A vertical family tree displays three generations of descendants from a single ancestor, with each node represented by a labeled circle. The visualization uses D3’s `d3.stratify()` to convert the flat `{child, parent}` data into a hierarchy, then applies the `d3.tree()` layout algorithm to position nodes top-down. Parent-child connections are drawn as paths using `d3.linkVertical()`, and the SVG output is rendered with the `join` API. The tree includes 36 individuals, branching into four main subfamilies.