Answer:
Evolution is a change  in the inheritable phenotypic characters within a population occurs through successive generations.
Explanation:
Evolution is a change in inheritable characters of population during a period of time by means of natural selection. These changes in phenotypic characters brings the formation of new species. Darwin's theory consists of three categories,individuals within a group are variables, variations are inheritable,all individuals with variables survive. 
According to Darwin's theory states that survival is based on selective mode like particular phenotypic characteristics or behavior given to some individuals who are able to survive in a particular environment.
 
        
             
        
        
        
When a lineage splits into multiple line of descents, then, it leads to speciation. It is a process by which a single population evolves into different species.  The process of speciation leads to the development of two or more species as  the lineages are splitted. These two evolved species are genetically independent.
Hence, the blank can be filled with 'speciation'.
 
        
                    
             
        
        
        
Answer:
They have a backbone, most use legs,wings,or fins for movement. 
 
        
                    
             
        
        
        
Answer:
can you do another post zooming it in
Explanation: