The phylum Echinodermata , which contains about 6000 species, gets its name from the Greek, literally meaning "spiny skin." Many echinoderms actually do have "spiny" skin, but others do not. This phylum exists exclusively in the sea, and cannot be found on land or in fresh water.
        
                    
             
        
        
        
The answer is “Variation that decrease reproductive success are more likely to be passed on.”
        
             
        
        
        
Is this science?? Also may I hv options.