The Xavante Indians of Brazil have head shapes which differ from their neighbors. The researchers were surprised by the rapid variation that occured within this tribe. Of course this variation hasn't led to "evolution"-nor can it-since the indians are still homo sapiens. Rather this variation represents the built-in diversity within the human gene pool. The Xavante split from the Kayapo about one & a half thousand years ago.
And hath made of one blood all nations of men for to dwell on all the face of
the earth,... Acts 17:26