Darwin's theory. In 1859, Charles Darwin set out his theory of evolution by natural selection as an explanation for adaptation and speciation. He defined natural selection as the "principle by which each slight variation [of a trait], if useful, is preserved".
 
        
             
        
        
        
The answer is, 
d<span>istal convoluted tubule (dst)</span>
        
             
        
        
        
Formation of new cells from pre existing cells
        
             
        
        
        
Maybe because they like coacervates.