Example image of eyePlorer eyePlorer map for 'Cline (biology)': Biology Community Ecotone Julian Huxley Ecotype Phenotype Polymorphism (biology) Allele frequency Gene pool Taxon Gradient analysis Anthropology Human genetic variation Race (classification of human beings) Latitude Tropics Subspecies Allele Evolution Haplotype Population genetics Ring species Species Speciation Larus Chemistry Chemocline Density Halocline Pycnocline Salinity Temperature Thermocline Scaled Ground-cuckoo Intergradation Isolation by distance White-tailed Iora Environmental gradient Green-bellied Hummingbird Rufous-vented Ground-cuckoo Form (zoology) Parapatric speciation Lesser Goldfinch Kostenki Hybrid zone Multiregional origin of modern humans Turnover-pulse hypothesis European Starling Trichoniscus pusillus Buff-tailed Sicklebill