polymorphism The term polymorphism refers to the presence of alleles in population. A population or species may be polymorphic for color. as in snails. or for some biochemical function. as in plant toxicity. Some polymorphisms are maintained by natural selection, but others appear to result from the effect of many genes controlling the polymorphic character Measuring genetic Genetic variation within populations and species can be variation estimated directly from the dNa or from protein(allozyme) variation Proteins or DNA fragments are separated by gel electrophoresis to give bands that can be scored to determine the genotype of individuals. Detailed investigation of the DNA of individuals yields a unique genetic fingerprint, useful for establishing paternitypolymorphism The term polymorphism refers to the presence of alleles in a population. A population or species may be polymorphic for color, as in snails, or for some biochemical function, as in plant toxicity. Some polymorphisms are maintained by natural selection, but others appear to result from the effect of many genes controlling the polymorphic character. Genetic variation within populations and species can be estimated directly from the DNA or from protein (allozyme) variation. Proteins or DNA fragments are separated by gel electrophoresis to give bands that can be scored to determine the genotype of individuals. Detailed investigation of the DNA of individuals yields a unique genetic fingerprint, useful for establishing paternity. Measuring genetic variation