Example image of eyePlorer eyePlorer map for 'Ring species': Biology Evolution Species Cline (biology) Hybrid (biology) Larus North Pole Siberia Europe Caspian Gull Glaucous Gull Superspecies Yellow-legged Gull California Central Valley (California) Ensatina Greenish Warbler Himalayas Salamander Herring Gull Powelliphanta Lesser Black-backed Gull Parapatric speciation Vagueness Gull Ecotype Polymorphism (biology) Coal Tit Introduction to evolution Julian Huxley