Division of Labor 331 



in October and travel to their winter quarters along the California 

 coast (Allen, 1870). With this social organization in operation 

 among the fur seals, the non-breeding males can be killed for their 

 pelts without reducing the productivity of the herd; hunting is re- 

 stricted in this way by international agreement. Similar organization 

 of the herd into harems during the breeding season and into larger 

 non-family groups during other parts of the year is found among the 

 European red deer, Cervus elaphus (Darling, 1937) and among the 

 American elk or wapiti, Cervus canadensis ( Murie, 1951 ) . 



The most complex types of division of labor are exhibited by man 

 himself and by certain insects. The division of labor in man is a 

 learned behavior and occurs without structural modification. In com- 

 plete contrast, the behavior exhibited by members of an insect colony 

 is instinctive and the individuals performing various functions in the 

 colony are specialized morphologically and physiologically (Fig. 

 9.10). This differentiation of members of the same species is devel- 

 oped to its greatest extent among the termites and ants (Wilson, 

 1953). Since the division of labor in an insect colony is accompanied 

 by structural specializations and instinctive behavior, it is less flexible 

 than that occurring in mammalian groups, and especially in man's so- 

 ciety. This fact and theii- size limitations have no doubt largely pre- 

 vented the insects from attaining a more dominant position in the 

 world. 



Among groups of animals all degrees of integration exist from 

 aggregations with no organization to highly elaborated societies. 

 Allee (1951) has developed the theory that societies have evolved 

 from aggregations. If the existence of a group confers definite sur- 

 vival value on the individuals, the group will tend to persist. Those 

 reactions that lead to the formation of the group will also persist, 

 and these will constitute the beginning of social behavior. The co- 

 operation that we now observe among the individuals may have 

 resulted as a consequence of the formation of the group. The 

 division of labor appeared as chance variation and persisted because 

 of its survival value; it is not necessarily conscious nor purposeful. 



According to the foregoing ideas the elaborate social organization 

 found among a few species may therefore have evolved through the 

 following steps. First, others of the same species are tolerated in a 

 restricted space and then definite reactions to their presence are de- 

 veloped. If survival values result either through behavior or physio- 

 logical adjustments, a tendency for an increase in the permanency of 

 the group will exist. Following this, a further development of the or- 



