Category Archives: siblings

Negative evidence: autosomal DNA

Last time I posted about negative findings and negative evidence, in traditional document-based genealogy and in genetic genealogy. Link here.

Now for the fun stuff – a cool use of negative evidence in *autosomal* DNA. For this exercise, the research question is: from which grandparent did the DNA segment in question originate?

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Chromosome mapping with siblings – part 2

Last month when we left off, we were comparing three siblings’ DNA on chromosome 11, which produced the following ‘map’.  See Image 1. (If you’re just joining us, please see Chromosome mapping with siblings, part 1 first.)

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Chromosome Mapping with siblings – part 1

This month – another post on testing siblings and on using GEDmatch.

Sometimes, having siblings’ DNA tested is a real treat—such as when one of them connects to a distant cousin still residing in Ireland, just a few kilometers from where my ancestors came from. But sometimes—playing with sibling DNA can be a real challenge! Case in point: Chromosome mapping with three siblings. This is advanced stuff, yo.

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How Irish are we?

Rumor has it that AncestryDNA and FamilyTreeDNA are working on updates to their “ethnicity” reporting. Since this is the month many of us celebrate being Irish (AncestryDNA is even offering a $10 discount on DNA kits in honor of St. Patrick’s Day), I thought I’d take a minute or two to muse over this question:

How can two full siblings (as seen in the pie charts above) have such different ethnicity reports?

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