World countries by ethnic diversity

A revealing map of the world's most and least ethnically diverse countries
https://www.washingtonpost.com/news/worldviews/wp/2013/05/16/a-revealing-map-of-the-worlds-most-and-least-ethnically-diverse-countries/

Most diverse: Uganda
Most homogenous: Japan and the Koreas

-It is interesting that the US "melting pot" only has average ethnic diversity
-Several of the most homogenous are geographically isolated ex. Nordic, NW Europe, Australia, Japan and Koreas