This visualization shows a world map with countries colored by population using a threshold scale, rendered as SVG paths via `d3.geoPath` with a Mercator projection. The choropleth uses a quantized color range from light to dark blue, and hover interactions trigger tooltips built with `d3-tip`, displaying each country’s name and population. Data comes from a TopoJSON file and a TSV of population figures, both loaded asynchronously with the queue library.