Using the Chromosome Mapper to make a four generation inheritance picture

My friend Angie Bush is a most creative genetic genealogist whose daughter Brynne is apparently following in her footsteps. They do a lovely presentation on autosomal DNA together which includes this slide showing four generations of DNA inheritance, made with my ancestor chromosome mapper.

Three generations of DNA to Brynne

Four generations of DNA to Brynne (click to see a larger version)


Little did I know when Angie asked me for a feature to select the colors herself what a clever thing she had in mind. Each grandparent is shown in two colors, one for each of their parents. Those same colors are carried through on each chart so the names next to the colors on Brynne’s chart are those of her eight great-grandparents. How wonderful to have four generations of family tested.

Here is the close-up of the ancestor chromosome mapper chart for just Brynne:

 Brynne's DNA from her eight great-grandparents

Brynne’s DNA from her eight great-grandparents

Interesting that she has chromosome 21 intact from her paternal great-grandmother Marilyn. Also notice how little recombination occurred on her X chromosome.

This presentation called “Ancestors in DNA” was given near me at the Carlsbad DNA Special Interest Group (DIG) and has been submitted for a number of upcoming conferences. Check back here to learn when they will be giving it. I really look forward to going to this one!

12 thoughts on “Using the Chromosome Mapper to make a four generation inheritance picture

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    • WOW, so you do! And that is much larger chromosome.

      Brynne, Thank you so much for sharing this picture. It is really fascinating to see a real world example of how DNA is inherited.

  1. I’m green with envy at Brynne’s chromosome map — how wonderful to be able to create something likethat. Those who have the opportunity to test their grandparents (or beyond) are extremely fortunate. I count myself very lucky that at my age both parents are still alive and have been tested.

    I love being able to select my own colors on your mapping tools, Kitty, so thanks for adding that capability.

  2. This is wonderful, but it is not clear to me how you are so certain where every bit comes from, even if none of it is endogamous. Surely not all eight great-grandparents were tested.

  3. I’m trying to understand ged match.com. what does it mean when there are numbers/letters on the Mt haplogroup side and the Y haplogroup side? Then some just have numbers/letters on the Y haplotype side.

  4. I have looked at Brynne Gallup’s results and they are fairly typical of the average crossovers reported in the literature. An interesting result of the crossover frequency ratio between paternal meiosis and maternal meiosis being 1.6:1 is that average segment length is larger by 60% for paternal than maternal in each generation.

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