scholarly journals Sexually dimorphic dorsal coloration in a jumping spider: testing a potential case of sex-specific mimicry

2021 ◽  
Vol 8 (6) ◽  
pp. 210308
Author(s):  
Collette Cook ◽  
Erin C. Powell ◽  
Kevin J. McGraw ◽  
Lisa A. Taylor
Keyword(s):  
Colour Pattern ◽  
Sexually Dimorphic ◽  
Sham Control ◽  
Jumping Spider ◽  
Negative Results ◽  
Potential Case ◽  
Opposite Sex ◽  
Colour Patterns ◽  
Hymenopteran Insects ◽  
Predation Rates

To avoid predation, many animals mimic behaviours and/or coloration of dangerous prey. Here we examine potential sex-specific mimicry in the jumping spider Habronattus pyrrithrix . Previous work proposed that males' conspicuous dorsal coloration paired with characteristic leg-waving (i.e. false antennation) imperfectly mimics hymenopteran insects (e.g. wasps and bees), affording protection to males during mate-searching and courtship. By contrast, less active females are cryptic and display less leg-waving. Here we test the hypothesis that sexually dimorphic dorsal colour patterns in H. pyrrithrix are most effective when paired with sex-specific behaviours. We manipulated spider dorsal coloration with makeup to model the opposite sex and exposed them to a larger salticid predator ( Phidippus californicus ). We predicted that males painted like females should suffer higher predation rates than sham-control males. Likewise, females painted like males should suffer higher predation rates than sham-control females. Contrary to expectations, spiders with male-like coloration were attacked more than those with female-like coloration, regardless of their actual sex. Moreover, males were more likely to be captured, and were captured sooner, than females (regardless of colour pattern). With these unexpected negative results, we discuss alternative functional hypotheses for H. pyrrithrix colours, as well as the evolution of defensive coloration generally.

scholarly journals HIGH-RESOLUTION CHARACTERIZATION OF MALE ORNAMENTATION AND REEVALUATION OF SEX LINKAGE IN GUPPIES

2020 ◽  
Author(s):  
Jake Morris ◽  
Iulia Darolti ◽  
Wouter van der Bijl ◽  
Judith E. Mank
Keyword(s):  
High Resolution ◽  
Natural Populations ◽  
Colour Pattern ◽  
Sexually Dimorphic ◽  
Animal Colouration ◽  
In The Wild ◽  
Colour Changes ◽  
Colour Patterns ◽  
Male Ornaments

AbstractColouration plays a key role in the ecology of many species, influencing how an organism interacts with its environment, other species and conspecifics. Guppies are sexually dimorphic, with males displaying sexually selected colouration resulting from female preference. Previous work has suggested that much of guppy colour pattern variation is Y-linked. However, it remains unclear how many individual colour patterns are Y-linked in natural populations as much of the previous work has focused on phenotypes either not found in the wild, or aggregate measures such as total colour area. Moreover, ornaments have traditionally been identified and delineated by hand, and computational methods now make it possible to extract pixels and identify ornaments more automatedly, reducing the potential for human bias. Here we developed a pipeline for automated ornament identification and high-resolution image analysis of male guppy colour patterns and applied it to a multigenerational pedigree. Our results show that loci controlling the presence or absence of individual male ornaments in our population are not predominantly Y-linked. However, we find that ornaments of similar colour are not independent of each other, and modifier loci that affect whole animal colouration appear to be at least partially Y-linked. Considering these results, Y-linkage of individual ornaments may not be important in driving colour changes in natural populations of guppies, or in expansions of the non-recombining Y region, while Y-linked modifier loci that affect aggregate traits may well play an important role.

scholarly journals High-resolution characterization of male ornamentation and re-evaluation of sex linkage in guppies

2020 ◽  
Vol 287 (1937) ◽  
pp. 20201677
Author(s):  
Jake Morris ◽  
Iulia Darolti ◽  
Wouter van der Bijl ◽  
Judith E. Mank
Keyword(s):  
High Resolution ◽  
Natural Populations ◽  
Colour Pattern ◽  
Sexually Dimorphic ◽  
In The Wild ◽  
Colour Changes ◽  
Colour Patterns ◽  
Male Ornaments ◽  
Automated Methods

Coloration plays a key role in the ecology of many species, influencing how an organism interacts with its environment, other species and conspecifics. Guppies are sexually dimorphic, with males displaying sexually selected coloration resulting from female preference. Previous work has suggested that much of guppy colour pattern variation is Y-linked. However, it remains unclear how many individual colour patterns are Y-linked in natural populations as much of the previous work has focused on phenotypes either not found in the wild, or aggregate measures such as total colour area. Moreover, ornaments have traditionally been identified and delineated by hand, and computational methods now make it possible to extract pixels and identify ornaments with automated methods, reducing the potential for human bias. Here we developed a pipeline for semi-automated ornament identification and high-resolution image analysis of male guppy colour patterns and applied it to a multigenerational pedigree. Our results show that loci controlling the presence or the absence of individual male ornaments in our population are not predominantly Y-linked. However, we find that ornaments of similar colour are not independent of each other, and modifier loci that affect whole animal coloration appear to be at least partially Y-linked. Considering these results, Y-linkage of individual ornaments may not be important in driving colour changes in natural populations of guppies, or in expansions of the non-recombining Y region, while Y-linked modifier loci that affect aggregate traits may well play an important role.

scholarly journals Dog colour patterns explained by modular promoters of ancient canid origin

2021 ◽  
Author(s):  
Danika L. Bannasch ◽  
Christopher B. Kaelin ◽  
Anna Letko ◽  
Robert Loechel ◽  
Petra Hug ◽  
...  
Keyword(s):  
Colour Pattern ◽  
Hair Cycle ◽  
Temporal And Spatial Distribution ◽  
Multiple Alleles ◽  
Haplotype Combination ◽  
Regulatory Modules ◽  
Regulatory Module ◽  
Temporal And Spatial ◽  
Selection For ◽  
Colour Patterns

AbstractDistinctive colour patterns in dogs are an integral component of canine diversity. Colour pattern differences are thought to have arisen from mutation and artificial selection during and after domestication from wolves but important gaps remain in understanding how these patterns evolved and are genetically controlled. In other mammals, variation at the ASIP gene controls both the temporal and spatial distribution of yellow and black pigments. Here, we identify independent regulatory modules for ventral and hair cycle ASIP expression, and we characterize their action and evolutionary origin. Structural variants define multiple alleles for each regulatory module and are combined in different ways to explain five distinctive dog colour patterns. Phylogenetic analysis reveals that the haplotype combination for one of these patterns is shared with Arctic white wolves and that its hair cycle-specific module probably originated from an extinct canid that diverged from grey wolves more than 2 million years ago. Natural selection for a lighter coat during the Pleistocene provided the genetic framework for widespread colour variation in dogs and wolves.

Molecular phylogeny of Clibanarius Dana, 1852 from the Indo-West Pacific: evolution of pereopod colour pattern and habitat adaptation

Crustaceana ◽  
2019 ◽  
Vol 92 (7) ◽  
pp. 799-839 ◽  
Author(s):  
Akihiro Yoshikawa ◽  
Kazuho Ikeo ◽  
Junichi Imoto ◽  
Wachirah Jaingam ◽  
Lily Surayya Eka Putri ◽  
...  
Keyword(s):  
Histone H3 ◽  
Hermit Crabs ◽  
Colour Pattern ◽  
12S Rrna ◽  
Habitat Adaptation ◽  
Soft Sediments ◽  
Mitochondrial 12S Rrna ◽  
Nuclear Histone ◽  
Colour Patterns ◽  
Hard Substrates

Abstract Species of hermit crabs in the genus Clibanarius Dana, 1852 have adapted to various environments in the intertidal areas, including hard substrates and soft sediments. These species often bear a close morphological resemblance to each other, therefore, the colouration on the pereopods can be one of the reliable characteristics to distinguish the species. However, the evolutionary relationships among species with different colour patterns and relationships between colour patterns and habitat adaptation have not previously been investigated. Therefore, we reconstructed the phylogenetic relationships among 19 species of Clibanarius based on mitochondrial [12S rRNA, 16S rRNA and cytochrome oxidase I] and nuclear [histone H3] DNA markers. The results suggest that the striped and solid colour elements have evolved multiple times independently, with the ancestral colour pattern potentially being scattered, bright colour spots with a bright colour band. Our findings also suggest that evolutionary adaptation from hard substrates to mudflats and soft sediments may have occurred at least twice.

scholarly journals Scrapie-resistant sheep show certain coat colour characteristics

2009 ◽  
Vol 91 (1) ◽  
pp. 39-46 ◽  
Author(s):  
R. M. SAWALHA ◽  
L. BELL ◽  
S. BROTHERSTONE ◽  
I. WHITE ◽  
A. J. WILSON ◽  
...  
Keyword(s):  
Maximum Likelihood ◽  
Linear Model ◽  
Morphological Diversity ◽  
Coat Colour ◽  
Unintended Consequences ◽  
Colour Pattern ◽  
Reverse Pattern ◽  
Colour Patterns ◽  
Log Linear ◽  
The Relationship

SummarySusceptibility to scrapie is known to be associated with polymorphisms at the prion protein (PrP) gene, and this association is the basis of current selective programmes implemented to control scrapie in many countries. However, these programmes might have unintended consequences for other traits that might be associated withPrPgenotype. The objective of this study was to investigate the relationship betweenPrPgenotype and coat colour characteristics in two UK native sheep breeds valued for their distinctive coat colour patterns. Coat colour pattern, darkness and spotting andPrPgenotype records were available for 11 674 Badgerfaced Welsh Mountain and 2338 Shetland sheep. The data were analysed with a log–linear model using maximum likelihood. Results showed a strong significant association ofPrPgenotype with coat colour pattern in Badgerfaced Welsh Mountain and Shetland sheep and with the presence of white spotting in Shetland sheep. Animals with the ARR/ARR genotype (the most scrapie resistant) had higher odds of having a light dorsum and a dark abdomen than the reverse pattern. The implication of these associations is that selection to increase resistance to scrapie based only onPrPgenotype could result in change in morphological diversity and affect other associated traits such as fitness.

Cautery-induced colour patterns in Precis coenia (Lepidoptera: Nymphalidae)

Development ◽  
1985 ◽  
Vol 86 (1) ◽  
pp. 191-203
Author(s):  
H. F. Nijhout
Keyword(s):  
Computer Simulations ◽  
Hind Wing ◽  
Wing Surface ◽  
Colour Pattern ◽  
Physiological Conditions ◽  
Classical Work ◽  
Pattern Determination ◽  
Colour Patterns ◽  
Experimental Findings ◽  
Precis Coenia

Cautery of the dorsal hind wing in the butterfly, Precis coenia, induces the formation of a concentric colour pattern around the site of injury. The induced pattern is identical in pigmentation to the eyespots that normally develop on this wing surface. This response to cautery also occurs, though much less dramatically, on the ventral forewing. In addition to the peculiar response to cautery, the dorsal hindwing of Precis also develops a series of unique pattern aberrations in response to coldshock. These consist of irregular elongation of the anterior eyespot along the proximodistal axis of the wing. In the most dramatic aberrations the eyespot field covers the entire anterior half of the wing surface. An analysis is presented that attempts to reconcile the effects of cautery on the Precis hindwing with the very different morphological effects of cautery on the colour pattern of Ephestia kühniella, described by Kühn & Von Engelhardt. Computer simulations reveal that the finding presented in this paper, as well as the classical work on Ephestia, can both be explained by assuming that the site of cautery becomes a sink for one of the morphogens involved in colour pattern determination. The experimental findings furthermore indicate that minor perturbations of the wing epidermis can evoke the physiological conditions that attend normal eyespot determination. It is shown that this interpretation also helps to explain the unusual pattern modifications following coldshock.

Cross-sexual Transfer

2003 ◽  
Author(s):  
Mary Jane West-Eberhard
Keyword(s):  
Sex Determination ◽  
Sexually Dimorphic ◽  
Male And Female ◽  
Alternative Phenotypes ◽  
Opposite Sex ◽  
Critical Age ◽  
Sexual Traits ◽  
Discrete Traits ◽  
Dimorphic Species ◽  
Determination Mechanism

Distinctive male and female traits are perhaps the most familiar of all divergent specializations within species. In cross-sexual transfer, discrete traits that are expressed exclusively in one sex in an ancestral species appear in the opposite sex of descendants. An example is the expression of brood care by males in a lineage where ancestral females are the exclusive caretakers of the young, as in some voles (Thomas and Birney, 1979). Despite the prominence of sexual dimorphism and sex reversals in nature, and an early explicit treatment by Darwin, discussed in the next section, cross-sexual transfer is not often recognized as a major factor in the evolution of novelty (but see, on animals, Mayr, 1963, pp. 435-439; Mayr, 1970, p. 254; on plants, Iltis, 1983). When more widely investigated, cross-sexual transfer may prove to rival heterochrony and duplication as an important source of novelties in sexually dimorphic lineages. For this reason, I devote more attention here to cross-sexual transfer than to these other, well-established general patterns of change. The male and female of a sexually dimorphic species may be so different that it is easy to forget that each individual carries most or all of the genes necessary to produce the phenotype of the opposite sex. Sex determination, like caste determination and other switches between alternative phenotypes, depends on only a few genetic loci or, in many species, environmental factors (Bull, 1983). There is considerable flexibility in sex determination and facultative reversal in some taxa. Among fish, for example, there is even a species wherein sex is determined by juvenile size at a critical age (Francis and Barlow, 1993). The sex determination mechanism, whatever its nature, leads to a series of sex-limited responses, often coordinated by hormones and not necessarily all occurring at once. A distinguishing aspect of sexually dimorphic traits in adults is that there is often a close homology between the secondary sexual traits that are differently modified in the two sexes.

The immature stages of the genus Trepobates Uhler (Hemiptera: Heteroptera: Gerridae), with an identification key to instars and the description of the nymphs of T. taylori (Kirkaldy)

Zootaxa ◽  
2011 ◽  
Vol 2733 (1) ◽  
pp. 1 ◽  
Author(s):  
SUSANA AMANDA KONOPKO ◽  
SILVIA ANA MAZZUCCONI
Keyword(s):  
Antennal Segment ◽  
Identification Key ◽  
Colour Pattern ◽  
Immature Stages ◽  
Viii And Ix ◽  
Colour Patterns ◽  
First Time

The egg and five instars of Trepobates are described based on examined material of T. taylori and published information of T. inermis, T. knighti, T. panamensis, T. pictus, T. subnitidus and T. trepidus. The characters most useful in identifying nymphs I– V of Trepobates are: the width of the head; the lengths of the antennae, femora 1–3, tibiae 2–3 and tarsus 2–3; the Y-shaped ecdysial line of the head; the colour patterns of the proand mesonotum; and the urosternites VIII and IX. A key to the five nymphal instars of Trepobates is provided. The five instars of T. taylori are described and illustrated for the first time, with emphasis on the morphometry and colour pattern of selected structures, and chaetotaxy of the antennae; the egg is figured and redescribed. The characters useful in identifying nymphs I–V of this species are: the colour pattern of the head; the chaetotaxy of the antennal segment I; the lengths of the antennal segment III and mesonotum; and the width of the pronotum. Differences between sexes in nymphs IV and V are presented.

scholarly journals Phenotypic variation in Heliconius erato crosses shows that iridescent structural colour is sex-linked and controlled by multiple genes

2018 ◽  
Vol 9 (1) ◽  
pp. 20180047 ◽  
Author(s):  
Melanie N. Brien ◽  
Juan Enciso-Romero ◽  
Andrew J. Parnell ◽  
Patricio A. Salazar ◽  
Carlos Morochz ◽  
...  
Keyword(s):  
Phenotypic Variation ◽  
Genetic Basis ◽  
Sex Chromosome ◽  
Scattering Data ◽  
Colour Pattern ◽  
Structural Colour ◽  
X Ray Scattering ◽  
Multiple Genes ◽  
Colour Patterns ◽  
Blue Reflectance

Bright, highly reflective iridescent colours can be seen across nature and are produced by the scattering of light from nanostructures. Heliconius butterflies have been widely studied for their diversity and mimicry of wing colour patterns. Despite iridescence evolving multiple times in this genus, little is known about the genetic basis of the colour and the development of the structures which produce it. Heliconius erato can be found across Central and South America, but only races found in western Ecuador and Colombia have developed blue iridescent colour. Here, we use crosses between iridescent and non-iridescent races of H. erato to study phenotypic variation in the resulting F 2 generation. Using measurements of blue colour from photographs, we find that iridescent structural colour is a quantitative trait controlled by multiple genes, with strong evidence for loci on the Z sex chromosome. Iridescence is not linked to the Mendelian colour pattern locus that also segregates in these crosses (controlled by the gene cortex ). Small-angle X-ray scattering data show that spacing between longitudinal ridges on the scales, which affects the intensity of the blue reflectance, also varies quantitatively in F 2 crosses.

scholarly journals Evolutionary fine-tuning of background-matching camouflage among geographical populations in the sandy beach tiger beetle

2020 ◽  
Vol 287 (1941) ◽  
pp. 20202315
Author(s):  
Nayuta Yamamoto ◽  
Teiji Sota
Keyword(s):  
Sequence Data ◽  
Evolutionary Process ◽  
Fine Tuning ◽  
Colour Pattern ◽  
Tiger Beetle ◽  
Background Matching ◽  
Geographical Populations ◽  
Geographical Distances ◽  
The Japanese Archipelago ◽  
Colour Patterns

Background-matching camouflage is a widespread adaptation in animals; however, few studies have thoroughly examined its evolutionary process and consequences. The tiger beetle Chaetodera laetescripta exhibits pronounced variation in elytral colour pattern among sandy habitats of different colour in the Japanese Archipelago. In this study, we performed digital image analysis with avian vision modelling to demonstrate that elytral luminance, which is attributed to proportions of elytral colour components, is fine-tuned to match local backgrounds. Field predation experiments with model beetles showed that better luminance matching resulted in a lower attack rate and corresponding lower mortality. Using restriction site-associated DNA (RAD) sequence data, we analysed the dispersal and evolution of colour pattern across geographical locations. We found that sand colour matching occurred irrespective of genetic and geographical distances between populations, suggesting that locally adapted colour patterns evolved after the colonization of these habitats. Given that beetle elytral colour patterns presumably have a quantitative genetic basis, our findings demonstrate that fine-tuning of background-matching camouflage to local habitat conditions can be attained through selection by visual predators, as predicted by the earliest proponent of natural selection.

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