An unusual case of implexity
In this article, we’ll describe an example of an implex, a situation that is sometimes encountered in genealogy. However, the case studied here occurs only rarely.
But first, let’s explain what an implex is in genealogy. According to Wikipedia, “An implex in a family tree is the same ancestor appearing in several places in the tree“. Here’s an example featuring a couple, Antoine Dupont and his wife Anne Merlin, who are twice great-grandparents of Paul Dupont:
These two people, identified in the tree by labels “a” and “b”, are the parents of Paul’s paternal grandfather, Etienne Dupont, and Paul’s maternal grandmother, Lucie. Paul is thus twice descended from Antoine and Anne.
Clearly, the notion of implexity is linked to that of consanguinity. The example given above is a fiction that has been created over 4 generations to obtain a small tree.
Let’s now look at a real ascending genealogy, that of Mrs Marie DASSING. It is represented below by a half-wheel on which it is possible to highlight the implexity by using the red color for the couple present 2 times in the ancestry. These are Michel Dasy and Elisabeth Kieffer, who are paternal great-great-grandparents on the one hand, and maternal great-grandparents on the other. The particularity of this implex is that this couple appears on two different generations in Marie’s ancestry. As a result, Marie’s parents Frédéric Dassing and Marguerite Gerold are 2nd Cousin, 1x Removed.
Under French law, an exemption from consanguinity is only required up to the 4th degree of family relationship (marriage between first cousins, for example)..
