Inside a population, the presence of many different alleles means there will almost always be an individual with a specific MHC molecule able to load the correct peptide to recognize a specific microbe. The evolution of the MHC polymorphism means that a population will not succumb to a new pathogen or a mutated one, because at least some individuals will be able to develop an adequate immune response to defeat the pathogen. The variations in the MHC molecules are the result of the inheritance of different MHC molecules.