Because one of them dies and another one doesn’t
        
             
        
        
        
Answer:
Phalanges: long bones
Sternum: flat bone
Vertebrae: Irregular bone
 
        
             
        
        
        
Evolution would least likely be a cause of natural selection.
Natural selection has to do with the survival of the fittest. Therefore, adaptation, variation, and overpopulation all have an impact on natural selection - those who do not adapt to their new surroundings due to overpopulation or those whose bodies have not modified enough will not survive.