Due to the finches' habitat and their how they have to adapt to it. If there were different ways of eating etc, they would have a different styled beak to suit that adaptation.
Hope it helps.
 
        
             
        
        
        
<span>Answer: 1%</span>
<span>As per excerpts, Water covers 75 percent of Earth and  97 percent of water on Earth is salt water, meaning only 3 percent of water is available as fresh water. Based on this information, 3% of 75% of the water on earth is available as fresh water or 2.25%. Since most of the water is said to be locked up in solid glaciers and polar ice caps,  the amount of water on the planet that is available for animals to drink is lesser than 2.25% so the best approximation is 1 percent.</span>
 
        
                    
             
        
        
        
Genetic Variation
Natural selection results in organisms that are better suited to their environment are able to pass on genes to create strong offspring
        
                    
             
        
        
        
They produce oxygen they are used as shelter, they are used for blocking the shade, they sustain other animals that sustain the planet and us.