How you map your segments is your choice. Some people like to use the name of ancestral couple, while others prefer to use a single ancestor. To take the simplest example:
- If you have a paternal first cousin, you common ancestors are your grandparents on that side, so the ancestral couple would be your father's parents.
- Since you have no way of knowing which grandparent they came from, so the furthest back single ancestor you can assign them to is your father.
Since you inherited one of each chromosome pair from your father, this doesn't tell you much!
But as soon as you can identify more distant matches, your chromosome map becomes more interesting.
For example, if you share four segments with a match who is your third cousin, these segments are from your 2nd-great-grandparents.
You can now 'paint' these segments onto your chromosomes. Since you don't know which of your 2nd-great-grandparents these segments came from, the furthest back single ancestor you can assign them to is your great-grandmother (your mother's paternal grandmother).
When you paste the data in, DNA Painter will automatically paint each segment over the correct part of each chromosome. You can choose your own colours!
You can also use DNA Painter to paint unknown matches and make notes on your matches.
The more matches you're able to paint, the more clues you'll have when new matches come in.
Next: Other chromosome mapping features