THE EVOLUTION OF ANTS 



derives a certain protection from living near its neighbors. 

 A careful study of these habits of ants has shown that 

 they can be explained only as the results of a gradual 

 and complicated evolution. This form of evolution has led 

 to a peculiar degeneration of some parasitic species, 

 which have, in fact, 

 become abjectly de- 

 pendent on the host 

 for food, for the 

 care of the brood, 

 and for the con- 

 struction of the nest, 

 and some ants have 

 even lost completely 

 their worker caste. 

 The strong convic- 

 tion of naturalists 

 that such parasites 

 have been evolved 

 from once independ- 

 ent organisms in- 

 stead of having 

 been created in their 



present dependent and degenerate form should be carefully 

 weighed by all those who are busily attacking evolution in 

 the name of religion and morality. 



That the activities of ants in response to particular 

 environments have led to the development of highly special- 

 ized habits is shown also by many interesting examples of 

 "convergent" or "parallel" evolution in species that are not 

 closely related. One striking example is furnished by the 

 tropical ants that inhabit silken nests on trees. These nests 

 are really constructed by the young larvae, which their worker 



[221] 



Fig. 7. — A weaver-ant (Oecophylla 

 lo?iginoda) of the Congo: a, major worker 

 in profile, with legs removed; b, head of 

 major worker from above; c, minor 

 worker; d, head of minor worker. 



