A fork of a family tree example demonstrates a hierarchical animal classification using a tree layout with animated SVG circles and links. The visualization shows categories like Herbivorous, Carnivorous, and Omnivorous branching into specific animals, with circle colors indicating generation depth. Built with D3.js v6, the code uses `d3.stratify()` to convert flat data into a hierarchy, `d3.tree()` to compute positions, and `transition()` to animate link paths and circle radii over durations. Node labels appear as bold white text, and all elements are centered within the viewport.