Exaggeration and suppression of iridescence: the evolution of two-dimensional butterfly structural colours

Many butterfly species possess ‘structural’ colour, where colour is due to optical microstructures found in the wing scales. A number of such structures have been identified in butterfly scales, including three variations on a simple multi-layer structure. In this study, we optically characterize examples of all three types of multi-layer structure, as found in 10 species. The optical mechanism of the suppression and exaggeration of the angle-dependent optical properties (iridescence) of these structures is described. In addition, we consider the phylogeny of the butterflies, and are thus able to relate the optical properties of the structures to their evolutionary development. By applying two different types of analysis, the mechanism of adaptation is addressed. A simple parsimony analysis, in which all evolutionary changes are given an equal weighting, suggests convergent evolution of one structure. A Dollo parsimony analysis, in which the evolutionary ‘cost’ of losing a structure is less than that of gaining it, implies that ‘latent’ structures can be reused.

[1]  W. Fitch.  Toward Defining the Course of Evolution: Minimum Change for a Specific Tree Topology , 1971 .

[2]  Peter Vukusic,et al.  Grazing-incidence iridescence from a butterfly wing. , 2002, Applied optics.

[3]  C. Kittel.  Introduction to solid state physics , 1954 .

[4]  R. Vane-Wright,et al.  16. The Butterflies: Hedyloidea, Hesperioidea and Papilionoidea , 1998 .

[5]  M F Land,et al.  The physics and biology of animal reflectors. , 1972, Progress in biophysics and molecular biology.

[6]  A. Parker,et al.  A unique form of light reflector and the evolution of signalling in Ovalipes (Crustacea: Decapoda: Portunidae) , 1998, Proceedings of the Royal Society of London. Series B: Biological Sciences.

[7]  S Enoch,et al.  Morpho butterflies wings color modeled with lamellar grating theory. , 2001, Optics express.

[8]  Adrian Cho,et al.  Electronic Paper: A Revolution About to Unfold? , 2005, Science.

[9]  R. Wootton,et al.  Quantified interference and diffraction in single Morpho butterfly scales , 1999, Proceedings of the Royal Society of London. Series B: Biological Sciences.

[10]  M. Hutley,et al.  The Optical Properties of 'Moth Eye' Antireflection Surfaces , 1982 .

[11]  Rodolfo H. Torres,et al.  Structural colouration of avian skin: convergent evolution of coherently scattering dermal collagen arrays , 2003, Journal of Experimental Biology.

[12]  J. Sambles,et al.  Photonic structures in biology , 2003, Nature.

[13]  N. Wahlberg,et al.  Towards a better understanding of the higher systematics of Nymphalidae (Lepidoptera: Papilionoidea). , 2003, Molecular phylogenetics and evolution.

[14]  H. Ghiradella.  Light and color on the wing: structural colors in butterflies and moths. , 1991, Applied optics.

[15]  H. Ghiradella,et al.  Structure of Iridescent Lepidopteran Scales: Variations on Several Themes , 1984 .

[16]  A. Parker.  Discovery of functional iridescence and its coevolution with eyes in the phylogeny of Ostracoda (Crustacea) , 1995, Proceedings of the Royal Society of London. Series B: Biological Sciences.

[17]  F. Micheron.  Non Conventional Approaches to Reflective Color Displays , 2006 .

[18]  R. Wootton,et al.  Limited-view iridescence in the butterfly Ancyluris meliboeus , 2002, Proceedings of the Royal Society of London. Series B: Biological Sciences.

[19]  H. Nijhout,et al.  The development and evolution of butterfly wing patterns , 1991 .

[20]  S. Kinoshita,et al.  Mechanisms of structural colour in the Morpho butterfly: cooperation of regularity and irregularity in an iridescent scale , 2002, Proceedings of the Royal Society of London. Series B: Biological Sciences.

[21]  A. Parker.  A geological history of reflecting optics , 2005, Journal of The Royal Society Interface.

[22]  K Lieberman,et al.  Simple method for focusing x rays using tapered capillaries. , 1988, Applied optics.

[23]  Rodolfo H. Torres,et al.  Blue integumentary structural colours in dragonflies (Odonata) are not produced by incoherent Tyndall scattering , 2004, Journal of Experimental Biology.

[24]  H. Ghiradella,et al.  Structure and Development of Iridescent Lepidopteran Scales: the Papilionidae as a Showcase Family , 1985 .

[25]  K. Maekawa,et al.  Molecular Phylogeny of Birdwing Butterflies Based on the Representatives in Most Genera of the Tribe Troidini (Lepidoptera: Papilionidae) , 1999 .

[26]  M. Parsons.  A phylogenetic reappraisal of the birdwing genus Ornithoptera (Lepidoptera: Papilionidae: Troidini) and a new theory of its evolution in relation to Gondwanan vicariance biogeography , 1996 .

[27]  A. Brower.  Phylogenetic relationships among the Nymphalidae (Lepidoptera) inferred from partial sequences of the wingless gene , 2000, Proceedings of the Royal Society of London. Series B: Biological Sciences.

[28]  Shuichi Kinoshita,et al.  Wavelength–selective and anisotropic light–diffusing scale on the wing of the Morpho butterfly , 2004, Proceedings of the Royal Society of London. Series B: Biological Sciences.

[29]  L. Plattner.  Optical properties of the scales of Morpho rhetenor butterflies: theoretical and experimental investigation of the back-scattering of light in the visible spectrum , 2004, Journal of The Royal Society Interface.

[30]  M. Majerus,et al.  Ultraviolet colours in butterflies: intra- or inter-specific communication? , 1995, Proceedings of the Royal Society of London. Series B: Biological Sciences.

[31]  H. Ghiradella,et al.  Structure and development of iridescent butterfly scales: Lattices and laminae , 1989, Journal of morphology.

[32]  Max Born,et al.  Principles of optics - electromagnetic theory of propagation, interference and diffraction of light (7. ed.) , 1999 .

[33]  K. Brown,et al.  Phylogeny of the Nymphalidae (Lepidoptera). , 2004, Systematic biology.

[34]  J. Farris.  Phylogenetic Analysis Under Dollo's Law , 1977 .