The range of the Turks’ diversity has narrowed as time has passed

The range of the Turks’ diversity has narrowed as time has passed, more
so under some headings than others. Among axes of differentiation that figure
prominently in discussions of Turkic origins, the one that has changed
least in the aggregate is diversity of physical type. In genetic makeup, the
Turkic peoples have mixed both relevant categories, European and East
Asian, from the beginning. Variations across space and time are wide; yet
the aggregate picture cannot vary beyond the mixing and remixing of two
categories that were already in contact to start with. What is not to be found
anywhere is the racial purity that used to appear in pan-Turkist writings.
Turkic communities were “polyethnic and political in character” from the
beginning.2 However, although the variety of genetic types available for
mixing could not vary beyond a certain range, the bearers of those genes
brought different cultures with them; and this fact has greatly heightened
Turkic diversity in a way that genetic data alone cannot convey.