Callous is another way to say it
        
                    
             
        
        
        
The evolution of sexual reproduction is a great puzzle in modern evolutionary biology. Many groups of eukaryotic organisms, especially most animals and plants, reproduce sexually. The evolution of sex between two organisms of the same species contains two related but different themes: its origin and its maintenance. However, since hypotheses for the origin of sex are difficult to test experimentally, most of the current work has focused on the maintenance of sexual reproduction. Biologists, including W. D. Hamilton, Alexei Kondrashov, and George C. Williams, have proposed various explanations for how sexual reproduction is maintained in a large set of different living things.
        
             
        
        
        
rose thorns are multicellular 
i hope this helps! :)
 
        
                    
             
        
        
        
Answer:
The cold, northern currents then flow in a rotating current system called the North Atlantic subpolar gyre, of which the Labrador Current is the southward flowing component. 
                                                          OR
The Gulf Stream is an intense, warm ocean current in the western North Atlantic Ocean. It moves north along the coast of Florida and then turns eastward off of North Carolina, flowing northeast across the Atlantic.
Explanation:
Idk if this is right but hopefully it is...