Biology subjects

Lamas, G.

Publications and source records attributed to Lamas, G..

5 recordsLinked to original sources

bioRxiv2025

Environmental Variation Promotes Convergent Evolution and Rapid Diversification of Wing Shape and Color in Skipper Butterflies

Predation is a key driver of speciation and phenotypic diversification, yet how antipredator traits evolve and persist over evolutionary time remains poorly understood. We generated target sequence capture and whole-genome sequencing data for the skipper butterfly subfamily Eudaminae (Hesperiidae) to test whether antipredator defenses, in interaction with environmental variation, promote diversification. We focus on two antipredation wing traits: hindwing tails, which deflect predator attacks, and blue-green coloration, which may enhance motion dazzle and be used as warning coloration. Applying phylogenomics, morphometrics, and comparative methods, we model trait evolution in relation to diel activity and geographic distribution and find that hindwing tails repeatedly evolved at least seven times and blue-green coloration at least fifteen times. Both traits are associated with elevated speciation rates, but evolutionary transitions toward tailless wings and non-iridescent coloration occurred more frequently than trait gains, indicating high evolutionary lability of these antipredator defenses. Trait loss, particularly pronounced in tropical diurnal species, may reflect trade-offs in flight performance, shifts in predation guilds, or the evolution of alternative defensive traits. Our findings highlight rampant convergent evolution of wing traits that are under strong predator-mediated selection. By identifying how antipredator defenses and environmental contexts influence phenotypic and species diversification, this study provides new insights into the ecological and evolutionary processes underlying insect diversity.

evolutionary biology↗

bioRxiv2025

Genetic parallelism underpins convergent mimicry coloration across Lepidoptera

Convergent evolution, the repeated evolution of similar phenotypes in response to the same selective pressures across multiple lineages, is widespread in nature. The extent to which the same genetic mechanisms contribute to convergent evolution could reveal whether the pathway towards these optimal endpoints is flexible or constrained to follow a particular route. Although mimicry of aposematic colour patterns is well known in Lepidoptera, our knowledge of the genetic basis of these convergent patterns is mostly restricted to a few closely-related species. Here we study the genetic basis of mimicry across seven species of Ithomiini and Heliconius butterflies and a day-flying Chetone moth, representing lineages that diverged between [~]1-120 Mya, each presenting similar colour pattern switches. In all the butterfly species, the genetic variants most strongly associated with convergent colour pattern switches are similarly located in non-coding regions near the genes ivory and optix. Colour pattern variation in the moth is associated with a [~]1 Mb inversion around ivory paralleling the supergene architecture of the co-mimic Heliconius numata. In contrast to previous studies in Heliconius, there is limited evidence of alleles shared by means of hybridization in convergence among closely-related ithomiine species. Repeated parallel evolution of regulatory switches via reuse of the same two genes suggests that convergent colour pattern evolution is highly constrained, even across large evolutionary timescales.

evolutionary biology↗

bioRxiv2020

The latitudinal diversity gradient in brush-footed butterflies (Nymphalidae): conserved ancestral tropical niche but different continental histories.

The latitudinal diversity gradient (LDG) is arguably one of the most striking patterns in nature. The global increase in species richness toward the tropics across continents and taxonomic groups stimulated the formulation of many hypotheses to explain the underlying mechanisms of this pattern. We evaluated several of these hypotheses to explain spatial diversity patterns in the butterfly family, Nymphalidae, by assessing the contributions of speciation, extinction, and dispersal to the LDG, and also the extent to which these processes differ among regions at the same latitude. We generated a new, time-calibrated phylogeny of Nymphalidae based on 10 gene fragments and containing ca. 2,800 species ([~]45% of extant diversity). Neither speciation nor extinction rate variations consistently explain the LDG among regions because temporal diversification dynamics differ greatly across longitude. For example, we found that Neotropical nymphalid diversity results from low extinction rates, not high speciation rates, and that biotic interchanges with other regions were rare. Southeast Asia was also characterized by a low speciation rate but, unlike the Neotropics, was the main source of dispersal events through time. Our results suggest that global climate change throughout the Cenozoic, particularly during the Eocene-Oligocene transition, combined with the conserved ancestral tropical niches, played a major role in generating the modern LDG of butterflies.

ecology↗

bioRxiv2017

Renewed diversification following Miocene landscape turnover in a Neotropical butterfly radiation

\"This preprint has been reviewed and recommended by Peer Community In Evolutionary Biology (http://dx.doi.org/10.24072/pci.evolbiol.100032)\"\n\nThe Neotropical region has experienced a dynamic landscape evolution throughout the Miocene, with the large wetland Pebas occupying western Amazonia until 11-8 my ago and continuous uplift of the Andes mountains along the western edge of South America. Although the complex dynamics between the Andes and Amazonia may have strongly affected the trajectory of Neotropical biodiversity, there is little evidence for such an influence from time-calibrated phylogenies of groups that diversified during this period. Here, we generate one of the most comprehensive time-calibrated molecular phylogenies of a group of Neotropical insects: the butterfly tribe Ithomiini. Our tree includes 340 species (87% of extant species), spanning 26 million years of diversification in the Neotropics. We investigate temporal and spatial patterns of diversification, focusing on the influence of Miocene landscape tranformations on the dynamics of speciation, extinction and biotic interchanges at the Amazonia/Andes interface. We find that Ithomiini likely began diversifying at the interface between the Andes and the Amazonia around 26.4 my ago. Five subtribes with a very low extant diversity started diversifying early in western Amazonia, but a rapid decrease in diversification rate due to increased extinction rate between 20 and 10 my ago suggests a negative impact of the Pebas wetland system on these early lineages. By contrast, the clade containing the five most species-rich subtribes (85% of extant species) was characterized by a high, positive net diversification rate. This clade diversified exclusively in the Central Andes from 20 to 10 my ago. After the demise of the Pebas system (11-8 my ago), we found a sudden increase of interchanges with the Northern Andes and Amazonia, followed by local diversification, which led to a substantial renewal of diversification. In general, ecological turnovers throughout the Miocene strongly determined the dynamics of speciation, and extinction and interchanges, and appear as a key driving force shaping the regions current extraordinary biodiversity.

evolutionary biology↗

bioRxiv2017

North Andean origin and diversification of the largest ithomiine butterfly genus

The Neotropics harbour the most diverse flora and fauna on Earth. The Andes are a major centre of diversification and source of diversity for adjacent areas in plants and vertebrates, but studies on insects remain scarce, even though they constitute the largest fraction of terrestrial biodiversity. Here, we combine molecular and morphological characters to generate a dated phylogeny of the butterfly genus Pteronymia (Nymphalidae: Danainae), which we use to infer spatial, elevational and temporal diversification patterns. We first propose six taxonomic changes that raise the generic species total to 53, making Pteronymia the most diverse genus of the tribe Ithomiini. Our biogeographic reconstruction shows that Pteronymia originated in the Northern Andes, where it diversified extensively. Some lineages colonized lowlands and adjacent montane areas, but diversification here remained scarce. The recent colonization of lowland areas was reflected by an increase in the rate of evolution of species elevational ranges towards present. By contrast, speciation rate decelerated with time, with no extinction. The geological history of the Andes and adjacent regions have likely contributed to Pteronymia diversification by providing compartmentalized habitats and an array of biotic and abiotic conditions, and by limiting dispersal between some areas while promoting interchange across others.

evolutionary biology↗