This example presents an interactive, animated tree diagram showing a biological classification of animals, from the root “Animals” down through vertebrates and invertebrates to specific groups like Mammals, Birds, and Insects. Built with D3.js version 3, it uses `d3.layout.tree` and `d3.svg.diagonal` to compute the hierarchical layout and draw curved links between nodes. The SVG rendering includes colored node strokes and text labels, with a 750-millisecond transition animation on update. The dataset is hardcoded as a JavaScript array with hierarchical parent-child relationships.