I would say Australopithecus because so far, its skull is the one that resembles the most that of a human's.
        
             
        
        
        
Answer: Small animals such as ants, some species of mice and rats, and cockroaches. 
Explanation:
The smaller the animal is, the better chance it has to survive in drastic environmental change. (They will not be affected as much because of their size) Hope this helps :)
 
        
             
        
        
        
I would say A. Because it seems like a logical explanation.
        
                    
             
        
        
        
Some scientists hypothesize that the eukaryotic cells are really the result of symbiotic processes! 
Specifically, the internal organs of the cells could be a remnant of a symbiotic relationship in which one cell lived inside of another cell. These two cells then both split upon reproduction and eventually the cell inside was reduced to an organelle. 
But according to this theory, it is very likely that the prokaryotic cells engaged in a number of symbiotic relationship, and that this actually lead to the emergence of eukaryotic cells!
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