Over the weekend, I was contacted by a cousin from a long lost branch of the family, which had severed ties back in the sixties. She and her father had started doing research into their family tree, since most of the information that they had was lost when her grandfather died. She stumbled across a partial family tree that I had uploaded to Ancestry back in 2013, and realized that our great grandmothers were sisters. I mentioned her to my grandmother, and she was full of stories of her childhood with the cousins of that generation prior to the schism; my cousin in turn had some stories featuring my great aunt and my great grandmother from before when my grandmother was born.
I’ve been experimenting with Mermaid.js for a visual representation of the genealogical history that my grandmother started in the seventies, and which she digitized in the early 2000s. I’d ultimately like to convert all of it to a more durable plaintext format, since the files are currently in .doc format. My latest efforts, though, have been learning about genealogical numbering systems in order to develop a consistent, well structured index for the data that I’m inputting to the Mermaid flowchart. My grandmother’s records all use the Henry System, a descending system that works quite well for capturing the full scope of a family with a shared common ancestor. But to build a family tree in the other direction, and so to bring together four different family trees for each of my four grandparents, simply using the Henry numbers as indices doesn’t work, since the same person can show up in multiple trees with a different identifier in each (for instance, I am 1114321, 11362621, and 1634321 across three of the trees in which my name appears). My Mermaid tree is using an Ahnentafel (ancestor table) instead, which is an ascending method that makes for a much cleaner markdown source file. Indeed, though I’m using the table to produce a tree, the data structure is meaningful in itself, whether or not it is diagrammed, and ideal for plaintext. As Wikipedia puts it: “an ahnentafel is a method for storing a binary tree in an array by listing the nodes (individuals) in level-order (in generation order).” As a “functional theory of numeration,” it’s a fascinating artifact, and a surpisingly useful tool in this digital age.
The principles of the Ahnentafel method were first published in 1590 by Michaël Eytzinger, and thinking about this duration, and the duration between myself and some of my oldest recorded ancestors, brings the seventh generation principle to mind, requiring that I consider just how radical the principle is. My ancestors of the seventh generation were born around 1800, and could not have conceived of the life that their seventh great grandson lives. Seven generations from now will take us to the 2200s, and I, similarly, cannot conceive of the lives any potential seventh great grandchildren of mine might live. Catastrophic climate change by 2030, global food system collapse by 2050—these dates simultaneously remain at a distance and yet present an unavoidable, inevitable horizon, a horizon that is less a firm boundary and more a temporal oil spill leaking into the present. The year 2200 feels inconceivable. And yet, it is precisely the work of imagining an earth without us that is necessary for us to properly orient ourselves toward the emergency at hand, and so make possible a conception of an earth with us for those yet to come, seven generations from now.