfather Hartley orange and paternal grandmother Frazer green.

Joel’s Matches

Here’s my Frazer match with Bonnie. 47 to 54 is in my green Frazer region on my map. So that is a relief.

Below is my only maternal match. It is with a cousin on my maternal grandmother’s line. She matches only with me because she tested at 23andme and hasn’t uploaded to gedmatch yet.

However, Judy gets me unstuck on my maternal side. Her match is telling me that from zero to 8, I can identify my grandparent. I already have blue from 6 to 8 (from using my brighter red logic). So I just need to extend the blue all the way to the left on my maternal segment line. That gives me a solid blue on Chromosome 20 on my maternal side.

This is as far as I can figure out now without further guessing. Perhaps when cousin Judy gets her DNA uploaded to Gedmatch, I will know more. So what does this tell me about my 1,000 plus Chromosome 20 matches and 600 plus matches that appear to be in Triangulation Groups?

Mystery Solved?

I think it is. These matches correspond to the area on the map above between 16 and 49. By the above mapping these massive amount of matches are solidly in Frazer territory for me. Instead of my huge block of matches being in colonial Massachusetts, I see that they are on my Frazer line. That came as quite a surprise. These ancestors were in Ireland mostly. I assume that many of these ancestors got out of Ireland. Perhaps they moved to the United States and married people who were descended from colonial Americans. That would explain some of the other colonial matches.

Summary, Application and Conclusions

• When you are looking for DNA matches, it helps to know where you are looking
• While I was looking at my largest group of matches, I was looking in the wrong place even though I had some reasonable assumptions
• Kathy Johnston’s method cuts through bad assumptions and replaces them with sound logic
• Phasing by parents cuts the looking in half but didn’t help me with identifying a huge block of Chromosome 20 matches. However, Kathy Johnston’s method is twice as good as phasing as it separates all matches to areas of 4 grandparents.
• This method needs 3 siblings and some known tested relatives.
• If I have this mapped correctly, any maternal match after 6 million for Sharon will be on the Rathfelder line and any maternal match for me will be on the Lentz line.
• Interestingly, I have only about 42 matches for my sister Sharon on this Chromosome. Given that the makeup of her Chromosome 20 is mostly opposite of her 2 sibling, this makes a lot of sense.
• I forgot to mention that my sister Heidi has almost as many matches as I do on Chromosome 20. Her shorter Frazer segment compared to mine would explain the slightly fewer matches.
• The fact that all these matches are on my Frazer line doesn’t necessarily mean that they are Frazer matches. They could be McMaster, Clarke, Spratt or any other known or unknown ancestor of my Frazer grandmother.