normal functioning genes, a single mating would produce several phenotypically different offspring, making the ability for mimicry to evolve very difficult. This unique puzzle led to proposal of a possible supergene. A supergene is a tight cluster of loci that facilitate the co-segregation of adaptive variation, providing integrated control of complex adaptive phenotypes. Different genomic rearrangements have tightened the genetic linkage between different color and pattern loci with complete suppression of recombination in experimental crosses in a 400,000 base section containing at least 18 genes. This single supergene locus controls differences in a complex phenotype like wing coloration that can involve modifications of wing pattern, shape, and body color. Mimetic patterns have high fitness correlated to locally abundant wing patterns and low fitness when the offspring have recombinant, non-mimetic phenotypes. This tight-linked area of wing pattern genes explains how mimetic phenotypes are not broken up during recombination during sexual reproduction. Polymorphism Viceroys display geographic color polymorphism, which occurs when the viceroy butterflies are observed having different color forms in different regions of their territory. Color polymorphism is hypothesized to be affected by interaction between the viceroy, monarch and queen's overlapping environments. In the northern areas of their region, where monarchs predominate, viceroys are lighter, while in southern Florida, they are darker due to queens being more abundant than monarchs. References Further reading Glassberg, Jeffrey Butterflies through Binoculars, The West (2001) Guppy, Crispin S. and Shepard, Jon H. Butterflies of British Columbia (2001) James, David G. and Nunnallee, David Life Histories of Cascadia Butterflies (2011) Pelham, Jonathan Catalogue of the Butterflies of the United States and Canada (2008) Pyle, Robert Michael The Butterflies of Cascadia (2002) External links Description of Viceroy on Butterflies and Moths website viceroy butterfly on the UF / IFAS Featured Creatures Web site Viceroy, Butterflies of Canada Limenitis Butterflies of North America Butterflies described in 1776 Nymphalidae of South America Insects of the Arctic Symbols of Kentucky