With these cluster analyses, it is true that the most similarities examined are shared within a group, but plenty overlap with other clusters. The graphical representations of these types of data show blending at the edges. The sharpest delineations coincide with water: Europe, sub-Saharan Africa, and East Asia. But with the addition of more groups, with fewer oceanic gulfs, human variation is pretty continuous. The concept of a discrete or pure race vanishes in the haze.
