Morphological and RAPD analysis of hybridization between Quercus affinis and Q. laurina (fagaceae), two Mexican red oaks

Quercus affinis and Q. laurina are two closely related Mexican red oaks with partially overlapping distributions. Within the area of overlap, there are localities where morphological intergradation occurs. A previous hypothesis explained this pattern as a result of secondary contact between the two species, followed by hybridization and introgression. This possibility was analyzed here by examining foliar and genetic variation in 16 localities situated along a macrogeographic gradient, which included morphologically representative populations of both species and populations from within the area of overlap. Maximum-likelihood hybrid index scores calculated from nine semi-diagnostic RAPD markers indicated a shift in the genetic composition of populations from one species to the other along the macrogeographic gradient, with genetically intermediate populations situated in the area of overlap. Foliar variation followed a partially congruent pattern, but Q. laurina-like morphology predominated in some of the genetically intermediate populations. There were several instances of correlated frequency changeovers of single RAPD markers and morphological characters along the macrogeographic gradient and a few cases of markedly parallel patterns between markers. The results were interpreted as consistent with a hypothesis of secondary contact between the two oak species that has resulted in some differential introgression among markers.     

Geographic structure of genetic and phenotypic variation in the hybrid zone between Quercus affinis and Q. laurina in Mexico

Analyzing the structure of hybrid zones is important for inferring their origin, dynamics and evolutionary significance. We examined the geographic structure of phenotypic and genetic variation in the contact zone between two Mexican red oaks, Quercus affinis and Q. laurina. A total of 105 individuals from seven populations were sampled along a 600‐km latitudinal gradient representing the distribution area of the two species and their contact zone. Individuals were genotyped for nine nuclear and four chloroplast DNA microsatellite loci (ncSSR and cpSSR, respectively), and characterized for several leaf and acorn traits. The cpSSR data revealed extensive haplotype sharing among populations of the two species, while a Bayesian assignment analysis based on ncSSRs identified two main genetic groups, each corresponding to one of the species, and two populations in the contact zone showing evidence of admixture. The proportion of genetic ancestry in the populations was strongly associated with latitude and showed a pattern of variation with the shape of a narrow sigmoidal cline. The variation in three of the seven phenotypic traits was partially congruent with molecular variation, while the other traits did not conform to a geographic cline but instead were correlated with environmental variables. In conclusion, the hybrid zone between the two oak species has some of the characteristics of a tension zone, but heterogeneous variation across traits suggests differential introgression and the action of extrinsic selection.     

Clonal and genetic structure of two Mexican oaks: Quercus eduardii and Quercus potosina (Fagaceae)

Quercus eduardii and Q. potosina are dominant oak species in Sierra Fría, Aguascalientes, Mexico. These species have been exploited for multiple purposes since the 16th century. Both species produce clonal offspring through root suckering and acorns through sexual reproduction. To understand clonality for the implementation of the most adequate actions for the conservation of these species, we addressed the following questions: (a) what is the spatial clonal structure of both species? (b) How much clonal and genetic diversity is maintained in these species? Random Amplified Polymorphic DNAs (RAPDs) were used as molecular markers for these analyses. Genets of both species have few ramets and these grow close the parent tree. Autocorrelation analyses at the ramet level showed an aggregated distribution at short distances and a random spatial distribution at larger distances. Also, at the genet level the autocorrelation analyses showed a random distribution. Clonal diversity was high in both species (Q. eduardii: D=0.963, G/N=0.60; Q. potosina: D=0.985, G/N=0.65). Genetic diversity was high within populations (Q. eduardii: H _e =0.33±0.11; Q. potosina: H _e =0.35±0.11). Low levels of genetic differentiation among populations were observed (Q. eduardii ? _st =0.19, P < 0.002; Q. potosina ? _st =0.13, P < 0.002). Both species maintain high levels of clonal and genetic diversity, probably due to successful sexual reproduction, which allows gene flow among populations. Conservation and/or reforestation programs must include seed collections and germplasm banks. Due to the small genet size and the high clonal diversity of these species, seeds can be collected in any place in Sierra Fría, Aguascalientes.     

Comparative analysis of micromorphological characters in two distantly related Mexican oaks, Quercus conzattii and Q. eduardii (Fagaceae), and their hybrids

Interspecific hybridization occurs with high frequency in the genusQuercus, but few studies have analyzed and compared micromorphological characters in putative parental species and their hybrids.Quercus eduardii andQ. conzattii are two Mexican black oak species that, although distantly related, have formed at least one population of hybrid origin, where individuals with intermediate macromorphology are present. The purpose of this investigation was to analyze the degree of differentiation in micromorphological characters between the two species and to assess the expression of these characters in individuals with intermediate macromorphology. Foliar trichomes, epicuticular waxes, stomata, and pollen grains, were examined using scanning electron microscopy (SEM) in the three types of individuals (Q. conzatti, Q. eduardii, and intermediates). Trichome density was quantified with light microscopy. Types of trichomes present, length of trichome arms, types of epicuticular wax on the leaf surfaces, and the position of stomata with respect to the foliar surface were characters useful to differentiate betweenQ. conzattii andQ. eduardii. Plants with intermediate macromorphology displayed a pattern of micromorphological characters that were identical to one parental species (Q. conzattii), or extreme or novel relative to both species.     

Environmental Heterogeneity and Population Differentiation in Plasticity to Drought in <Emphasis Type="Italic">Convolvulus Chilensis</Emphasis> (Convolvulaceae)

Plant populations may show differentiation in phenotypic plasticity, and theory predicts that greater levels of environmental heterogeneity should select for higher magnitudes of phenotypic plasticity. We evaluated phenotypic responses to reduced soil moisture in plants of Convolvulus chilensis grown in a greenhouse from seeds collected in three natural populations that differ in environmental heterogeneity (precipitation regime). Among several morphological and ecophysiological traits evaluated, only four traits showed differentiation among populations in plasticity to soil moisture: leaf area, leaf shape, leaf area ratio (LAR), and foliar trichome density. In all of these traits plasticity to drought was greatest in plants from the population with the highest interannual variation in precipitation. We further tested the adaptive nature of these plastic responses by evaluating the relationship between phenotypic traits and total biomass, as a proxy for plant fitness, in the low water environment. Foliar trichome density appears to be the only trait that shows adaptive patterns of plasticity to drought. Plants from populations showing plasticity had higher trichome density when growing in soils with reduced moisture, and foliar trichome density was positively associated with total biomass. Co-ordinating editor: F. Stuefer     

Chloroplast DNA variation in the Quercus affinis-Q. laurina complex in Mexico: geographical structure and associations with nuclear and morphological variation

The geographical distribution of chloroplast DNA (cpDNA) variation in 39 populations of two hybridizing Mexican red oaks, Quercus affinis and Q. laurina, was investigated using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Six haplotypes were identified. Of these, two (H1 and H4), separated by four mutations, had high frequencies (58 and 23% of the individuals, respectively) and were present across the whole geographical range of both species, often co occurring in the same populations. The other four haplotypes were rare, geographically restricted, and are probably derived from the two frequent haplotypes. Latitudinal or other clinal patterns in diversity levels or haplotype composition of populations were not apparent. The pattern of haplotype distribution was characterized by some mosaicism, with contrasting populations often situated in proximity. Average within-population diversity (hS=0.299) and population differentiation (GST=0.499) were, respectively, higher and lower than values reported in previous studies of oak species. There was evidence for phylogeographical structure, as indicated by NST (0.566) being significantly higher than GST. Haplotypic variation was largely species-independent, although some very weak associations were detected between haplotypes H1 and H4 and morphological and nuclear molecular variation correspondingly characterizing Q. affinis and Q. laurina. These oaks probably did not experience a marked restriction to one or a few particular subregions of their present range during the last glacial cycle. It is more likely that substantial populations persisted throughout several episodes of climatic change, but experienced recurrent latitudinal and altitudinal migrations which may have caused the widespread distribution of haplotypes H1 and H4 and frequent intermixing of populations.     

Drought response of two Mexican oak species, Quercus laceyi and Q. sideroxyla (Fagaceae), in relation to elevational position

To investigate the relationship between the altitudinal distribution of Quercus laceyi and Q. sideroxyla and their physiological responses to drought, we measured relative water content (RWC), water potentials (Ψ(predawn) and Ψ(midday)), photosynthesis (A(max)), stomatal conductance (g), chlorophyll fluorescence (F(v)/F(m)), and spectral reflectance (400-1100 nm) five times during a 7 wk acute drought. Quercus laceyi was drought tolerant, while Q. sideroxyla was a drought avoider; Q. laceyi tolerated lower RWC (Q. sideroxyla = 54%, Q. laceyi = 44%), Ψ(pd) (Q. sideroxyla = -2.6 MPa, Q. laceyi = -3.3 MPa), and Ψ(md) (Q. sideroxyla = -4.5 MPa, Q. laceyi = -6.6 MPa). The F(v)/F(m) also declined first in Q. sideroxyla in wk 6, whereas F(v)/F(m) did not decline in Q. laceyi until wk 7. A(max) and g fell in wk 4, 6, and 7 in drought seedlings of both species, suggesting a decline in CO(2) assimilation during the drought. Leaf spectral reflectance increased with time in response to decreases in leaf photosynthetic pigment concentrations in latter weeks of the drought. The results suggest a close association between the altitudinal distributions of these species and their adaptation to water stress.     

Clonal population structure and genetic variation in sand-shinnery oak,Quercus havardii (Fagaceae)

We investigated clonal population structure and genetic variation in Quercus havardii (sand-shinnery oak), a deciduous rhizomatous shrub that dominates vegetation by forming uninterrupted expanses of ground cover over sandy deposits on the plains of western Texas, western Oklahoma, and eastern New Mexico. Isozyme electrophoresis (15 loci coding 11 enzymes) was used to recognize and map clones arrayed in a 2000-m transect (50-m sample intervals) and a 200 × 190 m grid (10-m sample intervals). Ninety-four clones were discovered, 38 in the transect and 56 in the grid, resulting in an estimated density of ～15 clones per hectare. Clones varied greatly in size (～100-7000 m), shape, and degree of fragmentation. The larger clones possessed massive interiors free of intergrowth by other clones, while the smaller clones varied in degree of intergrowth. The population maintained substantial levels of genetic variation (P = 60%, A = 2.5, H(exp) = 0.289) comparable to values obtained for other Quercus spp. and for other long-lived perennials. The population was outcrossing as evidenced by conformance of most loci to Hardy-Weinberg expected genotype proportions, although exceptions indicated a limited degree of population substructuring. These data indicate that despite apparent reproduction primarily through vegetative means, Q. havardii possesses conventional attributes of a sexual population.     

Morphometric variation in oaks of the Apostle Islands in Wisconsin: evidence of hybridization between Quercus rubra and Q. ellipsoidalis (Fagaceae)

The Apostle Islands in Lake Superior are populated by trees that are clearly related to Quercus rubra L. However, several islands have trees with morphological characteristics suggestive of hybridization with Q. ellipsoidalis Hill. Leaf specimens were collected from trees in five locations: the outermost island, an intermediate island, the nearest-shore island, the northeast shoreline, and an inland forest about 24 km from the shoreline. Seventeen landmarks were digitized for two to five leaves per tree. These landmarks were used to generate nine linear characters and three angles. These characters, along with the number of bristle tips per leaf, were used in various combinations for several principal component analyses. In addition, the landmark configurations were examined using rotational-fit methods. The patterns observed in both types of analysis indicate phenotypic variation coincident with a line connecting the two most distant sample sites. The location nearest the geographic center of this line is also nearest the center of the two-dimensional view of phenotypic variation. Trees at each site illustrate a distinctive pattern in the rotational-fit analyses, and patterns of co-variation in the morphometric characters are different for each site. The observed morphometric variation is consistent with the hypothesis that there is hybridization between these two species, most likely in the form of introgression from Q. ellipsoidalis into Q. rubra.     

Natural hybridisation among Quercus glabrescens,Q. rugosa and Q. obtusata (Fagaceae): Microsatellites and secondary metabolites markers

• Natural hybridisation has significant ecological, genetic and evolutionary consequences altering morphological and chemical characters of individuals. Quercus glabrescens, Q. rugosa and Q. obtusata are white oak species well separated by their morphological characters when they occur in allopatry in Mexican temperate forests. However, in sympatry, individuals with atypical morphology have been observed, suggesting hybridisation events.
• In this study, we determined, with microsatellites and secondary metabolites, if interspecific gene flow occurs when these three oak species coexist in sympatry. In total, 180 individuals belonging to seven populations [three allopatric (one for each parental species) and four sympatric sites] were analysed.
• Allopatric populations represent well‐defined genetic groups and the sympatric populations showed genetic evidence of hybridisation between Q. glabrescens × Q. rugosa and Q. glabrescens × Q. obtusata. The hybridisation percentage varied between sites and combination of involved species. We registered the presence of unique flavonoid compounds for Q. glabrescens (caffeic acid and flavonol 2), Q. rugosa (flavonol 5) and Q. obtusata (flavonol 1). Three compounds (quercetin rhamnoside, flavonol 3 and alkyl coumarate) were expressed in all taxa. Finally, the hybrid genotypes identified in this study (Q. glabrescens × Q. rugosa and Q. glabrescens × Q. obtusata) showed specific chemical profiles, resulting from a combination of those of their parental species.
• These results show that hybridisation events between these oak species alter chemical expression of secondary metabolites, creating a mosaic of resources and conditions that provide the substrate for different combinations of foliar‐associated species such as herbivores, endophytic fungi or epiphyte plants.

     

High genetic diversity and stable Pleistocene distributional ranges in the widespread Mexican red oak Quercus castanea Née (1801) (Fagaceae)

The Mexican highlands are areas of high biological complexity where taxa of Nearctic and Neotropical origin and different population histories are found. To gain a more detailed view of the evolution of the biota in these regions, it is necessary to evaluate the effects of historical tectonic and climate events on species. Here, we analyzed the phylogeographic structure, historical demographic processes, and the contemporary period, Last Glacial Maximum (LGM) and Last Interglacial (LIG) ecological niche models of Quercus castanea, to infer the historical population dynamics of this oak distributed in the Mexican highlands. A total of 36 populations of Q. castanea were genotyped with seven chloroplast microsatellite loci in four recognized biogeographic provinces of Mexico: the Sierra Madre Occidental (western mountain range), the Central Plateau, the Trans‐Mexican Volcanic Belt (TMVB, mountain range crossing central Mexico from west to east) and the Sierra Madre del Sur (SMS, southern mountain range). We obtained standard statistics of genetic diversity and structure and tested for signals of historical demographic expansions. A total of 90 haplotypes were identified, and 29 of these haplotypes were restricted to single populations. The within‐population genetic diversity was high (mean h_S = 0.72), and among‐population genetic differentiation showed a strong phylogeographic structure (N_ST = 0.630 > G_ST = 0.266; p < .001). Signals of demographic expansion were identified in the TMVB and the SMS. The ecological niche models suggested a considerable percentage of stable distribution area for the species during the LGM and connectivity between the TMVB and the SMS. High genetic diversity, strong phylogeographic structure, and ecological niche models suggest in situ permanence of Q. castanea populations with large effective population sizes. The complex geological and climatic histories of the TMVB help to explain the origin and maintenance of a large proportion of the genetic diversity in this oak species.     

Mitochondrial DNA variation and GIS analysis confirm a secondary origin of geographical variation in the bushcricket Ephippiger ephippiger (Orthoptera: Tettigonioidea), and resurrect two subspecies

Geographic variation within species can originate through selection and drift in situ (primary variation) or from vicariant episodes (secondary variation). Most patterns of subspecific variation within European flora and fauna are thought to have secondary origins, reflecting isolation in refugia during Quaternary ice ages. The bushcricket Ephippiger ephippiger has an unusual pattern of geographical variability in morphology, behaviour and allozymes in southern France, which has been interpreted as reflecting recent primary origins rather than historical isolation. Re-analysis of this variation using Geographical Information Systems (GIS) suggests a possible zone of hybridization within a complex pattern of geographical variation. Here we produce a genetic distance matrix from restriction fragment length polymorphism (RFLP) bandsharing of an approximately 4.5 kb fragment of mitochondrial DNA (mtDNA), and compare this with predictions resulting from the GIS analysis. The mtDNA variation supports a postglacial origin of geographical variation. Partial Mantel test comparisons of genetic distances with matrices of geographical distance, relevant environmental characteristics and possible refugia show refugia to be the best predictors of genetic distance. There is no evidence to support isolation by distance. However, environmental contrasts do explain significant variation in genetic distance after allowing for the effect of refugial origin. Also, a neighbour-joining tree has a major division separating eastern and western forms. We conclude that the major source of variation within the species is historical isolation in glacial refugia, but that dispersal, hybridization and selection associated with environmental features has influenced patterns of mtDNA introgression. At least two valid subspecies can be defined.     

Hybridization of European oaks (Quercus ilex × Q. robur) results in a mixed isoprenoid emitter type

European oaks have been reported to emit isoprene or monoterpenes derived from recently fixed photosynthetic carbon. The emission type is plant species specific and can be used as chemo‐taxonomic marker. In the present article the isoprenoid biochemical properties of mature Quercus × turneri‘Pseudoturneri’ hybrids resulting from a crossing of a Mediterranean evergreen monoterpene‐emitting species (subgenus Sclerophyllodrys; Quercus ilex L.) and an isoprene‐emitting deciduous oak species (subgenus Lepidobalanus; Quercus robur L.) are described. Both species are compared with respect to the capacity for isoprenoid synthesis and the actual isoprenoid emission pattern of different tree‐types. The analysis showed that the oak hybrid combines properties of both parental species. Furthermore, it could be shown that the enzyme activities of isoprene synthase and monoterpene synthases are reflected in the isoprenoid emission pattern of the hybrids as well as in the observed emission rates.     

Ecotype differentiation and coexistence of two parapatric tetraploid subspecies of cocksfoot (Dactylis glomerata) in the Alps

Two tetraploid subspecies of Dactylis glomerata L., subsp. reichenbachii (Hausm.) Stebbins et Zohary and subsp. glomerata , occur in the French Alps. The former is confined to dolomitic, south-facing, alpine lawns above 2000 m, whereas the latter occurs in non-dolomitic habitats in subalpine meadows mainly below 1900 m. Previous studies of allozyme variation have shown that genetic introgression between the two subspecies occurs over large areas. By contrast, morphologically intermediate individuals only occur in an extremely narrow area, suggesting that the morphological and physiological differences between the two subspecies is of adaptive significance. A reciprocal clone transplant experiment was set up to examine (1) any genetic differences between subspecies indicative of ecotypic differentiation in relation to habitat characteristics and (2) the level of phenotypic plasticity in the two subspecies. Genetic differentiation was confirmed by a statistically significant taxon × site interaction effect in anova for all traits studied. The glomerata populations produced more tillers, longer leaves and higher culms in all sites, especially in their home environment. However, reichenbachii populations produced more seeds than the glomerata populations in the original reichenbachii environment, suggesting ecotypic differentiation between the two subspecies. This result might also explain why the glomerata subspecies is unable to colonize dolomitic habitats occupied by the reichenbachii subspecies. The reichenbachii populations showed less plasticity than the glomerata populations for leaf length and floriferous tiller number, a result which is discussed in the context of the response of plants from productive and non-productive habitats to environmental variation.     

Variation in morphological traits in a recent hybrid zone between closely related Quercus liaotungensis and Q. mongolica (Fagaceae)

Aims Hybridization usually leads to gene introgression between related species in hybrid zones, associated with complex patterns of morphological variation. Nevertheless, previous studies have tended to ignore the effects of geographic variation in hybridization rates on species taxonomy. This study aims to investigate the variation of morphological traits between two sympatric and taxonomically confused oak species, Quercus liaotungensis and Q. mongolica, and reveal the effects of hybridization rates on morphological traits and the taxonomic boundary.Methods We used seven microsatellite loci to evaluate species status and measured 15 morphological traits in 26 trees in the recent hybrid zone between Q. liaotungensis and Q. mongolica, and we characterized the differences between the two oak species and their hybrids for the investigated traits.Important findings Molecular analyses indicated that 74% of 78 sampled maternal trees were hybrids between Q. liaotungensis and Q. mongolica although the observed morphological variation suggested that they had remained distinct species. Across all of the differentiated leaf and reproductive traits, the hybrids expressed patterns similar to Q. liaotungensis, which may suggest dominant expression of parental characters. These results are consistent with our expectation that hybrids will be difficult to distinguish from parental species in a recent hybrid zone.     

The effects of seed size, cotyledon reserves, and herbivory on seedling survival and growth in Quercus rugosa and Q. laurina (Fagaceae)

In a greenhouse experiment, seedling survival of two oak species (Quercus rugosa and Q. laurina) was greatly affected by the excision of cotyledons 1 mo after germination, with a greater impact on Q. laurina. The effect of seed size was also significant for both species, with a positive correlation between seed mass and survival and growth. The effect of cotyledon excision on seedling growth persisted throughout the first growing season in Q. rugosa and was not analyzed for Q. laurina due to the low number of seedlings that survived cotyledon excision. Seed size significantly affected seedling height, diameter, leaf area, and biomass at 6 mo. Seed size and cotyledon retention affected the ability of Q. rugosa to recover from herbivory, as both factors had a significant effect on relative growth rates after aerial biomass removal. The results show that seedlings originating from large seeds can better endure loss of cotyledons and aerial biomass and thus are better equipped to confront stress early in their lives.     

Natural hybridisation between kermes (Quercus coccifera L.) and holm oaks (Q. ilex L.) revealed by microsatellite markers

Hybridisation between species of the genus Quercus is a common phenomenon as a result of weak reproductive isolation mechanisms between phylogenetically close species that frequently co-occur in mixed stands. In this study, we use microsatellite markers to analyse introgression between kermes ( Quercus coccifera L.) and holm ( Q. ilex L.) oak, two closely related taxa that frequently dominate the landscape in extensive areas in the Mediterranean region. All tested microsatellites amplified and were polymorphic in both kermes and holm oaks. Bayesian admixture analyses showed a good correspondence between each species and one of the two inferred genetic clusters. Five sampled individuals were a priori tentatively identified as hybrids on the basis of intermediate morphological characteristics, and it was confirmed that they also presented mixed genotypes. However, we also detected different levels of genetic introgression among morphologically pure individuals, suggesting that successful backcrossing and/or reduced phenotypic expression of genetic variance in certain individuals may have resulted in strong convergence towards a single species phenotype.     

Quantitative variation within and among populations of Arabis serrata Fr. & Sav. (Brassicaceae)

Phenotypic and genetic variation within and among eight populations of Arabis serrata are documented in this study. This species shows great morphological variation throughout its geographical distribution in Japan. Plants are located in habitats with different types of soils and degree of disturbance. Half-sibs progenies from eight populations were collected and cultivated in a garden experiment. Nine morphological traits representing size and shape of rosette leaves were recorded. Univariate analyses of measured traits showed that phenotypic means differed among populations for all characters. Leaves of plants from disturbed habitats had the longest petioles (lanceolate) and plants from limestone habitats showed the most roundness in leaf shape (ovate). The northernmost populations always revealed the smallest leaves. Multivariate principal component analyses also showed that leaf shape and size varied among populations. The first three principal components explained 98.5% of the variation. Coefficients of variation had a very wide range and differed from one population to another. Some traits (e.g. leaf width/leaf length ratio) were consistently less variable while others (e.g. leaf area and petiole length) were more plastic. All traits had significant genetic variance in all populations. Intra-class correlation coefficients differed for most of the traits and each population presented a different range of values. Most of the leaf traits were intercorrelated in all the populations studied, although some populations were integrated more tightly for some traits. Populations of A. serrata are differentiated in phenotypic means but they display a mosaic of traits with slight morphological differences in each locality (i.e. a quantitative genetic variation). Some traits can be correlated to the habitats that they occupy but for some of them it is difficult to assign an actual adaptive value.     

Subtle variation in size and shape of the whole forewing and the red band among co‐mimics revealed by geometric morphometric analysis in Heliconius butterflies

Heliconius are unpalatable butterflies that exhibit remarkable intra‐ and interspecific variation in wing color pattern, specifically warning coloration. Species that have converged on the same pattern are often clustered in Müllerian mimicry rings. Overall, wing color patterns are nearly identical among co‐mimics. However, fine‐scale differences exist, indicating that factors in addition to natural selection may underlie wing phenotype. Here, we investigate differences in shape and size of the forewing and the red band in the Heliconius postman mimicry ring (H. erato phyllis and the co‐mimics H. besckei, H. melpomene burchelli, and H. melpomene nanna) using a landmark‐based approach. If phenotypic evolution is driven entirely by predation pressure, we expect nonsignificant differences among co‐mimics in terms of wing shape. Also, a reinforcement of wing pattern (i.e., greater similarity) could occur when co‐mimics are in sympatry. We also examined variation in the red forewing band because this trait is critical for both mimicry and sexual communication. Morphometric results revealed significant but small differences among species, particularly in the shape of the forewing of co‐mimics. Although we did not observe greater similarity when co‐mimics were in sympatry, nearly identical patterns provided evidence of convergence for mimicry. In contrast, mimetic pairs could be distinguished based on the shape (but not the size) of the red band, suggesting an “advergence” process. In addition, sexual dimorphism in the red band shape (but not size) was found for all lineages. Thus, we infer that natural selection due to predation by birds might not be the only mechanism responsible for variation in color patterns, and sexual selection could be an important driver of wing phenotypic evolution in this mimicry ring.