henotypic lasticity
easonal olyphenism
Studies involving the phenotypic plasticity - the ability to easily alter phenotype - of Bicyclus anynana butterflies demonstrate the small number of genes involved in the patterning of butterfly wings.
B. anynana butterflies show seasonal polyphenism - they exist in two very different forms determined by the time and temperature of development.
Those butterflies mature during the wet-season lead an active existence.
Large and conspicuous pattern elements on the ventral sides of their hindwings, exposed in a resting position, serve as warnings to predators.
In the dry-season, camouflage increases the butterflies' chance of survival; reduced or absent pattern elements characterize the ventral sides of their hindwings.
A developing larva possesses the ability to display either of the two seasonal forms, as shown in the laboratory by controlling the temperature of development.
The ability of the larva to respond to environmental factors disappears by the twentieth generation
if the butterflies are selectively bred for the size of their eyespots to create LOW and HIGH lines.
Hormones controlling gene expression mediate the development of the two seasonal forms.
The wet season form of Bicyclus anynana
The dry season form of Bicyclus anynana
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