Answer and Explanation:
Many elements can be responsible for this, among them, we can mention the presence and absence of predators in the different places on the rocky coast. This is because predators can influence not only the number of organisms found, but also the types of organisms.
Another element that may be the cause of this variability is the availability of resources necessary for the life of these organisms, in addition, the impact of the waves on the rocks, can cause the variability of the organisms, since some may not be able to resist the impact of the waves.
Natural Selection.
It favors the better adapted organisms.
Answer: Hereditary carrier or carrier
A hereditary carrier is a person or an organism that has inherited a recessive allele. Alleles are pairs or series of genes on a chromosome that determines hereditary characteristics. Carriers have the genetic trait but do not show the trait or show symptoms of any disease.