She Explains: I donated a swab of cheek cells to determine my "mitochondrial DNA haplogroup."  In the project, they are studying the migration patterns of homo sapiens based on mutations of DNA.  Basically, everyone has mitochondria, and it is inherited from the mother only.  Males receive it from their mothers, but can't pass it on to their offspring.  Females pass their mitochondrial DNA to all of their offspring.  This DNA is passed down through generations, unchanged, except for occasional mutations.  In the project they have grouped people according to mutations found in the mitochondrial DNA, and followed the migratory routes of the people in these groups.

So, my mitochondrial DNA is identical to my mother's, which is identical to her mother's (Nell Boerema), which is identical to her mother's (Geertje Roest De Korne).  All of the children of Geertje Roest DeKorne have the same mitochondrial DNA- including Celia De Korne Wierenga, (my mother) and all of the children of Geertje's daughters have the same mitochondrial DNA- including Don Wierenga.

Our "haplogroup" is known as J2.  It arose in the fertile crescent around 50,000 years ago.  It is not very common in Northern Europe, but pretty widespread in the Mediterranean.  I must say I always wondered about the dark eyes and bone structure of the DeKornes- not very Dutch looking.  So the J2 haplogroup can be traced back in this way:  Don Wierenga-> Celia De Korne-> Geertje Roest-> Celia Cornelia Van Wieringen- (See photos I have recently received)> Geertje Van Rangelrooij-> Cornelia Gerrits de Jong-> Annigje Floris Bogerd-> Geertje Craijenbos (born 1705).  However, since you are a male, and not able to pass on your mitochondrial DNA, your daughters all belong to a different haplogroup from you.  They belong to Ginny's haplogroup, which is the same as her mother's, and her mother's and her mother's, etc.

One other curious note in our genealogy.  Our ancestor Annigje Floris Bogerd,  Great-great grandmother of Geertje Roest, is from the Bogert-Bogaaert-Boogard family. One source I have found, which I have not confirmed, has a connection of Humphrey Bogart to the DeKornes.  He would be your mother's tenth cousin.  

https://www3.nationalgeographic.com/genographic/index.html