I went a bit out of order as my last Chromosome solved was Chromosome 16. That just shows how easy it is to make a mistake or get mixed up.
Chromosome 15
On the right, on a separate spreadsheet, I write down the initials and the locations of the crossovers. The three locations in yellow indicate that I am not sure of the order of the crossovers. I was also not sure of the last crossover. However, I have convinced myself that there is one there:
I believe that the last segment is a small HIR in the V & D and the V &L comparisons. This last crossover will go to Jim (V).
Next, I go through the crossovers again and write down the position numbers:
This gives me a second look at the crossovers. I think I have this right now. I am missing the last position number which is not a big deal. I can get it from the full resolution comparison between Jim (V) and Jon (F):
The beginning of the match is at 95.5M. Each ^ is 1M, so the beginning of the FIR (and thus the crossover) is as 99.4.
Cousin Matches
This Chromosome should be easy to solve. Here are matches with Hartley cousin Patricia:
My first match ends at 41.4 while Jon and Lori’s matches end at 43.7M. That seems to indicate a crossover that I didn’t see on the paternal side. However, my match with Hartley cousin Beth clears that up:
Beth shows my match goes way beyond 41.4 to 53.9M. Here is how I fill in paternal DNA based on Beth’s match with me and my siblings:
Here I have assumed that a no-vote for Hartley is a vote for Frazer.
Match with maternal Rathfelder cousin Inese may be enough to solve the Chromosome:
Next, I should be able to finish by extending DNA to the crossovers and comparing the sibling pairs from Gedmatch:
However, when I get to the right-hand side, I see that I have done something wrong. The Joel (D) and Lori comparison show an FIR in the next to last segment. However, to do that would require a double crossover for Lori and she only has one. Perhaps the Segment Map will show my mistake:
Here I boxed some areas that are right in the sibling comparison, but wrong in the Segment Map (which represents my Chromosome Map). Interestingly, the first mistake is at V but at the F & D comparison.
The Segment Map pointed out exactly where the problem was. I have a crossover at V which doesn’t make sense. I should only have crossovers at D. I’ll take that V crossover out and carry it over to my next crossover:
After my next crossover, I see I have an FIR with Lori. That means that my crossover has to be on my maternal side (Lentz).
Next I won’t outline all the problems, but I do see one at the top:
This one starts with Jon (F). There should be an FIR, but I have NIR. I can fix this by reversing Jon’s crossover at F. This is confirmed by an FIR between Jon and Heidi:
When I reverse Jon’s crossover, I see that I have corrected the two errors:
Here is what I get for a finished Chromosome 15:
This looks like a match:
Summary and Conclusions
- Two mistakes were solved by comparing the Segment Map to the Gedmatch sibling pair comparisons.
- Joel and Lori have recieved a full dose of Hartley on their paternal sides.
- Sharon has a full dose of Frazer. Jim has 99% Frazer DNA on his paternal side of Chromosome 15.
- A bit of Rathfelder is missing.
- So far, it seems like the paternal Hartley and Frazer are the most popular for full Chromosomes. Maternal Rathfelder is least likely to be represented across the chromosome for some reason. This may have to do with the fact that females tend to have more crossovers than males on average.