One of the Canadian Line of Frazers descends from my 2nd great-grandfather’s brother. His name was Richard Frazer born 1830 in Roscommon County, Ireland:
My 2nd great-grandfather was George William Frazer, born about 1838. Here are the two lines as shown with their descendants that have taken a DNA test:
Visual Phasing is comparing the DNA results of three siblings (or more) and figuring out from which of their four grandparents they got their DNA from on each of their chromosomes. I did that with myself and my four tested siblings. Now on the yellow line we have Susan, Doreen and Ken who have all had their DNA tested. I am 4th cousins to Susan, Doreen and Ken. However, by figuring out where we got our DNA from, it will be almost like comparing our grandparents to each other. Richard Price “Pat” Frazer will be compared with my grandmother, Marion Margaret Hartley. These grandparents would have been second cousins to each other. Now we didn’t get all our grandparents’ DNA, but what we did get, we will be able to identify and compare.
Steven Fox’s Excel Spreadsheet for Visual Phasing.
If you do a Google search for Steven Fox and Visual Phasing, you will find a lot of information and blogs of other’s that have used his spreadsheet. It is possible to do Visual Phasing without his spreadsheet, but his spreadsheet makes it easier, more organized and more standardized.
Jumping in with Chromosome 22
Chromosome 22 is the shortest, so some people start with that one. There should be fewer crossovers on this Chromosome. The downside is that there are also usually fewer cousin matches on this short Chromosome.
This image is small but if you click on it, it should get larger. The top bar compares Ken (K) and Susan (S). The vertical lines represent crossovers where DNA received changes from one grandparent to another. The location of these changes or crossovers are important. It is also important to know to which sibling these crossovers get assigned to. The first crossover is found where the match between Ken and Susan goes from HIR or FIR. HIR is Half Identical Region. That means that Ken and Susan both got the DNA from one of their 4 grandparents at that segment. The problem is, we don’t know which grandparent. After the crossover, represented by the first vertical line, Ken and Susan have an FIR. This is a Fully Identical Region. That means that Ken and Susan both got their DNA in that segment from two of the same grandparents. One matching grandparent was on the maternal side and one was on the paternal side.
Finding the Location for the First Crossover
The second crossover is easy to find, because it is at the same place where Susan and Doreen go from no match to a match. This spot is recorded by Gedmatch at 23,564,890. I could call that 24M or 23.6 depending on how exact I want to be. In the case above, I called it 23.6. To get the first crossover, we have to look at the comparison between Ken and Susan at full resolution at Gedmatch.
Here is the first part of Ken and Susan’s comparison at Chromosome 22:
This says that the beginning of Chromosome 22 doesn’t even start until position 14.5M where M is million. Every little ^ is one million. So counting back from 20M, Ken and Susan go from HIR to FIR between 15 and 16M. I’ll call it 15.7M. The pink part is a centromere. Usually this would be at the center of the chromosome, but there must be information at the very start of Chromosome 22 that isn’t used.
One Crossover or Two on the Right Side of Chr22?
Here is a blowup of the last two crossovers. On the top bar, there is a spot where Ken and Susan go from HIR to FIR. However, this does not line up with position 45.4M where Ken and Doreen go from no match to an FIR. However, to be sure, I need to know where Ken and Susan go from an HIR to an FIR.
According to Gedmatch, the end of Ken and Susan’s match is at 49.5M. That means the last ^ is 49M. That means that Ken and Susan’s change from HIR to FIR is between 45 and 46. I’ll say 45.7. This is pretty close to 45.4, so a judgement call. I’ll just leave it as I had it.
Assigning the Crossovers
The crossover usually gets assigned to the person that is in two of the changes. This is easier to see in the second crossover. There is a change in the top and bottom comparisons. The first comparison is Ken and Susan. The last comparison is between Susan and Doreen. Susan is the common denominator, so she gets the crossover.
I gave the first crossover to Ken:
I had forgotten why. Now I remember. I think that there is actually a very small match that doesn’t show up between Ken and Doreen at the beginning of the Chromosome. It is very subtle, but I’d say that there is more green in the beginning of the K&D comparison compared to the S&D comparison. These crossover assignments can be a bit of an art. If I had lowered the match resolution it should have shown up as a blue match there.
The last two crossovers were not easy either:
These changes have to come in pairs. That means that I had to treat the little segment between D and S as an FIR on the bottom comparison. That means that there are two changes for Doreen first making that her crossover. Then there are two changes for Susan (top and bottom comparisons).
Working on the Segments
This image is the end result, but I will say how I got there. First I started with K&S. They have a FIR for the second segment. This shows as dark green. In the image above, that means that Ken and Susan have two of the same colors. They match with one maternal grandparent and one paternal grandparent. Because Ken has no crossover to the right of the second segment, I can extend that DNA all the way to the right end of the Chromosome on both Ken’s maternal and paternal sides. Also in the second segment, Doreen has no matches with Ken or Susan. That means she has the spouse of the other two grandparents in that slot. So instead of orange and purple, she gets blue and green there. She has no crossover to the left and none on the right until near the end of the Chromosome.
At some point I have to deal with a HIR. I did that with Susan after the second segment. Susan has a HIR to Ken and Doreen. I made Susan match Ken’s purple but not his orange. We already knew that Ken and Doreen had no match in the third segment, so Doreen got the opposite colors there.
The last three bars in the image above represent Gladys’ match with Ken, Susan and Doreen. She shows a match with only Ken and not Doreen nor Susan. This has to be in Ken’s orange section as that is the only place along the match with Gladys that one of his segments is different than Doreen’s or Susan’s.
Gladys and Ken only match on the Frazer Line. Gladys has no Gray DNA. That means orange has to be Frazer. The only other paternal side is Gray so blue has to be Gray. I don’t have specific information on Ken, Susan and Doreen’s maternal side, so those are just labeled G3 and G4 for now. Actually, they should be M1 and M2 for maternal grandparents:
Ken and siblings’ father’s name is Stefansson and their mother’s surname is Gudmundsdottir.
How to Use Visual Phasing
Now that we know where Ken, Susan and Doreen got their DNA from on most of their Chromosome 22, what can we do with this information?
Part of the information is educational. Knowing how our DNA recombined by way of our grandparents is interesting. It is a kind of snapshot of what went into our makeup at conception.
Another part has to do with DNA matches. This focus us as to where our matches are. However, there is still one hitch. We still need to know if our matches are on our maternal or paternal side. If we don’t have a parent to compare our matches with, then it is possible to compare matches with known relatives.
Use of Crossovers
The exception to this is if Susan were to have a match that started before her crossover at 23.6 and continued beyond it. For a match that goes through a crossover, it has to be on the other side. So for such a match for Susan, this could not be a Frazer match but must be on her mother’s side.
These visual phasing maps work best when you have downloaded all your matches. Then you will know for every Chromosome which grandparent they will match depending where in the Chromosome your match is. If you have a lot of matches that end at a certain place and then other matches that start up again at that spot, that could be indicative of a crossover.
Separating Real Matches from Far Away or False Matches
Another way to use these results is to tell if a match is real or not. Here is part of mapped Chromosome 22 showing a small match between Doreen and Michael of the Frazer Project:
It shows that Michael only matches Doreen and not Susan nor Ken. Michael’s match is indicated by a blue bar at the bottome right of the image above. However, Doreen has no Frazer DNA in that segment. She only has Gray DNA on her paternal side. So, it may mean that Doreen matches Michael on the Gray line going way back or less likely on the Icelandic Line. But Michael could not be matching on the Frazer Line assuming I have mapped this correctly. As I mentioned, this is a small match of 5.6 cM. Matches under 7 cM have more than a 50% chance of not being real matches.
Comparison with My Visual Phasing
Here is my Chromosome 22. It is mapped along with three of my siblings. I didn’t get around to mapping Lori.
When I compare the two maps, I can see where my siblings have the potential to match with Ken, Doreen and Susan along the Frazer Line. It doesn’t mean we have to match there. For example, my Frazer grandparent DNA also has Clarke and McMaster DNA that Ken, Doreen and Susan don’t have. Likewise, Ken, Susan and Doreen have other DNA in their Frazer line that I would not share.
Extra Chromosome Mapped
While I was at it, I mapped Chromosome 12:
This was a little easier, because more cousins matched on this Chromosome. One interesting thing about this Chromosome is that between about 88 and 104M, there is no Frazer DNA. That means that if any of these siblings have a match in that area, it could not be a Frazer match.
This map had three spots that appeared to go from a no-match to a FIR or from a FIR to a no-match. This is impossible, so there needs to be a HIR transition. That is why there are three places where the crossovers are close.
Summary and Conclusions
- Visual Mapping shows the process of our makeup based on how our grandparents’ DNA combined to form us
- This mapping can be helpful in identifying DNA matches
- Special attention should be made to crossovers. That is where DNA on one side of our Chromosome changed from one grandparent to the other.
- If a match goes through a maternal crossover, for example, it means that match must be on the paternal side.
- A lot of genetic genealogy is about separating out the DNA and visual phasing goes a long way in doing this.
- Other sorting can be done by names or location of matches. As Ken, Doreen and Susan’s mom is Icelandic a clue as to the matches’ names, locations or genealogy can be a hint as far as placing them.
- Visual Phasing works best when there are good cousin matches on all four grandparent sides.