title: Protein polymorphism and fluctuation of environments.
mesh_terms: D000483:Alleles; D000818:Animals; D005075:Biological Evolution; D004330:Drosophila / Q000235:genetics; D004586:Electrophoresis; D004777:Environment; D005796:Genes; D005838:Genotype; D006579:Heterozygote; D006801:Humans; D008433:Mathematics; D008954:Models, Biological; D011110:Polymorphism, Genetic; D011506:Proteins / Q000235:genetics*
chemical_list: D011506:Proteins