Mmi in tJie Light of Evolution 



" adaptive radiation," ^ or divergence in all di- 

 rections, mitigates the severity of competition 

 within the species or group, opens new doors for 

 survival, and gives the possibility of progress or 

 degeneration. It enables the weaker form to 

 discover a harbor of refuge and here survive, as 

 it could nowhere else. Fresh water and the deep 

 sea have always been the refuge of defeated 

 forms. 



This tendency has its dangerous side. The 

 animal is continually tempted to forsake the up- 

 ward line of march, and to seek some easier or 

 more attractive path. Alluring side paths are 

 very numerous and always open. Every new at- 

 tainment of the animal gives it the opportunity 

 for new experiments and adaptations. Every 

 stage Is a center from which forms radiate in all 

 directions seeking surer survival or easier life. 



But usually only one path, one set of habits, 

 adaptation to only one group of surroundings, 

 leads to progress and fitness. All others lead to 

 stagnation or degeneration. Temporary sur- 



^ Osbom, H. F., "Adaptive Radiation," Amer. Nat., vol. 

 xxxvi, 1902, p. 353. See also articles in vols, xxxvii and 

 xxxviii. 



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