This example displays a scatter plot of the Iris dataset, plotting petal length on the x-axis and petal width on the y-axis, with each point colored by species (skyblue, lightgreen, or orange). It also encodes sepal length and width as the horizontal and vertical radii of each circle, creating an elliptical marker for each observation. The visualization loads CSV data from a GitHub gist using `d3.csv` and renders SVG circles via D3 v6 selections with `join`. Axes are generated using `d3.axisLeft` and `d3.axisBottom`, while scales are created with `d3.scaleLinear` and domains from `d3.extent`.