In order to be able to pursue such a variety of economic options, fluid homeland territories have been preferred over fixed ones.  Although a somewhat fixed center of gravity may prevail, the outer boundaries of homeland terrirories are continually changing to accommodate new social, economic, or environmental realities.  By this means, tribal groups have been able to insure against losses due to environmental or socio-political setbacks and to expand opportunities for trade and cooperative relationships where desireable.

Reference: http://www.hf-fak.uib.no/smi/paj/LaBianca.html

 

 

Edited 1/26/06 tlc