On mother’s day it seems most appropriate to celebrate my mother’s maternal line; that is all the female ancestors who passed down their H11a mitochondrial DNA (mtDNA)* to me and my cousins. As far as I know it, there was only one woman born in each generation until my grandmother, who had three girls. Each of her daughters had exactly one girl, but only one of us three had any more girls. Fortunately for the continuation of our mtDNA line, my cousin’s two daughters each have a little girl of their own now.
The furthest back maternal line ancestress that I have found is my great-great-great-grandmother Veronika Ebner (nee Engl) of Winklarn, Bavaria, born sometime around 1800. She had my great-great-grandmother Karolina Wittmann (nee Ebner) born 1831 in Eslarn, Bavaria.
Next we get to the women that I know something about and have pictures of.
Retta Reiner, Fanny Thannhauser, Thannhauser daughters
My great-grandmother Margarette Katherina Reiner (born Wittmann) is on the far left on her wedding day the 3rd of February, 1889. In the middle is my grandmother, Franziska Thannhauser (born Reiner) in her youth and on the far right her three daughters as children.
My favorite blogger, Roberta Estes of DNA explained, did a post celebrating her maternal DNA which inspired this post. Thank you Roberta.
“My half-sister and I have been tested to confirm half-siblings. Is there any way to know which parent we share” – this is a rephrasing of a question posed by a woman on the DNA-ADOPTION mailing list at Yahoo. A discussion of the problems of mtDNA ensued. Because the mtDNA haplogroups go back thousands of years, a match is no guarantee of a recent ancestor like a mother. So that information can only rule out the maternal side if there is a mismatch. Deeper mtDNA can get closer but still this is not certain territory yet.
However since they are both female, the X chromosome can give a definitive answer because their father(s) would pass his only X chromosome unchanged to each of them. A man has one X and one Y chromosome and a woman has two X chromosomes. Whether the father passes an X or a Y to his child determines its sex, but since neither is recombined the child gets exactly the same X or Y chromosome as the dad has.
Since a girl has two X chromosomes, one is from her dad. Two sisters with the same dad will therefore ALWAYS match on the entire X chromosome since they have one complete X in common. If the mothers are related, then some of their X will be a full match as well. So let’s look at some X chromosome comparisons at GEDmatch:
This is what the two half sisters from the question look like. The blue indicates that there is a match, the colors above it whether on one chromosome (yellow) or both (green), while red is no match. A few small errors can creep in when processing DNA so an occasional little red line can be from an error. Click the read more once you have decided if they have the same mother or the same father.