Answer:
Because the biodiversity decreases. 
Explanation:
An ecosystem is richer when it has a higher biodiversity, remember that each living thing has an specific role in the food web. When in an ecosystem this web is bigger, increases the probability of sustain a living thing. For example, in the sea, if there is a fish, this is going to be more probabilities of survive if this fish can eat different plants or other fish. But if in the ecosystem there are not a variety of them, it probability to survive is less if one of it food desapear. 
 
        
             
        
        
        
Because it helps the environment strive and keep its self alive my controlling populations and bringing in new ones
        
             
        
        
        
1) The function of a protein is determined by its shape. The shape of a protein is determined by its primary structure. The sequence of amino acids in a protein is determined by the sequence of nucleotides in the gene DNA encoding it.
        
             
        
        
        
Answer:
Climate change leading to increases in ocean temperatures, evaporation of seawater, and glacial and sea ice melting could create an influx of warm freshwater onto the ocean surface. This would further block the formation of sea ice and disrupt the sinking of denser cold, salty water.
Explanation:
 
        
             
        
        
        
The medicine want advanced enough to fight off the sicknesses and doctors weren't very knowledgeable