There is only one Caucasian.
Johann Friedrich Blumenbach, the “father of craniology”, “coined the word Caucasian to describe the white race. It is curious that this word– which is still widely used– is based upon a single skull in Blumenbach’s collection which came from the Caucasian mountain region of Russia. Blumenbach found strong resemblances between this skull and the crania of Germans. Therefore, he conjectured that possibly the Caucasus regions may have been the original home of the Europeans.”
~ Thomas F. Gossett, Race: The History of an Idea in America, p. 37-8