This example visualizes the Iris dataset using a scatter plot of petal length versus petal width, colored by species. It uses D3.js v6 with the `csv`, `select`, `scaleLinear`, `extent`, `axisLeft`, and `axisBottom` APIs to fetch data, scale axes, and render the SVG. The plot also encodes sepal dimensions as `rx` and `ry` attributes on circles, though the rendering effect is not configured. Data is loaded from a remote GitHub Gist via D3's `csv` function.