Answer:
A question is never clear 
 
        
             
        
        
        
Answer:
The temperature of something would be how hot or cold the object is 
 
        
             
        
        
        
I would say immigration only.
emigration would theoretically reduce the genetic variation as unique individuals leave, but immigration would bring unique traits into circulation in an ecosystem.
I'm not super great at biogy tho so this might not be right... :)