Carl Sagan, Dragons of Eden: Speculations on the Evolution of Human Intelligence

Those mothers with hereditary large pelvises were able to bear large-brained babies who because of their superior intelligence were able to compete successfully in adulthood with the smaller-brained offspring of mothers with smaller pelvises.

Carl Sagan, Dragons of Eden: Speculations on the Evolution of Human Intelligence

Those mothers with hereditary large pelvises were able to bear large-brained babies who because of their superior intelligence were able to compete successfully in adulthood with the smaller-brained offspring of mothers with smaller pelvises.

Carl Sagan, Dragons of Eden: Speculations on the Evolution of Human Intelligence

Those mothers with hereditary large pelvises were able to bear large-brained babies who because of their superior intelligence were able to compete successfully in adulthood with the smaller-brained offspring of mothers with smaller pelvises.