Thus, Heliconius pattern diversity could be facilitated by the movement of pre-established colour pattern adaptations [ 20, 22, 23].
Under this scenario, some of the diversity of mimicry rings achieved by Heliconius lineages could be due to their ability to exchange fully formed colour pattern adaptations between closely related species [ 73, 74]; in Gilbert's metaphor, hybridization supplies Heliconius species with an interspecific "shared toolkit" of mimicry genes [ 47].
The pair of protective bracteoles become hard, and the seed is also surrounded by fleshy bracts that may become ivory, red, or orange in colour, perhaps an adaptation for animal dispersal.
Receptor adaptation and colour constancy make colour vision robust and well suited for object classification and identification [ 3].
Living fossil conjures up the idea of long-lived species or organisms out of time longing for the good old days of the Devonian and disdainful of whippersnappers with their colour vision and adaptations to human pollution.
Earlier ornithologists felt that the kakapo might be related to the ground parrots and night parrot of Australia due to their similar colouration, but this is contradicted by recent studies; rather, the cryptic colour seems to be adaptation to terrestrial habits that evolved twice convergently.
The ranking order was polishability < marginal adaptation < colour match, based on their mean alpha values.
Under the second scenario, an initial divergence in colour pattern associated with adaptation to different Müllerian mimicry rings became associated with further changes in ecology and hybrid inviability, eventually leading to speciation [ 12].
In addition, receptor adaptation contributes to colour constancy, the ability to maintain object colour appearance independent of the illuminating spectrum.
Patterns may be startling (dymantic), as seen in the mane of the male lion or hamadryas baboon, warning (sematic), as seen in the bold pattern of skunks, or concealing (cryptic), perhaps the most common adaptation of pelage colour.
