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Summary: Detecting homologous sequences in organisms is an essential step in protein structure and function prediction, gene annotation and phylogenetic tree construction. Heuristic methods are often employed for quality control of putative homology clusters. These heuristics, however, usually only apply to pairwise sequence comparison and do not examine clusters as a whole. We present the Orthology Group Cleaner (the OGCleaner), a tool designed for filtering putative orthology groups as homology or non-homology clusters by considering all sequences in a cluster. The OGCleaner relies on high-quality orthologous groups identified in OrthoDB to train machine learning algorithms that are able to distinguish between true-positive and false-positive homology groups. This package aims to improve the quality of phylogenetic tree construction especially in instances of lower-quality transcriptome assemblies. [ABSTRACT FROM AUTHOR]

The article focuses on a study aimed at analyzing the increasing use of molecular data over morphological data in phylogenetic studies. It mentions the procedure followed and journals reviewed during the study, and discusses its findings on the increase in number of molecular studies during the period of investigation. It also suggests the need to preserve knowledge on morphological variation for phylogenetic studies, and suggests further research on the data used in entomological research.

• A set of anchor hybridization probes are developed for all lineages of Odonata. • Phylogenetic reconstruction of all but two major odonate lineages. • An improved phylogenetic backbone of Odonata is provided. • Five new families are proposed and two more reinstated. • An updated classification scheme for Odonata is provided. Dragonflies and damselflies are a charismatic, medium-sized insect order (~6300 species) with a unique potential to approach comparative research questions. Their taxonomy and many ecological traits for a large fraction of extant species are relatively well understood. However, until now, the lack of a large-scale phylogeny based on high throughput data with the potential to connect both perspectives has precluded comparative evolutionary questions for these insects. Here, we provide an ordinal hypothesis of classification based on anchored hybrid enrichment using a total of 136 species representing 46 of the 48 families or incertae sedis , and a total of 478 target loci. Our analyses recovered the monophyly for all three suborders: Anisoptera, Anisozygoptera and Zygoptera. Although the backbone of the topology was reinforced and showed the highest support values to date, our genomic data was unable to stronglyresolve portions of the topology. In addition, a quartet sampling approach highlights the potential evolutionary scenarios that may have shaped evolutionary phylogeny (e.g., incomplete lineage sorting and introgression) of this taxon. Finally, in light of our phylogenomic reconstruction and previous morphological and molecular information we proposed an updated odonate classification and define five new families (Amanipodagrionidae fam. nov., Mesagrionidae fam. nov., Mesopodagrionidae fam. nov., Priscagrionidae fam. nov., Protolestidae fam. nov.) and reinstate another two (Rhipidolestidae stat. res., Tatocnemididae stat. res.). Additionally, we feature the problematic taxonomic groupings for examination in future studies to improve our current phylogenetic hypothesis. [ABSTRACT FROM AUTHOR]

Vanuatubasis Ober & Staniczek, 2009 is an endemic genus of damselfly found on the island archipelago of Vanuatu. Previously only three species were assigned to the genus. Here, all known species of Vanuatubasis are formally described and treated, including the association of females for known species. The following new congeners are also described: V. discontinua sp. nov., V. evelynae sp. nov., V. insularivorum sp. nov., V. kapularum sp. nov., V. nunggoli sp. nov., V. rhomboides sp. nov., and V. xanthochroa sp. nov. from material collected across six different islands. An illustrated key to both males and females of all species within Vanuatubasis is provided as well as distributions for all known species. [ABSTRACT FROM AUTHOR]

Temporal ecological niche partitioning is an underappreciated driver of speciation. While insects have long been models for circadian biology, the genes and circuits that allow adaptive changes in diel-niches remain poorly understood. We compared gene expression in closely related day- and night-active non-model wild silk moths, with otherwise similar ecologies. Using an ortholog-based pipeline to compare RNA-Seq patterns across two moth species, we find over 25 pairs of gene orthologs showing differential expression. Notably, the gene disco, involved in circadian control, optic lobe and clock neuron development in Drosophila, shows robust adult circadian mRNA cycling in moth heads. Disco is highly conserved in moths and has additional zinc-finger domains with specific nocturnal and diurnal mutations. We propose disco as a candidate gene for the diversification of temporal diel-niche in moths. [ABSTRACT FROM AUTHOR]

The coastal areas of Vanuatu are under a multitude of threats stemming from commercialization, human development, and climate change. Atyphella Olliff is a genus of firefly that includes species endemic to these coastal areas and will need protection. The research that has already been conducted was affected by accessibility due to the remote nature of the islands which left numerous knowledge gaps caused by a lack of distributional data (e.g., Wallacean shortfall). Species distribution models (SDM) are a powerful tool that allow for the modeling of the broader distribution of a taxon, even with limited distributional data available. SDMs assist in filling the knowledge gap by predicting potential areas that could contain the species of interest, making targeted collecting and conservation efforts more feasible when time, resources, and accessibility are major limiting factors. Here a MaxEnt prediction was used to direct field collecting and we now provide an updated predictive distribution for this endemic firefly genus. The original model was validated with additional fieldwork, ultimately expanding the known range with additional locations first identified using MaxEnt. A bias analysis was also conducted, providing insight into the effect that developments such as roads and settlements have on collecting and therefore the SDM, ultimately allowing for a more critical assessment of the overall model. After demonstrating the accuracy of the original model, this new updated SDM can be used to identify specific areas that will need to be the target of future conservation efforts by local government officials. [ABSTRACT FROM AUTHOR]

Background: Acceptance of evolutionary theory varies widely and is often associated with religious background. Some have suggested there exists an additional relationship between scientific reasoning ability and the acceptance of evolutionary theory. In this study, we used structural equation modeling to test whether scientific reasoning ability predicts religiosity, acceptance of creationist views, or acceptance of evolution. We administered internet-based surveys to 724 individuals nationwide who self-describe as being religious and built a structural-equation model to test predictive abilities.Results: We found that while religiosity positively predicts the acceptance of creationist views and negatively predicts the acceptance of evolution, scientific reasoning ability does not predict religiosity, acceptance of creationist views, or acceptance of evolutionary theory.Conclusions: With a lack of any relationship between scientific reasoning ability and acceptance, an approach to evolution education that focuses on appealing to scientific reasoning may prove fruitless in changing student attitudes toward evolution; alternative teaching approaches regarding evolution are warranted. [ABSTRACT FROM AUTHOR]

Opsins, combined with a chromophore, are the primary light-sensing molecules in animals and are crucial for color vision. Throughout animal evolution, duplications and losses of opsin proteins are common, but it is unclear what is driving these gains and losses. Light availability is implicated, and dim environments are often associated with low opsin diversity and loss. Correlations between high opsin diversity and bright environments, however, are tenuous. To test if increased light availability is associated with opsin diversification, we examined diel niche and identified opsins using transcriptomes and genomes of 175 butterflies and moths (Lepidoptera). We found 14 independent opsin duplications associated with bright environments. Estimating their rates of evolution revealed that opsins from diurnal taxa evolve faster—at least 13 amino acids were identified with higher dN/dS rates, with a subset close enough to the chromophore to tune the opsin. These results demonstrate that high light availability increases opsin diversity and evolution rate in Lepidoptera. Yash Sondhi et al. annotate the genomes and transcriptomes of 175 Lepidoptera species and identify 14 independent opsin duplications associated with bright environments. From estimating their rates of evolution, the authors reveal that opsins from diurnal taxa evolve faster, and that high light availability increases opsin diversity and evolution rate in this order. [ABSTRACT FROM AUTHOR]

[Display omitted] • The Vitiaz arc likely played an important role in the divergence of damselfly genera. • The origin of Vanuatubasis is likely due to a vicariance event. • The island of Espiritu Santo acted as an important source for dispersal events in Vanuatu. • Biogeographical reconstructions are limited by extinct lineages and areas. South Pacific islands provide an ideal study system to explore patterns of speciation, specifically examining the role of dispersal versus vicariance. Dispersal is often the suggested mechanism of diversification in the South Pacific, specifically among remote island chains. Here, we provide a phylogeny of several related genera of Coenagrionidae (Odonata: Zygoptera) from the South Pacific, based on five molecular loci, in order to examine patterns of speciation in the region. We used the endemic damselfly genera Nesobasis, Nikoulabasis, and Vanuatubasis found across both Fiji and Vanuatu. Knowledge of the geologic history of the region was used to inform our understanding of the evolution of these genera. Both archipelagos used to be part of the Vitiaz arc which spanned from the Solomon Islands to Tonga and began to break apart 10–12 Ma. Results of our divergence-time estimations and biogeographic reconstructions support that the breakup of this arc acted as a significant vicariance event in the evolution of these taxa. Specifically, it led to the extant generic diversity seen in these damselflies. We find that within the archipelago of Vanuatu, that Espiritu Santo served as an important source for dispersal to other islands with Malekula acting as a stepping stone to Efate. [ABSTRACT FROM AUTHOR]

Island archipelagos in the South Pacific have relatively high species endemism within the insect order Odonata, specifically damselflies. Nesobasis Selys, 1891, an endemic damselfly genus from Fiji, includes over 20 species, but a clear understanding of its evolutionary relationship to other damselflies in the region is lacking. Scientists have questioned the monophyly of Nesobasis due to variations within the genus leading to the establishment of three divisions provisionally named as: comosa-, erythrops- and longistyla- groups. However, Nesobasis has shown to be monophyletic in previous phylogenetic analyses. Using additional species in this study, we investigate the phylogenetic relationships between Nesobasis and other damselflies from the region, specifically the endemic Vanuatubasis Ober & Staniczek, 2009 from the neighboring island archipelagos of Vanuatu. The relationship between these taxa has not yet been examined with molecular data. Five genes were used in a maximum likelihood phylogenetic reconstruction and examined morphological data to determine the relationship between these genera. Our results recover three distinct clades overall with Vanuatubasis nested within Nesobasis (i.e., non-monophyletic). Vanuatubasis is sister to the longistyla and erythrops groups. The third group, comosa , was found sister to the clade of Vanuatubasis (longistyla + erythrops). As a result of these findings, we propose the new genus, Nikoulabasis gen. nov. [ABSTRACT FROM AUTHOR]

Dermaptera is a relatively small order of free-living insects that typically feed on detritus and other plant material. However, two earwig lineages – Arixeniidae and Hemimeridae – are epizoic on Cheiromeles bats and Beamys and Cricetomys rats respectively. Both of these epizoic families are comprised of viviparous species. The monophyly of these epizoic lineages and their placement within dermapteran phylogeny has remained unclear. A phylogenetic analyses was performed on a diverse sample of 47 earwig taxa for five loci (18S rDNA, 28S rDNA, COI, Histone 3, and Tubulin Alpha I). Our results support two independent origins of the epizoic lifestyle within Dermaptera, with Hemimeridae and Arixeniidae each derived from a different lineage of Spongiphoridae. Our analyses places Marava , a genus of spongiphorids that includes free-living but viviparous earwigs, as sister group to Arixeniidae, suggesting that viviparity evolved prior to the shift to the epizoic lifestyle. Additionally, our results support the monophyly of Forficulidae and Chelisochidae and the paraphyly of Labiduridae, Pygidicranidae, Spongiphoridae, and Anisolabididae. [ABSTRACT FROM AUTHOR]

Acceptance of human evolution seems to be the majority position for the U.S. population; however, acceptance of evolution among conservative Christian groups is low, sometimes below 50%. There are many different reasons for this low acceptance, leading to a significant disconnect between scientific specialists and the general population. This study examined students in an introductory biology class at a large public university. Semistructured in-person interviews were conducted to better understand students’ belief in evolution, or their lack thereof. At the beginning of the semester, 19 of the participants accepted evolution, a number that increased to 29 students by the end of the semester. In contrast, only eight students accepted human evolution at the beginning of the semester, but the number increased to 21 students by the semester’s end. The interviews elucidated three essential factors that can change students’ minds: teaching the evidence of evolution, providing the influence of a role model to reconcile religion and science, and assisting students with overcoming misconceptions about evolution. [ABSTRACT FROM AUTHOR]

[Display omitted] • Petaluridae is a relict dragonfly family, comprised of only eleven species known for their exclusive use of fen and bog habitats, burrowing behavior as nymphs, remarkably large adult body sizes, and extended lifespans. • Utilizing a dataset of over 900 loci, we reconstructed a maximum likelihood phylogeny to understand the evolutionary history of Petaluridae. We further examined intrafamilial relationships at "difficult nodes" through gene tree likelihoods and quartet scores. • Through divergence time estimation analysis, we trace the origin of the Petaluridae back to the early Cretaceous. The family comprises a Gondwanan and a Laurasian clade, which separated approximately 160 million years ago. Species within Petaluridae exhibit a wide range of ages, from 6 to 120 million years. • Our biogeographical analysis suggest that continental drift, land bridge exposure, and the uplift of mountain ranges played important roles in the divergence of Petaluridae. Despite their strategy of habitat specialization, Petaluridae species have persisted for tens of millions of years, an exception to the notion that specialization leads to extinction over long time scales. Petaluridae (Odonata: Anisoptera) is a relict dragonfly family, having diverged from its sister family in the Jurassic, of eleven species that are notable among odonates (dragonflies and damselflies) for their exclusive use of fen and bog habitats, their burrowing behavior as nymphs, large body size as adults, and extended lifespans. To date, several nodes within this family remain unresolved, limiting the study of the evolution of this peculiar family. Using an anchored hybrid enrichment dataset of over 900 loci we reconstructed the species tree of Petaluridae. To estimate the temporal origin of the genera within this family, we used a set of well-vetted fossils and a relaxed molecular clock model in a divergence time estimation analysis. We estimate that Petaluridae originated in the early Cretaceous and confirm the existence of monophyletic Gondwanan and Laurasian clades within the family. Our relaxed molecular clock analysis estimated that these clades diverged from their MRCA approximately 160 mya. Extant lineages within this family were identified to have persisted from 6 (Uropetala) to 120 million years (Phenes). Our biogeographical analyses focusing on a set of key regions suggest that divergence within Petaluridae is largely correlated with continental drift, the exposure of land bridges, and the development of mountain ranges. Our results support the hypothesis that species within Petaluridae have persisted for tens of millions of years, with little fossil evidence to suggest widespread extinction in the family, despite optimal conditions for the fossilization of nymphs. Petaluridae appear to be a rare example of habitat specialists that have persisted for tens of millions of years. [ABSTRACT FROM AUTHOR]

We understand very little about the timing and origins of bioluminescence, particularly as a predator avoidance strategy. Understanding the timing of its origins, however, can help elucidate the evolution of this ecologically important signal. Using fireflies, a prevalent bioluminescent group where bioluminescence primarily functions as aposematic and sexual signals, we explore the origins of this signal in the context of their potential predators. Divergence time estimations were performed using genomic-scale datasets providing a robust estimate for the origin of firefly bioluminescence as both a terrestrial and as an aerial signal. Our results recover the origin of terrestrial beetle bioluminescence at 141.17 (122.63–161.17) Ma and firefly aerial bioluminescence at 133.18 (117.86–152.47) Ma using a large dataset focused on Lampyridae; and terrestrial bioluminescence at 148.03 (130.12–166.80) Ma, with the age of aerial bioluminescence at 104.97 (99.00–120.90) Ma using a complementary Elateroidea dataset. These ages pre-date the origins of all known extant aerial predators (i.e. bats and birds) and support much older terrestrial predators (assassin bugs, frogs, ground beetles, lizards, snakes, hunting spiders and harvestmen) as the drivers of terrestrial bioluminescence in beetles. These ages also support the hypothesis that sexual signalling was probably the original function of this signal in aerial fireflies. [ABSTRACT FROM AUTHOR]

Oxygen is an important and often limiting reagent of a firefly's bioluminescent chemical reaction. Therefore, the development of the tracheal system and its subsequent modification to support the function of firefly light organs are key to understanding this process. We employ micro-CT scanning, 3D rendering, and confocal microscopy to assess the abdominal tracheal system in Photinus pyralis from the external spiracles to the light organ's internal tracheal brush, a feature named here for the first time. The abdominal spiracles in firefly larvae and pupae are of the biforous type, with a filter apparatus and appear to have an occlusor muscle to restrict airflow. The first abdominal spiracle in the adult firefly is enlarged and bears an occlusor muscle, and abdominal spiracles two through eight are small, with a small atrium and bilobed closing apparatus. Internal tracheal system features, including various branches, trunks, and viscerals, were homologized across life stages. In adults, the sexually dimorphic elaboration and increase in volume associated with tracheal features of luminous segments emphasizes the importance of gas exchange during the bioluminescent process. [ABSTRACT FROM AUTHOR]

The genus Anax is a group of cosmopolitan dragonflies noted for its conspicuous migratory behaviours and large size. Here we present the first dated, species-level, multigene, molecular phylogeny for the group to test generic and species-limits, as well as the evolution of migration and range size. Using five mitochondrial and nuclear gene regions (COI , COI/COII , CYTB/ND1 , ITS1 and PRMT) from 20 species, we reconstructed a phylogeny of Anax using both a Bayesian and maximum likelihood approach. We found that Anax (including its hypothesized sister group Hemianax) forms a monophyletic group, and that 12 out of 20 species tested positive for monophyly were also monophyletic. The monophyly of several species of Anax is less clear. Migratory behaviour, which is known to occur in at least nine species, is recovered as the ancestral behaviour, which was lost and subsequently gained at least three times. Geographic range size seems to be tightly associated with migratory behaviour. [ABSTRACT FROM AUTHOR]

The leg regeneration capabilities of damselflies are understudied. Here we present the first data of regenerated limbs across a genus of damselfly based on adult specimens collected in the field to illustrate the prevalence of limb loss among nymphs. We show that this phenomenon is much more prevalent than previously thought, as 42 percent of individuals were found with regenerated limbs. Furthermore, we test for patterns within these data to begin to unravel the potential causes of limb loss in nymphal damselflies, showing that intrinsic factors such as sex and species cannot explain the patterns of limb loss pointing to environmental factors as the probable cause. We argue that Odonata limb regeneration provides a potentially unique perspective into the nymphal stage of these organisms. • Odonates exhibit effective leg regeneration abilities that result in a fully functional limb. • Prevalence of leg regeneration in Vanuatubasis is reported as much higher than previously understood. • Sex and species do not explain the extent of regeneration suggesting environmental factors may play a larger role. [ABSTRACT FROM AUTHOR]

Among the greatest hindrances to the acceptance of evolution are religious factors. In this study, we take a more rigorous and detailed approach to the specific effects of religious affiliation and self-reported religiosity on the acceptance of creationist viewpoints and the overall acceptance of evolution. Over 700 religious adults who claimed affiliation with one of four broad religious groups (Southern Baptist, Catholic, Jewish, and The Church of Jesus Christ of Latter-day Saints) were surveyed nationwide using a newly validated instrument. Using structural equation modeling and variable association analysis, we demonstrate that, although creationism and evolution acceptance are negatively correlated, the relationships differ with respect to religious affiliation and with respect to religiosity. These data provide compelling evidence that evolution is viewed differently on the basis of both religious affiliation and religiosity, and they lead to important educational implications when approaching religious students on the subject of evolution. [ABSTRACT FROM AUTHOR]

Fireflies are some of the most captivating organisms on the planet. They have a rich history as subjects of scientific study, especially in relation to their bioluminescent behavior. Yet, the phylogenetic relationships of fireflies are still poorly understood. Here, we present the first total evidence approach to reconstruct lampyrid phylogeny using both a molecular matrix from six loci and an extensive morphological matrix. Using this phylogeny we test the hypothesis that adult bioluminescence evolved after the origin of the firefly clade. The ancestral state of adult bioluminescence is recovered as non-bioluminescent with one to six gains and five to ten subsequent losses. The monophyly of the family, as well as the subfamilies is also tested. Ototretinae, Cyphonocerinae, Luciolinae (incl. Pristolycus ), Amydetinae, “ cheguevarinae ” sensu Jeng 2008, and Photurinae are highly supported as monophyletic. With the exception of four taxa, Lampyrinae is also recovered as monophyletic with high support. Based on phylogenetic and morphological data Lamprohiza , Phausis , and Lamprigera are transferred to Lampyridae incertae sedis. [ABSTRACT FROM AUTHOR]

The tribe Plesioclytini was recently erected for a single genus of cerambycine longhorn beetle. The group was diagnosed from a proposed sister lineage, the diverse Clytini; however, a formal phylogenetic analysis was not performed due to limitations in data availability. Here, we present a phylogenetic reconstruction from five loci, that Plesioclytini is not sister to Clytini, but is instead only distantly related. Subsequent morphological investigations provide additional support for this placement. [ABSTRACT FROM AUTHOR]

Polarization is a property of light that describes the oscillation of the electric field vector. Polarized light can be detected by many invertebrate animals, and this visual channel is widely used in nature. Insects rely on light polarization for various purposes, such as water detection, improving contrast, breaking camouflage, navigation, and signaling during mating. Dragonflies and damselflies (Odonata) are highly visual insects with polarization sensitivity for water detection and likely also navigation. Thus, odonates can serve as ideal models for investigating the ecology and evolution of polarized light perception. We provide an overview of the current state of knowledge concerning polarized light sensitivity in these insects. Specifically, we review recent findings related to the ecological, morphological, and physiological causes that enable these insects to perceive polarized light and discuss the optical properties responsible for the reflection of polarized light by their bodies and wings. Finally, we identify gaps in the current research and suggest future directions that can help to further advance our knowledge of polarization sensitivity in odonates., Competing Interests: Declarations. Conflict of interest: The authors declare no competing interests., (© 2025. The Author(s).)

Gondwanan elaterids, previously thought to be unrelated, include bioluminescent Campyloxenus earlier placed in bioluminescent Pyrophorinae. Genomic data suggest close relationships between Gondwanan groups. We maintain Morostomatinae and Hapatesinae and redefine Pityobiinae with Nearctic Pityobiini, Gondwanan Parablacini stat. nov ., Campyloxenini stat. nov. , and Tibionemini trib. nov. Their ancestors putatively underwent differentiation in Gondwana during the Cretaceous separation of southern continents. In contrast with their age, extant groups are species poor. Campyloxenus represents a recent origin of bioluminescence, no older than ∼53 my. Its large pronotal lanterns differ from Pyrophorini and resemble color patches of sympatric beetle co-mimics. This discovery highlights the fourth or fifth origin of bioluminescence in Elateroidea, alongside the lampyroid clade, click beetles Pyrophorini, Alampoides and Coctilelater in Anaissini (Pyrophorinae), and Balgus schnusei (Thylacosterninae). While our phylogenetic findings illuminate the phylogenetic aspects, the complete story awaits further field observations and in-depth genomic analyses of biochemical pathways used by bioluminescent elateroids., Competing Interests: The authors declare no competing interests., (© 2023 The Author(s).)

Too many students reject the theory of evolution because they view it as incompatible with their religious beliefs. Some have argued that abandoning religious belief is the only way to help religious individuals accept evolution. Conversely, our data support that highlighting faith/evolution compatibility is an effective means to increase student acceptance. We surveyed students enrolled in entry-level biology courses at four religiously affiliated institutions. At each university, teachers gave students a presentation that demonstrated potential compatibility between evolution and faith within the teachings of each university's respective religious affiliation. Students were asked to evaluate their own beliefs about evolution both before and after this instruction. After instruction at each university, students showed significant gains in evolution acceptance without abandoning their religious beliefs. These results demonstrate that giving religious students the opportunity to reconcile their religious beliefs with the theory of evolution under the influence of intentional instruction on the compatibility of belief and evolution can lead to increased evolution acceptance among religious students.

The convergent evolution of analogous features is an evolutionary process occurring independently across the tree of life. From the evolution of echolocation, prehensile tail, viviparity, or winged flight, environmental factors often drive this astonishing phenomenon. However, convergent evolution is not always conspicuous or easily identified. Giant damselflies count among the largest flying insects on Earth, and have astonishing ecologies including orb-web spider plucking and oviposition in phytotelmata. One species occurs in the Afrotropics and 18 species are found in the Neotropics. Convergent evolution was historically hypothesized based on the ecological and morphological affinities of these two geographically distant lineages but was not supported by earlier phylogenetic inferences supporting their monophyly. Using a molecular supermatrix approach and a large selection of outgroups, we revisit and reject the monophyly of Afrotropical and Neotropical giant damselflies that is otherwise supported by a morphological phylogeny. Molecular divergence time estimation suggests an origin of Afrotropical giant damselflies in the late Paleogene, and of Neotropical ones at the Cretaceous/Paleogene boundary, thereby rejecting a long-standing West Gondwana vicariance hypothesis. The strong ecological and morphological resemblances between these two independent lineages represents an astonishing case of Amphi-Atlantic tropical convergent evolution., (© 2019 The Author(s). Evolution © 2019 The Society for the Study of Evolution.)

Mimetic wing coloration evolves in butterflies in the context of predator confusion. Unless butterfly eyes have adaptations for discriminating mimetic color variation, mimicry also carries a risk of confusion for the butterflies themselves. Heliconius butterfly eyes, which express recently duplicated ultraviolet (UV) opsins, have such an adaptation. To examine bird and butterfly color vision as sources of selection on butterfly coloration, we studied yellow wing pigmentation in the tribe Heliconiini. We confirmed, using reflectance and mass spectrometry, that only Heliconius use 3-hydroxy-DL-kynurenine (3-OHK), which looks yellow to humans but reflects both UV- and long-wavelength light, whereas butterflies in related genera have chemically unknown yellow pigments mostly lacking UV reflectance. Modeling of these color signals reveals that the two UV photoreceptors of Heliconius are better suited to separating 3-OHK from non-3-OHK spectra compared with the photoreceptors of related genera or birds. The co-occurrence of potentially enhanced UV vision and a UV-reflecting yellow wing pigment could allow unpalatable Heliconius private intraspecific communication in the presence of mimics. Our results are the best available evidence for the correlated evolution of a color signal and color vision. They also suggest that predator visual systems are error prone in the context of mimicry., (© 2011 by The University of Chicago.)

The butterfly Heliconius erato can see from the UV to the red part of the light spectrum with color vision proven from 440 to 640 nm. Its eye is known to contain three visual pigments, rhodopsins, produced by an 11-cis-3-hydroxyretinal chromophore together with long wavelength (LWRh), blue (BRh) and UV (UVRh1) opsins. We now find that H. erato has a second UV opsin mRNA (UVRh2)-a previously undescribed duplication of this gene among Lepidoptera. To investigate its evolutionary origin, we screened eye cDNAs from 14 butterfly species in the subfamily Heliconiinae and found both copies only among Heliconius. Phylogeny-based tests of selection indicate positive selection of UVRh2 following duplication, and some of the positively selected sites correspond to vertebrate visual pigment spectral tuning residues. Epi-microspectrophotometry reveals two UV-absorbing rhodopsins in the H. erato eye with lambda(max) = 355 nm and 398 nm. Along with the additional UV opsin, Heliconius have also evolved 3-hydroxy-DL-kynurenine (3-OHK)-based yellow wing pigments not found in close relatives. Visual models of how butterflies perceive wing color variation indicate this has resulted in an expansion of the number of distinguishable yellow colors on Heliconius wings. Functional diversification of the UV-sensitive visual pigments may help explain why the yellow wing pigments of Heliconius are so colorful in the UV range compared to the yellow pigments of close relatives lacking the UV opsin duplicate.