Previously, I was working on Chromosome 6, but it was too much of a headache, so I’m skipping that chromosome for a while and starting with a fresh Chromosome: 7. I do have partial sibling results based on the raw data for Chromosome 6, but that seems like cheating.
Adding Crossovers
Some people call these by a different name. They are the vertical lines that need to be assigned to a sibling to show where they have a change in their inherited DNA.
I try not to spend too much time on these initially as they may change.
Lentz Cousin Carolyn
Carolyn is a maternal cousin match on my Lentz side:
By Carolyn’s matches, it looks like I have Jim’s (V) crossover right, but that my Joel (D) crossover should be a Jon (F) crossover. As I look back, I see I made a mistake:
Based on the matches with Carolyn, I came up with this maternal configuration at the start of Chromosome 7:
My Frazer Cousin Susan
Susan shows I was on the right track with Lori’s crossover here:
Here is how I map the matches with Susan:
I don’t want to imply too much with Sharon yet as she has a crossover in this area.
Hartley Cousin Maury
Maury will help map Hartley onto the middle of the Chromosome for 5 siblings:
Hartley Cousin James
Here James’ match with Jim (V) stops at 147.3. I need to add a crossover for Jim (V) there. I’m going to change the L I had there to a V. The start of the match for Joel appears to affirm the crossover I had there.
I also added another D crossover about 1/3 of the way from the beginning of the Chromosome.
Rathfelder Cousin Catherine
This tells me Jim (V) needs another crossover:
Jim’s match with Catherine ends at 72.7M and the others end at 75M. Also my match with Catherine is off of the other matches and probably indicates a maternal crossover for me:
Cousin Beth to Fill in More Hartley
The first L Crossover will be paternal going from Hartley to Frazer. Sharon will also have a Hartley to Frazer crossover at the corresponding S above (123,5M).
The Segment Map
Before things get too far out of hand, it is a good idea to check the Segment Map:
This shows that I am on track as far as I have gone. At this point, I would like to fill in the missing segments using the Gedmatch comparisons:
In the F-V Segment, Sharon and Heidi have an FIR, so I filled in Rathfelder for Heidi there. However, Heidi needs another crossover to go from Rathfelder to Lentz going from right to left.
That crossover is at 36.5M:
Heidi’s crossover looks to be between D and V. Here I did some extending:
However, I ran into a problem with Lori as it looks like she has a double crossover, but I don’t think she should.
More Segment Map Checking
Here, I’ve circled a few problem areas. At least they are only in one section of the Map.
Here is one problem:
Heidi and Lori have a FIR in green. Going from that FIR to the left is an HIR. In order for that to happen, either H or L should have a crossover and there is no H or L crossover there. I think the D crossover above should be an L.
This looks better. However, now I see another problem I didn’t see before:
This is an area that has Jim in common (V). I see that a V crossover is needed for Jim around here:
When I add this crossover, the Chromosome is solved. At least the right hand side:
The Gedmatch comparisons and the Segment Map match each other:
Here is the completed Chromosome:
I was unable to use the Merge function as I added some columns to the left. This shows that I (Joel) have the Frazer DNA near the middle of the Chromosome and the other five siblings do not. Lori carries Lentz DNA in some places where the other five siblings carry Rathfelder DNA. There is coverage of all four grandparents in each section of the Chromosome.
Summary and Conclusions
- I moved on to Chromosome 7 after having trouble with Chromosome 6
- I was able to find missing or mis-attributed crossovers by comparing the Segment Map to the Gedmatch sibling comparisons.
- I am fortunate to have many Hartley side relatives who have tested. This made the work go more easily,
- I am still keeping a list of crossovers with their positions. I am highlighting the rock solid crossovers as the landmark ones that I am really sure of. This helps get the positions right when there are many close crossovers.