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Color Patterns (color + pattern)
Selected AbstractsCOEVOLUTION OF COLOR PATTERN AND THERMOREGULATORY BEHAVIOR IN POLYMORPHIC PYGMY GRASSHOPPERS TETRIX UNDULATAEVOLUTION, Issue 2 2002Anders Forsman Abstract Ectothermic organisms, such as insects and reptiles, rely on external heat sources to control body temperature and possess physiological and behavioral traits that are temperature dependent. It has therefore been hypothesised that differences in body temperature resulting from phenotypic properties, such as color pattern, may translate into selection against thermally inferior phenotypes. We tested for costs and benefits of pale versus dark coloration by comparing the behaviors (i.e., basking duration and bouts) of pygmy grasshopper (Tetrix undulata) individuals exposed to experimental situations imposing a trade-off between temperature regulation and feeding. We used pairs consisting of two full-siblings of the same sex that represented different (genetically coded) color morphs but had shared identical conditions from the time of fertilization. Our results revealed significant differences in behavioral thermoregulation between dark and pale individuals in females, but not in males. Pale females spent more time feeding than dark females, regardless of whether feeding was associated with a risk of either hypothermia or overheating. In contrast, only minor differences in behavior (if any) were evident between individuals that belonged to the same color morph but had been painted black or gray to increase and decrease their heating rates. This suggests that the behavioral differences between individuals belonging to different color morphs are genetically determined, rather than simply reflecting a response to different heating rates. To test for effects of acclimation on behaviors, we used pairs of individuals that had been reared from hatchlings to adults under controlled conditions in either low or high temperature. The thermal regime experienced during rearing had little effect on behaviors during the experiments reported above, but significantly influenced the body temperatures selected in a laboratory thermal gradient. In females (but not in males) preferred body temperature also varied among individuals born to mothers belonging to different color morphs, suggesting that a genetic correlation exists between color pattern and temperature preferences. Collectively, these findings, at least in females, are consistent with the hypothesis of multiple-trait coevolution and suggest that the different color morphs represent alternative evolutionary strategies. [source] The insertion of a full-length Bos taurus LINE element is responsible for a transcriptional deregulation of the Normande Agouti genePIGMENT CELL & MELANOMA RESEARCH, Issue 4 2006Michael Girardot Summary Mammalian pigmentation is controlled by the concerted action of Tyr, Tyrp1 and Dct producing eumelanin and/or pheomelanin in melanocytes. The ratio of these two pigments is determined by the agonist , -melanocyte stimulating hormone and the antagonist Agouti protein acting on the Mc1r. Here we show that the Agouti gene is over-expressed in Normande breed compared with Prim'Holstein breed. The Normande cattle have a characteristic coat color phenotype with a variable presence of black (eumelanin) hair over a red/brown background. We have found a previously undescribed full-length L1-BT element inserted in the 5,-genomic sequence of the Agouti gene in Normande cattle which promotes the over-expression of alternative transcripts. The variable expression of the alternative transcript directed by the long interspersed nuclear element promoter may be the origin of the brindle coat color pattern of the Normande breed. This new bovine Agouti allele isolated in Normande breed has been named Abr. Finally, as ectopic over-expression of Agouti in Ay mice is responsible for the obesity syndrome, we discuss the possible consequences of Abr for meat and milk production in cattle. [source] Floral color patterns in a tropical orchid: Are they associated with reproductive success?PLANT SPECIES BIOLOGY, Issue 2 2007RAYMOND L. TREMBLAY Abstract We sought to measure phenotypic selection on petal color variation in populations of Lepanthes rupestris, a diminutive epilithic orchid of Puerto Rico that exhibits a polymorphism in petal color patterns (unicolor or bicolored). We censused seven populations monthly for 20 months and noted flower production and petal color pattern. Each flower was checked for pollinarium removal (male fitness measure) and fruit production (female fitness). In all populations, plants with bicolored petals dominated and comprised 63,82% of individuals. Aside from petal color differences, the two types were indistinguishable. Flower color pattern was generally not associated with either male or female reproductive success within or among populations or over time. Environmental conditions, rainfall and humidity, may account for both temporal and spatial variation in the reproductive success observed among sites. Although we were unable to tag fitness to petal color patterns, the consistent ratio of color morphs among populations suggests that factors other than just drift are responsible for the frequencies we observed. [source] Hardware-Based Volumetric Knit-WearCOMPUTER GRAPHICS FORUM, Issue 3 2002Katja Daubert We present a hardware-based, volumetric approach for rendering knit wear at very interactive rates. A single stitch is represented by a volumetric texture with each voxel storing the main direction of the strands of yarn inside it. We render the knit wear in layers using an approximation of the Banks model. Our hardware implementation allows specular and diffuse material properties to change from one voxel to the next. This enables us to represent yarn made up of different components or render garments with complicated color patterns. Furthermore, our approach can handle self-shadowing of the stitches, and can easily be adapted to also include view-independent scattering. The resulting shader lends itself naturally to mip-mapping, and requires no reordering of the base geometry, making it versatile and easy to use. Categories and Subject Descriptors (according to ACM CCS): I.3.3 [Computer Graphics]: Hardware Applications Volumetric Textures [source] THE EFFECTS OF GENOTYPE, AGE, AND SOCIAL ENVIRONMENT ON MALE ORNAMENTATION, MATING BEHAVIOR, AND ATTRACTIVENESSEVOLUTION, Issue 11 2005Lisa K. Miller Abstract The traits thought to advertise genetic quality are often highly susceptible to environmental variation and prone to change with age. These factors may either undermine or reinforce the potential for advertisement traits to signal quality depending on the magnitude of age-dependent expression, environmental variation, and genotype-age and genotype-environment interaction. Measurements of the magnitude of these effects are thus a necessary step toward assessing the implications of age dependence and environmental variability for the evolution of signals of quality. We conducted a longitudinal study of male guppies (Poecilia reticulata) from 22 full-sibling families. Each fish was assigned at maturity to one of three treatments in order to manipulate his allocation of resources to reproduction: a control in which the male was kept alone, a courtship-only treatment in which he could see and court a female across a clear partition, and a mating treatment in which he interacted freely with a female. We measured each male's size, ornamental color patterns, courtship, attractiveness to females, and mating success at three ages. Size was influenced by treatment and age-treatment interactions, indicating that courtship and mating may impose costs on growth. Tail size and color patterns were influenced by age but not by treatment, suggesting fixed age-dependent trajectories in these advertisement traits. By contrast, display rate and attempted sneak copulation rate differed among treatments but not among ages, suggesting greater plasticity of these behavioral traits. As a result of the different patterns of variation in ornamentation and behavior, male attractiveness and mating success responded to male age, treatment, and the interaction between age and treatment. Neither age nor treatment obscured the presence of genetic variation, and the genetic relationship between male ornamentation and attractiveness remained the same among treatments. Our findings suggest that neither age-dependent variation nor environmentally induced variation in reproductive effort is likely to undermine the reliability of male signaling. [source] EVOLUTION OF COLOR VARIATION IN DRAGON LIZARDS: QUANTITATIVE TESTS OF THE ROLE OF CRYPSIS AND LOCAL ADAPTATIONEVOLUTION, Issue 7 2004Devi M. Stuart-Fox Abstract Many animal species display striking color differences with respect to geographic location, sex, and body region. Traditional adaptive explanations for such complex patterns invoke an interaction between selection for conspicuous signals and natural selection for crypsis. Although there is now a substantial body of evidence supporting the role of sexual selection for signaling functions, quantitative studies of crypsis remain comparatively rare. Here, we combine objective measures of coloration with information on predator visual sensitivities to study the role of crypsis in the evolution of color variation in an Australian lizard species complex (Ctenophorus decresii). We apply a model that allows us to quantify crypsis in terms of the visual contrast of the lizards against their natural backgrounds, as perceived by potential avian predators. We then use these quantitative estimates of crypsis to answer the following questions. Are there significant differences in crypsis conspicuousness among populations? Are there significant differences in crypsis conspicuousness between the sexes? Are body regions "exposed" to visual predators more cryptic than "hidden" body regions? Is there evidence for local adaptation with respect to crypsis against different substrates? In general, our results confirmed that there are real differences in crypsis conspicuousness both between populations and between sexes; that exposed body regions were significantly more cryptic than hidden ones, particularly in females; and that females, but not males, are more cryptic against their own local background than against the background of other populations. Body regions that varied most in contrast between the sexes and between populations were also most conspicuous and are emphasized by males during social and sexual signaling. However, results varied with respect to the aspect of coloration studied. Results based on chromatic contrast ("hue' of color) provided better support for the crypsis hypothesis than did results based on achromatic contrast ("brightness' of color). Taken together, these results support the view that crypsis plays a substantial role in the evolution of color variation and that color patterns represent a balance between the need for conspicuousness for signaling and the need for crypsis to avoid predation. [source] A Combinatorial Approach for Colorimetric Differentiation of Organic Solvents Based on Conjugated Polymer-Embedded Electrospun FibersADVANCED FUNCTIONAL MATERIALS, Issue 2 2009Jaewon Yoon Abstract A combinatorial approach for the colorimetric differentiation of organic solvents is developed. A polydiacetylene (PDA)-embedded electrospun fiber mat, prepared with aminobutyric acid-derived diacetylene monomer PCDA-ABA 1, displays colorimetric stability when exposed to common organic solvents. In contrast, a fiber mat prepared with the aniline-derived diacetylene PCDA-AN 2 undergoes a solvent-sensitive color transition. Arrays of PDA-embedded microfibers are constructed by electrospinning poly(ethylene oxide) solutions containing various ratios of two diacetylene monomers. Unique color patterns are developed when the conjugated polymer-embedded electrospun fiber arrays are exposed to common organic solvents in a manner which enables direct colorimetric differentiation of the tested solvents. [source] Floral color patterns in a tropical orchid: Are they associated with reproductive success?PLANT SPECIES BIOLOGY, Issue 2 2007RAYMOND L. TREMBLAY Abstract We sought to measure phenotypic selection on petal color variation in populations of Lepanthes rupestris, a diminutive epilithic orchid of Puerto Rico that exhibits a polymorphism in petal color patterns (unicolor or bicolored). We censused seven populations monthly for 20 months and noted flower production and petal color pattern. Each flower was checked for pollinarium removal (male fitness measure) and fruit production (female fitness). In all populations, plants with bicolored petals dominated and comprised 63,82% of individuals. Aside from petal color differences, the two types were indistinguishable. Flower color pattern was generally not associated with either male or female reproductive success within or among populations or over time. Environmental conditions, rainfall and humidity, may account for both temporal and spatial variation in the reproductive success observed among sites. Although we were unable to tag fitness to petal color patterns, the consistent ratio of color morphs among populations suggests that factors other than just drift are responsible for the frequencies we observed. [source] Mining plant diversity: Gerbera as a model system for plant developmental and biosynthetic researchBIOESSAYS, Issue 7 2006Teemu H. Teeri Gerbera hybrida is a member of the large sunflower family (Asteraceae). Typical of Asteraceae, Gerbera bears different types of flowers in its inflorescence. The showy marginal flowers comprise elongate, ligulate corollas that are female, whereas the central and inconspicuous disc flowers are complete, with both male and female organs. As such, Gerbera offers great potential for comparative developmental research within a single genotype. Moreover, different Gerbera varieties show an impressive spectrum of color patterns, directly displaying responses to developmental cues at all important morphological levels (flower type, flower organ and within organs). Further, Gerbera harbors an arsenal of Asteraceae-type secondary metabolites, not present in other model plants. With powerful reverse genetics methods, a large collection of EST sequences and a new cDNA microarray, Gerbera has become a model plant of the sunflower family. BioEssays 28: 756,767, 2006. © 2006 Wiley Periodicals, Inc. [source] | ||||||||||