<span>The somatic nervous system is known as the voluntary nervous system, is a part of the peripheral nervous system. It consists of neurons that are associated with skeletal or striated muscle fibers. It affects voluntary signaling for many resion. A large part of the PNS is composed of 12 pairs of cranial nerves and 31 pairs of spinal nerves.</span>
        
             
        
        
        
Cause mammals are the only species that are well developed before birth unlike marsupial and monotremes 
 
        
             
        
        
        
Answer:
Please see below
Explanation:
Adapting to the surrounding environment is a critical part of surviving and, eventually, evolution. Take mice as an instance. Their coat color plays a major role in allowing to go undetected from potential predators if they are able to blend in well with the surrounding environment. Mice with a coat color that makes them stand out will be easily preyed on. Hence, those who have <u><em>adapted</em></u> to their environmental conditions will live to pass on their genes. This phenomenon is known as selection pressure.